Often, developers are asked not only to identify and solve a problem in the company's work, but also to determine what role it plays in the company's structure. Because it’s more important to understand how a malfunctioning unit interacts with others than simply understanding why it’s malfunctioning. Therefore, identifying any problem begins with studying the work of the company and drawing up its functional model.
Often, developers are asked not only to identify and solve a problem in the company's work, but also to determine what role it plays in the company's structure. Because it’s more important to understand how a malfunctioning unit interacts with others than simply understanding why it’s malfunctioning. Therefore, identifying any problem begins with studying the work of the company and drawing up its functional model.
You will say that the manager should have a functional model of the company, regardless of what kind of company he is talking about. But, as practice shows, in most cases this model is absent.
Graphics advantage
What are IDEF0 models? Graphic schemes with their own characteristics and the rules for their construction. Why graphics? Because it is effective. This can be seen in several examples.
Let's imagine that the military plan of military operations was explained in words, and not with the help of maps with graphic symbols applied to them. Now it seems impossible, but until the second half of the 19th century it was exactly so. Graphics help to understand what to explain and, accordingly, to understand what is difficult enough.
The same is with business processes: many technical tasks can be drawn up in the form of graphical notations, which will greatly simplify the task for developers and save money for clients.
Benefits of IDEF0 forIT-specialists
The activities of developers, whether it is, for example, installing a CRM or creating an effective ERP, is associated with making changes to an already established system. And to do it right, you first need to study how this system works. After studying it, the developer writes a commercial proposal in which he sets out his vision of the situation, the actions necessary to solve the problem, as well as the expected result. Such a document can take more than a dozen pages. This, on the one hand, is good, because the client gets the maximum information he is interested in. On the other hand, it takes time to study a lengthy text. successful businessman often not.
So how is it possible to convey the essence without resorting to voluminous texts? Graphics! It is she who allows you to shorten what is written, clearly demonstrating necessary information... After all, one image can replace hundreds of words. And in relation to the use of graphics in describing business processes, this is 100% true.
Let's first understand what notation and IDEF0 are and what they are for.
Notation for describing business processes: what is it
Notation is a format in which business processes are represented in the form of graphical objects used in modeling, and directly modeling rules. Notation is a kind of graphical language that allows you to represent the functioning of a company, demonstrating the relationship between departments and divisions. That is, the notation can be considered a kind of programming language in business intelligence.
IDEF0 is ...
IDEF0 is a functional modeling method and graphical notation that is used to describe and formalize business processes. The peculiarity of IDEF0 is that this methodology is focused on the subordination of objects. IDEF0 was developed for enterprise automation back in 1981 in the United States.
Functional model of the company
The functional model IDEF0 is blocks, each with multiple inputs and outputs. Each block has controls and mechanisms detailing up to required level... The most important function is located in the upper left corner. It connects to the rest of the arrows and function block descriptions. Each arrow or activity has its own meaning. Due to this, such a model is used to describe any administrative and organizational processes.
Arrow types
Incoming tasks are set.
Outgoing display the result of the activity.
Managers(arrows from top to bottom) are control mechanisms.
Mechanisms(arrows from bottom to top) are used to carry out the necessary work.
When working with a functional model, the following rules are adopted. For example, arrows are named with nouns (rules, plan, etc.), blocks - with verbs (keep records, conclude an agreement).
IDEF0 allows you to exchange information, while due to its versatility and visibility, the exchange participants will easily understand each other. IDEF0 was carefully developed and improved, you can work with IDEF0 using various tools, for example, ERWIN, VISIO, Bussines studio.
IDEF0 also has an undeniable advantage. This technique was developed relatively long ago, and over three decades it has undergone thorough grinding and adjustment. Therefore, it is possible to create a functional model of a company quickly and with a minimum probability of error.
Naturally, there are other methodologies, so why do we recommend IDEF0? You can cut off a piece of metal pipe with a hacksaw, but, you see, it is much easier to do this with a grinder. So it is with IDEF0: there is no more functional tool for modeling, with it you can easily and quickly get the result you need.
How a functional model is created
Let's analyze the creation of a functional model using the example of writing an article.
Main unit will be so called "Article Writing".
What is needed to write an article is reflected in incoming arrows- "Experience", "Further reading".
Control arrows for writing an article - "Outline of the article", "Requirements for registration", "Rules of the Russian language".
The mechanisms are directly the author himself, copywriter, editor, software. How are these mechanisms organized? The author creates the text by recording its audio version. The copywriter transfers the text to text format, focusing on the publication plan, observing the requirements of the publisher and the rules of the Russian language. Then the editor is connected to the work, who checks the article, correcting speech, spelling and punctuation errors. Software is the programs and tools that the participants in the process used to create the article.
All of the above is only a general scheme of work, so it needs to be detailed.
Let's go back to our model and decompose the common block into several related elements.
So, the whole process of writing an article can be divided into 4 stages:
- Prepare an audio version.
- Prepare printed text.
- Editing and preparing text for printing.
- Publication of the article.
The diagram reflects information about which controls and mechanisms are involved at which stage. For example, in order to create high-quality text, the author uses own experience and knowledge, uses the publishing plan and publisher's requirements as a guide. The copywriter, creating the printed version of the text, and the editor, when correcting it, use the rules of the Russian language. To publish an article, for example, in an online publication, special software is required.
When preparing a functional model, the performer is guided by the purpose of its creation and his point of view.
Functional modeling is effectively used when making various management decisions... In our example of the article writing process, there are two specialists - a copywriter and an editor. And with the necessary optimization of project financing according to the scheme, it is not difficult to determine how to do this. The copywriter and the proofreader have similar working methods, so all the work can be offered to the copywriter, since he works directly with the audio text, which the editor cannot do. In this case, the copywriter can be offered to do this work for half of the amount that was intended for the editor. Yes, from this, the quality of the text may be lost, but the optimization task was completed successfully. And it would be more difficult to do this without a visual diagram.
Notation creation processIDEF0
There are many programs for creating notations. Some are designed to create functional models, while others allow you to work with any graphic objects. And for someone, at the first stage, a sheet of paper, a pencil and an eraser is enough.
Before proceeding to the description of the company's work, that is, directly to the creation of the notation of business processes, one should study the principles of the company's functioning. For this, an interview is conducted by a third-party specialist. First of all, the head of the company answers the question, then the specialists who supervise other stages of work.
The first stage of work results in two notations. One will reflect the business processes in their original form. This notation will be created based on the results of the interviews, with every detail to be agreed with the head of the company and its employees. It is imperative that your understanding of the existing business processes in the company coincides with reality, this requires confirmation at all levels.
The second notation can be called "As it should be". It is created on the basis of the first one with the changes made in accordance with the task at hand.
IDEF0 standard and its requirements
We talked about the basic requirements of IDEF0 just above.
- The main element is in the upper left corner.
