IDEF0 diagram: examples and building rules

IDEF0 diagrams are built using the BPWin program. They are intended for graphic modeling of the ongoing business processes

About IDEF0 methodology

The IDEF0 methodology is widely used due to a simple and understandable graphical notation, the use of which for building a model is very convenient. The main place in the methodology is given to the diagrams. The diagrams show the system functions through geometric rectangles, as well as the existing connections between functions and the external environment. The links are displayed using the arrows. You can see this by seeing that the IDEF0 chart offers a diagram, examples of which can be found in this article.

The fact that only two graphic primitives are used in modeling allows you to quickly explain the current rules of IDEF0 interactions to people who have no idea about this kind of diagrams. Through the IDEF0 diagrams, the customer connects to the ongoing processes more quickly through the use of visual graphical language. You can see that IDEF0 offers a diagram, examples of which are presented below.

Elements used for IDEF0

As already mentioned, two types of geometric primitives are used: rectangles and arrows. Rectangles denote certain processes, functions, jobs or tasks that have goals and lead to the indicated result. The interaction of processes between themselves and the external environment is indicated by arrows. In IDEF0, there are 5 different types of arrows.

• Entrance. So designate the material or information that will result from the output.
• Control. Regulatory, regulatory and management data that guide the process during its execution.
• Exit. Information or material that is the result of the work, which makes it possible to "theoretically" inspect what the IDEF0 diagram shows. Examples of the implementation of various systems in such a model can be found in the public domain.
• Mechanism. Resources needed to perform the work.
• Call. Part of the work that is done outside the process.

The possibilities of using IDEF0

The IDEF0 methodology can be used to describe the functional aspect of any information system.

• Any system is described. To have an idea, you can look at IDEF0 (examples of diagrams that other people have done).
• Any external environment of any system is described, even before the final requirements are formulated. By a different system and its environment can be modeled even before there will be ideas about it and its embodiment.

Types of relationships between IDEF0 processes

It is in the interest of the model to create such links of constructions that internal communications are as strong as possible, and external ones - as weak as possible. This is the strength of modeling with IDEF0. Examples of diagrams you can see for yourself and verify the veracity of these words. To facilitate the establishment of connections, they are connected to modules. External modules are installed between modules, and internal modules are installed inside modules. There are several types of links.

1. Hierarchical ("part" - "whole") connection.

2. Managing (regulating, subordinate):

1) direct control communication;

2) control feedback.

3. Functional or technological:

1) the direct input;

2) reverse input.

3) consumer;

4) logical;

5) methodical or collegiate;

6) resource;

7) information;

8) temporary;

9) random.

Building blocks and relationships in diagrams

The IDEF0 methodology provides a number of rules and guidelines for its use and improvement in the quality of use. So, in the diagram one block on which it is possible to set the name of the system, its purpose is displayed. To the block or from the block leads 2-5 arrows. You can do more or less, but at least two arrows are required for entry / exit, and the rest for additional work and their instructions on the diagram. If the shooter is more than 5, you should think about the optimality of the model construction, and whether it is impossible to make it even more detailed.

Building Blocks in Decomposition Diagrams

The number of blocks that will be on one chart is recommended in the number of 3-6. If there are less, then such diagrams are unlikely to carry a semantic load. If the number of blocks is huge, then it will be very difficult to read such a diagram, given the presence of additional arrows. To improve the perception of information, it is recommended to place the blocks from top to bottom and from left to right. Such an arrangement will reflect the logic of execution of a sequence of processes. And also the arrows will create less confusion, possessing the minimum number of intersections with each other.

If the launch of a certain function is not controlled in any way, and the process can be started at any time, then this situation is indicated by the absence of arrows indicating control and input. But the presence of such a situation can tell potential partners about a certain instability and the need to take a closer look at the potential partner.

A block that has only an entry arrow indicates that the process receives input parameters, but control and correction at run time does not occur. A block that has only a control arrow is used to refer to works that are called up only by a special order of the control system. They are managed and adjusted at all their stages.

But the example of constructing the IDEF0 diagram can convince that the most complete and encompassing type is the diagram with the entry and control arrows.

Naming

To improve visual perception, each block and each arrow must have its own name, which will identify them among many other blocks and arrows. So look at the IDEF0 examples of diagrams. The information system built with the help of them will allow you to understand all the shortcomings and complexities of the models.

Often a fusion of arrows is used, and questions arise about their naming. But merge is possible only in the case of homogeneous data transfer, therefore some names are not needed, although they can be set in the BPWin program. Also, if there is a divergence of the arrows, then they can be separately named to understand what is responsible for.

If after branching there is no name, then it is considered that the name is exactly as it was before branching. So maybe if two blocks require the same information. Context diagram IDEF0, an example of which can be found in this article, will confirm these words.

Information about arrows

Arrows entering and exiting from one block when composing a composition diagram must be displayed on it. The names of the geometric figures transferred to the diagram should exactly repeat the information of the highest level. If two arrows are parallel to each other's arcs (that is, they begin on the edge of one process and end both on the same face of another process), then to optimize the model, they should be combined and the appropriate name selected, which is perfectly displayed in IDEF0 (examples of diagrams in Visio can be viewed).

Example of implementation of IDEF0 methodology on a specific model

All information about the rules, recommendations and design features would be rather weakly needed without bringing practical examples of the implementation of the IDEF0 methodology.

You have already learned that such an IDEF0 diagram, examples and rules for constructing such diagrams are partially seen. Now we should turn to practice. For a better understanding, the explanation will not be on some "general" model, but on a concrete example that will better understand the features of working with IDEF0 in the BPWin program.

As an example, the speed of the train will move from point A to point B. It is necessary to take into account that the train can not develop the speed more taken for permissible. This boundary is established on the basis of operating experience and the influence of trains on the railway track. It should be understood that the purpose of the train is to deliver passengers who, in turn, have paid to safely and comfortably reach their destination. The IDEF0 diagram is useful, examples of which can be found in this article.

The initial information is:

1. Data about the track line;
2. Passport of the whole distance;
3. Road map.

Control data:

1. The instruction of the chief, the head of the track service.
2. Information about the existing flow of movement of trains.
3. Information about the planned repairs, reconstruction and modification of ways.

The result of the model is:

1. Limitation of permissible speeds with indication of the reason for the restriction.
2. Permissible speeds when driving at separate points and during the movement of trains.

When a context diagram is built, it must be detailed, and then a composite chart is created, which will be a first-level diagram. It will show all the main functions of the system. The methodology and IDEF0 diagram for which decomposition is done is called the parent. IDEF0 decomposition is called a child.

Conclusion

After decomposition at the first level, the second level is decomposed - and so on until further decomposition loses its meaning. All this is done to obtain the most detailed graphic scheme of the current and planned processes. This is a ready-made example of an IDEF0 chart, on which you can navigate now.