- Each element must have inbound and outbound arrows. Moreover, the incoming arrows are on the left, on the right - the outgoing ones.
- Control elements are located at the top, mechanisms at the bottom.
- When placing several blocks on one sheet or screen, subsequent ones are placed to the bottom right of the previous one.
- Schemes should be created so that the arrows intersect minimal amount once.
Errors when working with IDEF0
As with any activity, errors occur when performing functional modeling. Let's analyze the most typical ones.
Using multiple colors
It is important to remember that in functional modeling all elements are important, there are no more important or less important ones. When modeling on paper or in one of the computer programs, users try to make the diagram more visual by coloring the blocks and arrows in different colors. However, in practice, this not only does not make the diagram more visual, but, on the contrary, leads to confusion and to the fact that the perception of what is depicted is distorted.
Therefore, the ideal option is a black and white scheme without the use of additional color options. This will not only help eliminate misunderstandings, but also discipline the creator of the model directly, which favorably affects the readability and clarity of the model.
Large number of blocks
When composing a functional model of a company's work, its authors often try to reflect everything, even the smallest details. It turns out a diagram with a huge number of blocks and arrows. As a result, its readability and clarity are reduced.
To avoid this error, use the detail that will be enough to understand the issue. Detailed detailing is prepared only if it is really needed to resolve an important issue.
Changing the structure when fixing errors
When creating a diagram, it is important that more than one process is not left without incoming, outgoing or other important elements... For example, if you want to remove an author from the schema, then you need to remove all elements and arrows directly related to him. If they remain in the scheme, then there will be misunderstanding and confusion, since during detailing they will lead to no one knows where.
The same situation arises with the addition of a block. If you need to fill in any information, check to see if you have provided the required attributes. This should be closely monitored, since when modeling complex business processes, even a slight change in one part will entail changes in another.
Names of blocks and controls
The rules for naming model elements are quite simple, but it is extremely important to remember them: control arrows are called nouns, blocks are called verbs. This rule is written in the IDEF0 standard and helps to avoid confusion and errors.
Benefits of using IDEF0
Visibility. By depicting the work of the company in the form of a diagram, it becomes clear how the company works, where problems can arise and how to prevent their occurrence.
Mutual understanding, exclusion of the possibility of misinterpretation of the scheme. The visibility and accessibility of the functional model, representing the work of the company in the form of blocks and control elements, will help you when discussing with the management of the functioning of their company. By the way, if necessary, a glossary is created for the functional model, which contains all the terms and conventions. Thus, the possibility of misunderstanding between you and the manager, the company's employees, is minimized.
Simplicity and time saving when creating a model. Of course, it takes a lot of time to be good at functional modeling. First of all, you need to learn how to present a huge amount of information in the form of a laconic scheme, i.e. be able to filter and compress the original data. But the time and effort spent on training more than pay off later. After all, it won't take much time to create a functional model and present it in an accessible way.
Minimum probability of error. Working according to the IDEF0 standard requires strict adherence to its rules. This disciplines the performer and eliminates the possibility of errors. In addition, any non-compliance with the standard becomes immediately noticeable.
And finally
For two business analysts, functional models can only be the same if the structure of the company is extremely simple. In other cases, the models will differ from one another. This is natural, because each analyst has his own certain experience, his own understanding of the functioning of the company, his own point of view on how to solve the tasks assigned to him. A business analyst develops a functional model from the point of view of a manager, imagines how he would solve the assigned tasks.
In our opinion, the IDEF0 tool will be useful not only for professional business analysts, but also for those who directly analyze their business and strive to build effective system management.
Description of the business process diagrams "Accounting for computer equipment of the enterprise"
Description of IDEF0 diagram
To build a business process, an IDEF0 diagram was used. The IDEF0 methodology prescribes the construction of a hierarchical system of diagrams - single descriptions of system fragments. First, a description of the system as a whole and its interaction with the outside world is carried out (context diagram). Three levels of the diagram were built:
1. Contextual
2. Functional decomposition
Figure 1 - Context diagram "Accounting computer technology enterprises "
Figure 1 shows a context diagram of the business process "Accounting for enterprise computer equipment". It displays the system as a whole and its interaction with the main external flows of information.
Arrows are indicated in the context diagram.
Arrow types:
Input (input materials: computers and accessories)
Output (output is a report)
Control arrows are documents and managers
The arrows of the mechanisms are employees and equipment
Input information for processing:
Computers - PCs (personal computers) located in the enterprise
Components - materials necessary for upgrading computers (video cards, motherboards, processors, cases, power supplies, memory modules)
Output streams:
Report - a ready-made report on the accounting of computer equipment of the enterprise
Input controls:
Rules - conditions that must be met in order to achieve the goal.
Orders - the task assigned to the enterprise (to keep records of computer equipment at the enterprise using certain information systems)
Managers are directors and general managers of the enterprise.
Input Resources:
PC - computers with the help of which accounting is carried out.
Employees are specialists who carry out instructions assigned by management. After constructing the conceptual model, a functional decomposition was carried out - the system is divided into subsystems and each subsystem is described separately (decomposition diagrams).
Figure 2 shows a functional decomposition of four jobs.
Figure 2 - Functional decomposition "Accounting for enterprise computer equipment"
The following types of work were identified:
1) Registration of deliveries - the process in which the id is assigned to the product, sent to storage, to the warehouse and information about the product is entered into the program.
The work Registration of supplies includes seven boundary arrows (entrance, control, mechanism) and an internal arrow leaves (connection at the entrance).
Arrow communication at the entrance between the works Registration of deliveries and Maintenance of the computer (computer);
Arrows for entry, exit, control are repeated in subsequent works.
2) Computer maintenance - the process in which the assembly, repair and modernization of computers takes place.
The computer maintenance work includes four boundary arrows (input, control, mechanism, output) and several internal arrows (input communication, Feedback at the entrance).
Arrow control - rules, orders, leader;
Arrow connection at the entrance between the jobs Computer maintenance and Placement (entering data into the database), between the jobs Computer maintenance and Reporting (entering data into the database);
3) Placement - the process in which the placement of computers in offices (offices) takes place.
Arrows control - rules, orders, leader;
Arrow mechanism - employees;
Arrow link on input between Spreading and Reporting (assigning an id);
4) Drawing up a report - the final stage of the accounting process, which consists of summarizing totals obtained by performing the previous data of the current accounting.
Then each subsystem is broken down into smaller decompositions, and so on, until the desired level of detail is achieved.
Figure 3 is a diagram showing the work of the Procurement Process in more detail.
As a result of detailing, the main functions were highlighted. The section "Registration of supplies" includes seven main arrows (entry, exit, control, mechanism).
Arrow entry - computers and accessories;
Control arrows are rules, orders and a leader. Forking arrows;
Mechanism arrows, branching - PC, employees;
Arrows for entry, control, mechanisms are repeated in all works.
1) Assignment of numbers - assignment of individual numbers to computers and accessories.
Entry arrows - computers and accessories. Arrow computers are repeated in subsequent works, except for the compilation of the report;
Control arrows - rules, orders and leader;
Mechanism Arrows - PC and Employees;
Arrow link at the entrance between the works Assigning a number and Sending goods to the warehouse (transfer), between Assigning a number and Putting on balance (entering into the base);
2) Sending goods to the warehouse - sending the goods with the assigned number to the warehouse.
Exit Arrow - Computer;
Control arrows - rules, orders and leader.
Arrow link at the entrance between the works "Sending goods to the warehouse" and "Setting on the balance sheet" (quantity);
3) Balancing - entering information into a computer.
Control arrows - rules, orders and leader;
Mechanism Arrows - PC and Employees;
Figure 4 is a diagram detailing computer maintenance in more detail.
As a result of detailing, the main functions performed in the process of servicing a computer were highlighted.
The computer maintenance work includes 4 boundary arrows (input, output, control, mechanism). Internal arrows (input feedback, input communication).
1) Assembly of computers - configuration of computers for individual orders of managers.
Arrow entry - computers;
Control arrows - rules, orders and leader;
Mechanism Arrows - Employees;
Arrow link at the entrance between the works: "Assembling computers" and "Repairing computers" (computer);
2) Computer repair - assembly of computers approved for improvement.
Arrow entry - computers;
Exit arrow - entry into the base;
Control arrows - rules, orders and leader;
Mechanism Arrows - Employees;
Arrows of entry, exit, control, mechanism are branching;
Arrow link at the entrance between the works: "Computer repair" and "Upgrade" (accessories);
3) Upgrade - improvement, improvement, upgrade of the computer.
Exit arrow - entry into the base;
Control arrows - rules, orders and leader;
Mechanism Arrows - Employees;
Arrows of control, mechanism are branching;
Figure 5 shows the Reporting Chart in more detail. The work decomposition. Reporting includes 4 boundary arrows (input, output, control, mechanisms). Internal arrows (input feedback, input communication).
As a result of the work, the following functions were derived:
1) Data collection - collection of information for analysis and decision making.
Enter arrow - assigning id;
Control arrows - rules, orders and leader;
Arrows of entry, control, mechanism are branching;
Arrow link at the entrance between jobs: Data collection and Data validation (records);
2) Data verification - verification of information and sending it to the preparation of a report.
Login arrow - assigning an id, entering data into the database;
Exit arrow - Report;
Control arrows - rules, orders and leader;
Mechanism Arrows - Employees, PC;
Arrows of entry (assignment of id), control, mechanism are forking;
Input feedback arrow from “Data Check” to “Data Acquisition” (repeated check).
DFD diagram description
In the decomposition of work "Computer maintenance" Figure 1, four internal work, two external entities and two data stores.
Figure 1 - Computer maintenance
1) Computer assembly - the process of assembling a computer from existing components.
2) Drawing up a report - a process that consists of summarizing the final indicators obtained by performing the work of the current accounting.
3) Diagnostics - performance check
4) Upgrade - improvement, improvement, upgrade of the computer.
External entities: computers and components
Data stores:
1) Warehouse - a place where assembled and upgraded computers are stored.
2) DB - a database that stores all reports and all information about the work done.
We collect information about the computer and select components for its assembly. Then we assemble the computer and send it to the warehouse for storage, but besides that, after assembling it, we can first send it for diagnostics, check for operability, and then only to the warehouse. After diagnosing the assembled computer, we send the data to compile a report on the work done and enter the information into the Database.
We also have another external entity, this is a computer. We send it for modernization, then for diagnostics to check its performance, then we draw up a report and enter information about the work done in the Database. Or, after the modernization, we send the goods to the warehouse, and then we carry out diagnostics, draw up a report and enter the information into the Database.
The work decomposition "Reporting" Figure 2 defines three internal activities, three external entities, and two data stores.
1) Data collection - collection of information about computers and components.
2) Validation - checking the data for accuracy.
3) Report - writing a report on the work done.
External entities: components, computers, manager.
Data warehouse - Data about computers and components, report data.
Collecting information about computers and accessories, then sending them for storage. After that, we check the data for accuracy, draw up a report and send it back for storage to the first data warehouse (Figure 2), or send the report data to the second data warehouse (Figure 2) and then send it to the manager for verification.
The manager checks, makes notes, corrections and sends for re-checking. After that, the report is sent for storage until the manager is re-checked.
Description of IDEF3 diagram
In the work decomposition Computer maintenance (Fig. 1), several intersections are defined that connect one or several jobs, several internal jobs.
1) Repair - assembling the computer with prefabricated components
2) Assembly - bringing the computer back to normal
3) Upgrade - computer upgrade
4) Computers - a product after assembly and modernization
5) Send to warehouse - send to storage after improvement (assembly)
6) Diagnostics - performance check.
7) Report - information about the work done.
Intersections - Connectors:
1) J2 - all actions start at the same time.
2) J6 - Confluence Junction. A node that collects many arrows into one, indicating the need for the condition of completing the work-sources of arrows to continue the process.
3) J7 - it is shown that these conditions cannot be simultaneously fulfilled.
4) J9 - these actions end at the same time after which a report on the work done is drawn up.
The IDEF3 diagram shows that the J2 junction has two branching arrows for work (build and upgrade) that start at the same time. Only after these works are completed, the finished product (computer) comes out, connects the J6 intersection. After that, there is a connection at the intersection J7, which shows that two jobs (sending goods to the warehouse and diagnostics) cannot be performed simultaneously. After completing the previous work, the process of drawing up a report on the work is underway, which is connected by the junction J9.
Objective:
- studying the basic principles of the IDEF0 methodology,
- creating a new project in BPWin,
- formation of a context diagram,
- making connections.
Describing a system using IDEF0 is called a functional model. The functional model is intended to describe existing business processes in which both natural and graphical languages are used. To convey information about a specific system, the source of the graphical language is the IDEF0 methodology itself.
IDEF0 methodology prescribes the construction of a hierarchical system of diagrams - single descriptions of system fragments. First, the system as a whole and its interaction with the outside world are described (context diagram), after which functional decomposition is carried out - the system is divided into subsystems and each subsystem is described separately (decomposition diagrams). Then each subsystem is broken down into smaller ones, and so on until the desired level of detail is achieved.
Each IDEF0-charts a contains blocks and arcs. The blocks represent the functions of the simulated system. Arcs link blocks together and represent the interactions and relationships between them.
Functional blocks (work) in diagrams are represented by rectangles representing named processes, functions, or tasks that occur over time and have recognizable results. The name of the job must be expressed by a verbal noun denoting an action.
IDEF0 requires a diagram to have at least three and no more than six blocks. These constraints maintain the complexity of diagrams and models at a level that is readable, understandable, and usable.
Each side of the block has a specific, well-defined purpose. The left side of the block is for inputs, the top is for control, the right is for outputs, and the bottom is for mechanisms. This designation reflects certain system principles: inputs are converted into outputs, control limits or prescribes the conditions for performing conversions, mechanisms show what and how a function performs.
Blocks in IDEF0 are arranged in order of importance, as the author of the diagram understands it. This relative order is called dominance. Dominance is understood as the influence that one block has on other blocks in the diagram. For example, the most dominant block of a diagram can be either the first of a required sequence of functions, or a planning or control function that affects all others.
The most dominant block is usually located in the upper left corner of the chart, and the least dominant in the right corner.
The arrangement of blocks on the page reflects the author's definition of dominance. Thus, the topology of the diagram shows which features have the greatest impact on the others. To emphasize this, the analyst can renumber the blocks according to their dominance order. Dominance order can be indicated by a number placed in the lower right corner of each rectangle: 1 will indicate the most dominance, 2 will indicate the next, etc.
The interaction of works with the outside world and among themselves is described in the form of arrows, depicted by single lines with arrows at the ends. Arrows represent some kind of information and are named with nouns.
Arrow types
IDEF0 distinguishes between five types of arrows.
entrance- objects used and transformed by work to obtain a result (output). It is assumed that the work may not have any entry arrows. The entry arrow is drawn as entering the left side of the work.
Control-. information governing the activities of the job. Typically, the control arrows carry information that indicates that the job is to be done. Each job must have at least one control arrow, which is depicted as entering the top face of the job.
Exit- the objects to which the inputs are converted. Each job must have at least one exit arrow, which is drawn as coming from the right edge of the job.
Mechanism- the resources that do the work. The arrow of the mechanism is drawn as entering the lower edge of the work. At the analyst's discretion, mechanism arrows may not appear on the model.
Call- a special arrow pointing to a different model of work. The call arrow is drawn as coming from the bottom of the work and is used to indicate that some work is being done outside the simulated system.
Rice. 2.1 Arrow types
In the IDEF0 methodology, only five types of interactions between blocks are required to describe their relationships: control, input, control feedback, input feedback, output-mechanism. The control and input links are the simplest because they reflect direct actions that are intuitive and very simple.
Rice. 2.2. Exit communication
Rice. 2.3. Management communication
A control relationship occurs when the output of one block directly affects the less dominant block.
Control feedback and input feedback are more complex because they are iteration or recursion. Namely, the outputs from one job affect the future performance of other jobs, which will subsequently affect the original job.
Management feedback occurs then; when the output of some block affects the block with a large dominance.
Exit-mechanism relationships are rare. They reflect a situation in which the output of one function becomes a means to an end for another.
Rice. 2.4. Input Feedback
Rice. 2.5. Management feedback
Exit-mechanism relationships are common in resource allocation (eg tools required, trained personnel, physical space, equipment, funding, materials).
In IDEF0, an arc rarely depicts a single object. It usually symbolizes a collection of objects. Since arcs represent collections of features, they can have multiple start points (sources) and end points (destinations). Therefore, arcs can branch out and connect. different ways... The entire arc or part of it can emerge from one or more blocks and end in one or more blocks.
Forking arcs, shown as diverging lines, means that all or part of the content of the arcs can appear in each branch. The arc is always tagged before the forking to give a name to the entire set. In addition, each branch of an arc can be marked or unmarked according to the following rules:
- unmarked branches contain the weight of the objects specified in the arc label before the branch;
- the branches marked after the bifurcation point contain all or part of the objects specified in the arc label before the bifurcation.
Merging arcs in IDEFO, depicted as lines converging together, indicates that the contents of each branch go to form a label for the arc resulting from the merging of the original arcs. After a merge, the resulting arc is always flagged to indicate a new set of features after the merge. In addition, each branch may or may not be flagged before being merged according to the following rules:
Rice. 2.6. Output-mechanism communication
- unmarked branches contain the weight of the objects specified in the shared label after the merge;
- branches marked before the merge contain all or some of the objects listed in the general mark after the merge,
Quantitative analysis of charts
To conduct a quantitative analysis of the diagrams, we list the model's indicators:
- the number of blocks in the diagram - N;
- chart decomposition level - L;
- balance diagram - V;
- the number of arrows connecting to the block - A
This set of factors applies to each diagram in the model. Recommendations for the desired values of the chart factors will be listed below.
It is necessary to strive to ensure that the number of blocks in the diagrams of lower levels would be lower than the number of blocks in the parent diagrams, that is, with an increase in the level of decomposition, the coefficient would decrease. Thus, the decrease in this coefficient suggests that. that as the model is decomposed, the functions should be simplified, therefore, the number of blocks should decrease.
Charts need to be balanced. This means that within the framework of one diagram, the situation depicted in Fig. 2.7: work 1 has significantly more incoming and control arrows than outgoing ones. It should be noted that this recommendation may not be followed in models describing production processes. For example, when describing an assembly procedure, a block may include many arrows describing the components of the product, and one arrow may go out - the finished product.
Rice. 2.7. An example of an unbalanced chart
Let's introduce the balance factor of the diagram
It is necessary to strive to Kh was minimal for the chart.
Apart from analysis graphic elements diagrams need to consider the names of the blocks. To evaluate the names, a dictionary of elementary (trivial) functions of the modeled system is compiled. In fact, functions of the lower, level of diagram decomposition should get into this dictionary. For example, for a database model, the functions “find a record”, “add a record to the database” can be elementary, while the function “user registration” requires further description.
After forming the vocabulary and compiling a package of system diagrams, it is necessary to consider the lower level of the model. If there are coincidences of the names of the blocks of diagrams and words from the dictionary on it, then this indicates that a sufficient level of decomposition has been achieved. The coefficient that quantitatively reflects this criterion can be written as L * C - the product of the model level by the number of matches of block names with words from the dictionary. The lower the level of the model (higher L), the more valuable the coincidences.
BPWin Toolkit
When BPWin is launched, the main toolbar, tool palette and Model Explorer appear by default.
When creating a new model, a dialog appears in which you should indicate whether the model will be created anew, or it will be opened from the ModelMart repository, enter the name of the model and select the methodology in which the model will be built (Fig. 2.8).
Figure 2.8 Model creation dialog
BPWin supports three methodologies - IDEF0, IDEF3 and DFD. In BPWin, it is possible to build mixed models, that is, a model can contain both IDEF0 and IDEF3 and DFD diagrams at the same time. The composition of the tool palette changes automatically when switching from one notation to another.
A model in BPWin is viewed as a collection of activities, each of which operates on a certain set of data. If you click on any object of the model with the left mouse button, a pop-up context menu appears, each item of which corresponds to the editor of a property of the object.
Example
Building a model of a system should begin with a study of all documents describing it. functionality... One of these documents is the terms of reference, namely the sections "Purpose of development", "Goals and objectives of the system" and " Functional characteristics systems ".
After studying the source documents and interviewing customers and users of the system, it is necessary to formulate the goal of modeling and determine the point of view on the model. Let us consider the technology of its construction using the example of the system "Employment Service within the University", the main capabilities of which were described in laboratory work No. 1.
Let us formulate the goal of modeling: to describe the functioning of the system, which would be understandable to its user, without going into details related to the implementation. We will build the model from the point of view of users (student, teacher, administrator, dean's office, company).
Let's start by building a contextual IDEF0 diagram - According to the description of the system, the main function is to serve its customers by processing requests from them. Thus, let us define the only work of the context diagram as "Serve the system client". Next, we define the input and output data, as well as mechanisms and controls.
In order to serve a client, it is necessary to register him in the system, open access to the database and process his request. The input data will be "client name", "client password", "source database", "client request". Execution of a query leads either to receiving information from the system, or to changing the content of the database (for example, when drawing up expert assessments), therefore, the output data will be "reports" and "modified database". The process of processing requests will be performed by the system monitor under the control of the administrator.
Context diagram
Thus, we define the context diagram of the system (Fig. 2.9).
Fig 2.9. System context diagram
Let's decompose the context diagram, describing the sequence of customer service:
- Determining the level of access to the system.
- Subsystem selection.
- Subsystem access.
- Changing the database (if necessary).
We get the diagram shown in Fig. 2.10.
After completing the decomposition of the context diagram, proceed to the decomposition of the next level diagram. Typically, when looking at the third and lower levels, the models go back to the parent diagrams and adjust them.
Rice. 2.10. Decomposition of the work "Service, client of the system"
We decompose all the blocks of the resulting diagram sequentially. The first step in determining the level of access to the system is to determine the category of the user. The client's name is searched in the user base, defining its category. According to a certain category, the authorization given to the user of the system is clarified. Next, the procedure for accessing the system is carried out, checking the access name and password. By combining information about the authority and the level of access to the system, a set of permitted actions is formed for the user. Thus, the definition of the level of access to the system will look as shown in Fig. 2.11.
Rice. 2.11. Decomposition of work "Determining the level of access to the system"
After going through the procedure for accessing the system, the monitor analyzes the client's request, choosing a subsystem that will process the request. Decomposition of the work “Addressing a Subsystem” does not correspond to the purpose and point of view of the model. The user of the system is not interested in the internal algorithms of its operation. In this case, it is important for him that the choice of the subsystem will be made automatically, without his intervention, therefore the decomposition of the call to the subsystem will only complicate the model.
Let's decompose the work "Client request processing" performed by the request processing subsystem, defining user categories and permissions. Before searching for an answer to a request, you must open the database (connect to it). In general, the database can be located on a remote server, so it may be necessary to establish a connection to it. Let's define the sequence of works:
- Opening the database.
- Executing the request.
- Generation of reports.
After opening the database, it is necessary to inform the system about the establishment of a connection with the database, then execute the request and generate reports for the user (Fig. 2.12).
It should be noted that the "Execution of a request" includes the work of various subsystems. For example, if the request includes testing, then it will be executed by a subsystem of professional and psychological tests. At the stage of query execution, it may be necessary to change the content of the database, for example, when drawing up expert assessments. Therefore, the diagram must provide for such a possibility.
Rice. 2.12.
Adjusting the chart
When analyzing the resulting diagram, the question arises, what are the rules for generating reports? It is necessary to have pre-formed templates, according to which the selection from the database will be made, and these templates must correspond to requests and must be predetermined. In addition, the client should be given the opportunity to choose the form of the report.
Let's correct the diagram by adding the arrows "Report templates" and "Requests to change the database" and the tunnel arrow "System client" to it. Tunneling of the "System Client" is applied in order not to place the arrow on the top diagram, since the function of selecting the report form is not important enough to display it on the parent diagram.
Changing the diagram will lead to the adjustment of all parent diagrams (Fig. 2.13 - 2.15).
It is advisable to decompose the work "Execution of a query" using the DFD diagram (laboratory work No. 3), since the IDEF0 methodology considers the system as a set of interrelated works, which poorly reflects information processing processes.
Rice. 2.13. Decomposition of work "Client request processing"
Rice. 2.14. Decomposition of the work "System client service" (option 2)
Rice. 2.15. System context diagram (option 2)
Let's move on to the decomposition of the last block "Database change". From the client's point of view, these systems are located in one database. There are actually six databases in the system:
- User database,
- DB of students, (option 2)
- DB of vacancies,
- Performance database,
- DB of tests,
- DB of expert assessments,
- DB summary.
According to the purpose of modeling, it is important for the client to understand that the received data is not immediately updated in the system, but goes through an additional stage of processing and control. The change algorithm can be formulated as follows:
- The database in which the information will change is determined.
- The operator forms a temporary data set and provides it to the administrator.
- The administrator controls the data and enters them into the database.
This model can be implemented in a different way, providing the ability to update the database directly on request, bypassing the data control process. In this case, it is necessary to ensure the integrity control of the database to avoid damage to it. In this case, the diagram will look like this (Fig. 2.17).
Rice. 2.16. Decomposition of work "Database change"
Rice. 2.17. Decomposition of work "Database change" (option 2) For the first option, shown in Fig. 2.12
Carrying out further decomposition of "Database Changes" will complicate the model, explaining how the physical change of the database in the system is carried out. In this case, the user will not receive any additional information on the work of the employment service system. It is advisable to decompose this work in the process of designing a database system at the stage of creating a logical database model.
Decomposition of the Query Execution work will be carried out in the next lab, illustrating the use of DFD diagrams to describe information processing processes.
We will carry out quantitative analysis models shown in fig. 2.12 and 2.13, according to the above procedure. Let us consider the behavior of the coefficient ^ for these models. The parent diagram "Client request processing" has a coefficient of 4/2 = 2, and a decomposition diagram is 3/3 = 1. The value of the coefficient decreases, which indicates a simplification of the description of functions with a decrease in the model level.
Consider the change in the coefficient K b in two model variants.
for the second option
Coefficient K b does not change its value, therefore, the balance of the diagram does not change.
We will assume that the level of decomposition of the considered diagrams is sufficient to reflect the purpose of modeling, and elementary functions (from the point of view of the user of the system) are used as titles of work on the diagrams of the lower Level.
Summing up the considered example, it is necessary to note the importance of considering several options for diagrams when modeling a system. Such variants may arise when adjusting diagrams, as was done with the "Processing a client request" or when creating alternative implementations of system functions (decomposition of the work "Modifying the database"). Consideration of options allows you to choose the best one and include it in the package of diagrams for further consideration.
Control questions
List Test questions:
- What is a model in IDEF0 notation?
- What do IDEF0 jobs mean?
- What is the order of naming works?
- How many jobs should be on one diagram?
- What is called a dominance order?
- How are the works arranged according to the principle of dominance?
- What is the purpose of the sides of the work rectangles in diagrams?
- List the types of arrows.
- What are the types of relationships.
- What are boundary arrows?
- Explain the naming convention for branching and merging arrows.
- What methodologies are supported by BPWin?
- List the main elements of the main BPWin window.
- Describe the process of creating a new model in BPWin.
- How to make a connection between works?
- How to set the name of the job.
- Describe the work breakdown process.
- How do I add work to a diagram?
- How to resolve tunneled arrows?
- Can a BPWin model contain diagrams of multiple methodologies?
Did you know,
what is a thought experiment, a gedanken experiment?
This is a non-existent practice, an otherworldly experience, the imagination of what is not in reality. Thought experiments are like waking dreams. They give birth to monsters. Unlike a physical experiment, which is an experimental test of hypotheses, a "thought experiment" trickeryly replaces experimental verification with desired, untested in practice conclusions, manipulating logical constructions that actually violate logic itself by using unproved premises as proven ones, that is, by substitution. Thus, the main task of applicants for "thought experiments" is to deceive the listener or reader by replacing a real physical experiment with his "doll" - fictitious reasoning on parole without physical verification itself.
Filling physics with imaginary, "thought experiments" led to the emergence of an absurd surreal, confused and confused picture of the world. A true researcher must distinguish such "candy wrappers" from real values.
Relativists and positivists argue that the "thought experiment" is a very useful tool for testing theories (also appearing in our minds) for consistency. In this they deceive people, since any verification can only be carried out by a source independent of the object of verification. The applicant of the hypothesis himself cannot be a test of his own statement, since the reason for this statement itself is the absence of contradictions in the statement visible to the applicant.
We see this on the example of SRT and GRT, which have turned into a kind of religion that governs science and public opinion... No amount of facts that contradict them can overcome Einstein's formula: "If a fact does not correspond to the theory, change the fact" (In another version, "- The fact does not correspond to the theory? - So much the worse for the fact").
The maximum that a "thought experiment" can claim is only the internal consistency of the hypothesis within the framework of the applicant's own, often by no means true, logic. This does not test the suitability of practice. This test can only take place in a valid physical experiment.
An experiment is an experiment in that it is not a refinement of thought, but a test of thought. A thought that is self-consistent within itself cannot verify itself. This is proven by Kurt Gödel.
Gennady Vernikov
At present, in Russia, interest in the generally accepted standards of management in the West has sharply increased, however, in real management practice, there is one very indicative moment. Many leaders can still be baffled by the direct question of organizational structure company or about the scheme of existing business processes. The most advanced managers who regularly read economic periodicals, as a rule, begin to draw hierarchical diagrams that are understandable only to them, but even in this process they usually quickly come to a dead end. The same applies to employees and managers of various services and functional units. In most cases, the only set of rules set out in accordance with which an enterprise must operate is a set of individual provisions and job descriptions... Most often, these documents were drawn up more than one year ago, are poorly structured and not interconnected and, as a result, simply gather dust on the shelves. For the time being, such an approach was justified, since during the formation of the Russian market economy, the concept of competition was practically absent, and there was no particular need to consider costs - the profit was gigantic. As a result of this, we have seen quite an understandable picture over the past two years: large companies that grew up in the early 90s, are gradually losing their positions, up to a complete withdrawal from the market. This is partly due to the fact that the enterprise did not implement management standards, the concept of a functional model of activity and mission was completely absent. With the help of modeling various areas of activity, it is possible to effectively analyze the "bottlenecks" in management and optimize the overall business scheme. But, as you know, at any enterprise, only those projects that directly bring profit are of the highest priority, therefore, it is usually only during a tangible crisis in the management of the company that we are talking about the survey of activities and its reorganization.
At the end of the 90s, when the market was sufficiently competitive and the profitability of enterprises began to fall sharply, managers felt enormous difficulties in trying to optimize costs so that products remained both profitable and competitive. Just at this moment, the need to have before your eyes a model of the enterprise's activity, which would reflect all the mechanisms and principles of the interconnection of various subsystems within the framework of one business, was clearly manifested.
The very concept of "modeling business processes" came into the everyday life of most analysts simultaneously with the appearance on the market of complex software products designed for integrated automation enterprise management. Such systems always imply a deep pre-project survey of the company's activities. The result of this survey is an expert opinion, in which individual paragraphs are made recommendations to eliminate "bottlenecks" in the management of activities. On the basis of this conclusion, immediately before the implementation of the automation system, the so-called reorganization of business processes is carried out, sometimes quite serious and painful for the company. This, and naturally, a team that has developed over the years is always difficult to force to "think in a new way". Such complex surveys of enterprises are always complex and significantly different from case to case tasks. There are well-tried methodologies and standards for solving such problems of modeling complex systems. These standards include the methodologies of the IDEF family. With their help, it is possible to effectively display and analyze the models of the activity of a wide range of complex systems in various sections. At the same time, the breadth and depth of examination of the processes in the system is determined by the developer himself, which allows not to overload the created model with unnecessary data. At the moment, the following standards can be attributed to the IDEF family:
IDEF0 is a functional modeling methodology. With the help of the visual graphical language IDEF0, the system under study appears to developers and analysts in the form of a set of interrelated functions (functional blocks - in terms of IDEF0). Typically, IDEF0 modeling is the first step in learning about any system;
IDEF1 is a methodology for modeling information flows within the system, which allows you to display and analyze their structure and relationships;
IDEF1X (IDEF1 Extended) is a methodology for building relational structures. IDEF1X is a type of Entity-Relationship (ER) methodology and is typically used to model relational databases relevant to the system in question;
IDEF2 is a methodology for dynamic modeling of systems evolution. Due to the very serious difficulties of analyzing dynamical systems, this standard was practically abandoned, and its development was suspended at the very initial stage. However, at present there are algorithms and their computer implementations that make it possible to transform a set of static IDEF0 diagrams into dynamic models based on "colored Petri nets" (CPN - Color Petri Nets);
IDEF3 is a methodology for documenting the processes occurring in the system, which is used, for example, in research technological processes at enterprises. IDEF3 describes the scenario and workflow for each process. IDEF3 has a direct relationship with the IDEF0 methodology - each function (functional block) can be represented as a separate process by means of IDEF3;
IDEF4 is a methodology for building object-oriented systems. IDEF4 tools allow you to visually display the structure of objects and the underlying principles of their interaction, thereby allowing you to analyze and optimize complex object-oriented systems;
IDEF5 is a methodology for the ontological study of complex systems. Using the IDEF5 methodology, the ontology of a system can be described using a specific vocabulary of terms and rules, on the basis of which reliable statements about the state of the system under consideration at a certain point in time can be formed. On the basis of these statements, conclusions about the further development of the system are formed and its optimization is carried out.
In this article, we will look at the most commonly used functional modeling methodology IDEF0.
The history of the IDEF0 standard
The IDEF0 methodology can be considered the next stage in the development of the well-known graphical language for describing functional systems SADT (Structured Analysis and Design Teqnique). Several years ago, a small edition of the book of the same name was published in Russia, which was devoted to describing the basic principles of constructing SADT diagrams. Historically, IDEF0 as a standard was developed in 1981 as part of an extensive industrial automation program called ICAM (Integrated Computer Aided Manufacturing) and was proposed by the US Air Force. The IDEF family of standards itself inherited its designation from the name of this program (IDEF = ICAM DEFinition). In the process of practical implementation, the participants of the ICAM program faced the need to develop new methods for analyzing interaction processes in industrial systems. At the same time, in addition to an improved set of functions for describing business processes, one of the requirements for the new standard was the availability of an effective methodology for interaction within the framework of the "analyst-specialist". In other words, the new method was supposed to provide group work on the creation of the model, with the direct participation of all analysts and specialists involved in the project.
As a result of the search for appropriate solutions, the IDEF0 functional modeling methodology was born. Since 1981, the IDEF0 standard has undergone several minor changes, mostly of a limiting nature, and its last revision was released in December 1993 by the US National Institute for Standards and Technology (NIST).
Basic elements and concepts of IDEF0
The graphical language IDEF0 is surprisingly simple and harmonious. The methodology is based on four main concepts.
The first is the concept of the Activity Box. A functional block is graphically depicted in the form of a rectangle (see Fig. 1) and personifies some specific function within the framework of the system under consideration. According to the requirements of the standard, the name of each functional block must be formulated in the verb mood (for example, "produce services", not "production of services").
Each of the four sides of a functional block has its own specific meaning (role), while:
Each functional block within the framework of a single considered system must have its own unique identification number.
Figure 1. Functional block.
The second "whale" of the IDEF0 methodology is the concept of an interface arc (Arrow). Also, interface arcs are often called streams or arrows. The interface arc displays a system element that is processed by a function block or otherwise affects the function displayed by this function block.
The graphical display of the interface arc is a unidirectional arrow. Each interface arc must have its own unique name (Arrow Label). As required by the standard, the name must be a noun turnover.
With the help of interface arcs, various objects are displayed that, to one degree or another, determine the processes taking place in the system. Such objects can be elements of the real world (parts, cars, employees, etc.) or streams of data and information (documents, data, instructions, etc.).
Depending on which of the sides this interface arc fits to, it is called "inbound", "outbound" or "control". In addition, only functional blocks can be the "source" (beginning) and "sink" (end) of each functional arc, while the "source" can only be the output side of the block, and the "sink" can be any of the three remaining ones.
It should be noted that any functional block, according to the requirements of the standard, must have at least one control interface arc and one outgoing one. This is understandable - each process must follow some rules (displayed by the control arc) and must produce some result (outgoing arc), otherwise it makes no sense to consider it.
When constructing IDEF0 - diagrams, it is important to correctly separate the incoming interface arcs from the control ones, which is often not easy. For example, figure 2 shows the function block "Process workpiece".
In a real process, the worker performing the processing is given a workpiece and technological instructions for processing (or safety rules when working with the machine). It may mistakenly seem that both the workpiece and the document with technological instructions are incoming objects, but this is not so. In fact, in this process, the workpiece is processed according to the rules reflected in the technological instructions, which should be respectively displayed by the control interface arc.
Figure 2.
It's another matter when technological instructions are processed by the chief technologist and changes are made to them (Fig. 3). In this case, they are displayed as an already incoming interface arc, and the control object is, for example, new industrial standards, based on which these changes are made.
Figure 3.
The above examples emphasize the seemingly similar nature of incoming and outgoing interface arcs, but there are always certain distinctions for systems of the same class. For example, in the case of considering enterprises and organizations, there are five main types of objects: material flows (parts, goods, raw materials, etc.), financial flows (cash and non-cash, investments, etc.), document flows (commercial, financial and organizational documents), information flows (information, intent, oral instructions, etc.) and resources (employees, machines, machines, etc.). At the same time, in various cases, all types of objects can be displayed by incoming and outgoing interface arcs, which control only those related to the flows of documents and information, and only resources can be displayed by arcs-mechanisms.
The obligatory presence of control interface arcs is one of the main differences of the IDEF0 standard from other methodologies of the DFD (Data Flow Diagram) and WFD (Work Flow Diagram) classes.
The third basic concept of the IDEF0 standard is Decomposition. The decomposition principle is used when breaking down a complex process into its constituent functions. In this case, the level of detail of the process is determined directly by the model developer.
Decomposition allows you to gradually and structured represent the system model in the form of a hierarchical structure of individual diagrams, which makes it less congested and easy to digest.
The IDEF0 model always starts with the presentation of the system as a whole - a single functional block with interface arcs extending beyond the considered area. Such a diagram with one functional block is called a context diagram, and is denoted by the identifier "A-0".
The explanatory text for the context diagram must indicate the Purpose of building the diagram in the form brief description and the point of view (Viewpoint) is fixed.
Defining and formalizing the development goal of IDEF0 - the model is extremely important point... In fact, the goal identifies the relevant areas in the system under study that should be focused on first. For example, if we model the activities of an enterprise with the aim of building further on the basis of this model information system, then this model will differ significantly from the one that we would develop for the same enterprise, but with the aim of optimizing supply chains.
The point of view defines the main direction of development of the model and the level of detail required. A clear fixation of the point of view allows you to unload the model, refusing to detail and study individual elements that are not necessary, based on the chosen point of view on the system. For example, the functional models of the same enterprise from the point of view of the chief technologist and the financial director will differ significantly in the direction of their detailing. This is due to the fact that, in the end, the CFO is not interested in the aspects of processing raw materials on production machines, and the chief technologist does not need drawn schemes of financial flows. The correct choice of point of view significantly reduces the time spent on building the final model.
In the process of decomposition, the functional block, which in the context diagram displays the system as a whole, is drilled in another diagram. The resulting second-level diagram contains functional blocks that display the main subfunctions of the functional block of the context diagram and is called a Child diagram in relation to it (each of the functional blocks belonging to a child diagram is respectively called a Child Box). In turn, the parent function block is called the parent block in relation to the child diagram (Parent Box), and the diagram to which it belongs is called the parent diagram (Parent Diagram). Each of the sub-functions of the child diagram can be further detailed by a similar decomposition of the corresponding functional block. It is important to note that in each case of decomposition of a functional block, all interface arcs included in this block or outgoing from it are fixed in the child diagram. This achieves the structural integrity of the IDEF0 model. The principle of decomposition is clearly shown in Figure 4. Attention should be paid to the relationship between the numbering of functional blocks and diagrams - each block has its own unique serial number on the diagram (the number in the lower right corner of the rectangle), and the symbol at the right corner indicates the number of the child diagram for this block. The absence of this designation means that there is no decomposition for this block.
There are often cases when individual interface arcs do not make sense to continue to be considered in child diagrams below a certain level in the hierarchy, or vice versa - individual arcs have no practical meaning above a certain level. For example, an interface arc depicting a "detail" at the entrance to the "Process on lathe"it makes no sense to reflect on diagrams at higher levels - it will only overload the diagrams and make them difficult to understand. On the other hand, it becomes necessary to get rid of separate" conceptual "interface arcs and not detail them deeper than a certain level. The IDEF0 standard provides for the concept of tunneling. The designation of the "tunnel" (Arrow Tunnel) in the form of two parentheses around the beginning of the interface arc means that this arc was not inherited from the functional parent block and appeared (from the "tunnel") only in this diagram. turn, the same designation around the end (arrows) of the interface arc in the immediate vicinity of the receiver block means that this arc will not be displayed and viewed in the child diagram of this block. interface arcs are not considered at some intermediate levels of the hierarchy - including In this case, they first "plunge into the tunnel" and then, if necessary, "return from the tunnel".
The final concept in IDEF0 is the Glossary. For each of the IDEF0 elements: diagrams, functional blocks, interface arcs, the existing standard implies the creation and maintenance of a set of relevant definitions, keywords, narratives, etc. that characterize the object displayed by this element. This set is called a glossary and is a description of the essence of this element. For example, for the "payment order" control interface arc, the glossary may contain a list of fields of the document corresponding to the arc, the required set of visas, etc. The glossary harmoniously complements the graphical language, providing the diagrams with the necessary additional information.
Figure 4. Decomposition of functional blocks.
The principles of limiting the complexity of IDEF0 diagrams
Typically, IDEF0 models carry complex and concentrated information, and in order to limit their congestion and make them readable, the corresponding complexity limits are adopted in the corresponding standard:
Limiting the number of functional blocks on the diagram to three to six. The upper limit (six) forces the designer to use hierarchies when describing complex items, and the lower limit (three) ensures that there is enough detail on the corresponding diagram to justify its creation;
Limiting the number of interface arcs suitable for one functional block (leaving one functional block) to four.
Of course, it is not at all necessary to strictly adhere to these restrictions, however, as experience shows, they are very practical in real work.
Discipline group work over the development of IDEF0-model
The IDEF0 standard contains a set of procedures that allow a large group of people from different areas of the modeled system to develop and agree on a model. Typically, the development process is iterative and consists of the following conditional stages:
Creation of a model by a group of specialists related to various areas of the enterprise. This group is called Authors in terms of IDEF0. Building an initial model is a dynamic process during which authors ask competent people about the structure of various processes. Based on the existing provisions, documents and survey results, a Model Draft of the model is created.
Distribution of the draft for review, approval and comments. At this stage, there is a discussion of the draft model with a wide range of competent persons (in terms of IDEF0-readers) in the enterprise. At the same time, each of the diagrams of the draft model is criticized and commented in writing, and then transferred to the author. The author, in turn, also agrees with the criticism in writing or rejects it outlining the logic of decision-making and returns the revised draft for further consideration. This cycle continues until the authors and readers come to a consensus.
Model approval. The approval of the agreed model occurs by the head of the working group in the event that the authors of the model and the readers do not have disagreements about its adequacy. The final model is a consistent view of the enterprise (system) from a given point of view and for a given purpose.
The visibility of the IDEF0 graphic language makes the model quite readable for persons who did not take part in the project of its creation, as well as effective for holding shows and presentations. In the future, on the basis of the constructed model, new projects can be organized aimed at making changes in the enterprise (in the system).
Features of the national practice of using functional modeling by means of IDEF0
V last years interest in the methodologies of the IDEF family is growing steadily in Russia. I constantly observe this, looking at the statistics of calls to my personal web page (http://www.vernikov.ru), which briefly describes the basic principles of these standards. At the same time, I would call interest in such standards as IDEF3-5 theoretical, and in IDEF0 quite practically justified. As a matter of fact, the first Case-tools allowing to build DFD and IDEF0 diagrams appeared on the Russian market back in 1996, simultaneously with the release of the popular book on the principles of modeling in the SADT standards.
Nevertheless, most executives still regard the practical application of modeling in IDEF standards as a tribute to fashion, rather than efficient way optimization the existing system business management. This is most likely due to a pronounced lack of information on practical application these methodologies and with the indispensable software bias of the absolute majority of publications.
It is no secret that almost all projects for the survey and analysis of financial and economic activity enterprises now in Russia are in one way or another related to the construction automated systems management. Due to this, the IDEF standards in the understanding of the majority have become conditionally inseparable from the implementation information technologies, although with their help it is sometimes possible to effectively solve even small local problems, literally with the help of a pencil and paper.
When conducting complex enterprise survey projects, the development of models in the IDEF0 standard allows you to visually and effectively display the entire mechanism of enterprise activity in the desired context. Most important, however, is the collaboration that IDEF0 provides. In my practical activities there were quite a few cases when the construction of the model was carried out with the direct assistance of employees of various departments. At the same time, the consultant explained to them the basic principles of IDEF0 in a fairly short time and taught them to work with the corresponding applied software... As a result, employees of various departments created IDEF diagrams of the activities of their functional unit, which were to answer the following questions:
What goes to the unit "at the entrance"?
What functions, and in what sequence, are performed within the unit?
Who is responsible for each of the functions?
What is the executor guided by when performing each of the functions?
What is the result of the unit's work (output)?
After agreeing on draft diagrams within each specific department, they are assembled by the consultant into a draft enterprise model, in which all input and output elements are linked. At this stage, all discrepancies of individual diagrams and their controversial places are recorded. Further, this model again passes through functional departments for further agreement and making the necessary adjustments. As a result, in a fairly short time and with the attraction of the minimum human resources on the part of a consulting company (and these resources, as you know, are very expensive), an IDEF0-model of an enterprise is obtained according to the "As is" principle, and, which is important, it represents the enterprise from the position of employees who work in it and thoroughly know all the nuances, including informal. In the future, this model will be transferred for analysis and processing to business analysts who will look for bottlenecks in company management and optimize the main processes, transforming the "As is" model into the corresponding "As should be" view. Based on these changes, a final conclusion is made, which contains recommendations for reorganizing the management system.
Of course, such an approach requires a number of organizational measures, primarily on the part of the management of the surveyed enterprise. This is due to the fact that this technique implies the assignment of additional responsibilities to some staff in the mastery and practical application of new methodologies. However, in the end, this pays off, since the additional one or two hours of work of individual employees over several days can significantly save money on the payment of consulting services to a third-party company (which in any case will tear away from the work of the same employees with questionnaires and questions). As for the employees of the enterprise themselves, in one way or another, I have not met any expressed opposition on their part.
The conclusion from all this can be done as follows: it is not at all necessary to come up with solutions for standard problems every time. Whenever you are faced with the need to analyze a particular functional system (from the spacecraft design system to the process of preparing a complex dinner), use the methods that have been tried and tested over the years. One of these methods is IDEF0, which allows you to solve complex life problems with the help of its simple and understandable tools.
