IDEF0 charts are built using the BPWin program. They are intended for graphical modeling of ongoing business processes.
About IDEF0 Methodology
The IDEF0 methodology is widely used due to the simple and understandable graphical notation, the use of which is very convenient for building a model. The main place in the methodology is given to diagrams. The diagrams show the functions of the system through geometric rectangles, as well as the existing relationships between the functions and the environment. Links are displayed using arrows. You can verify this by seeing what IDEF0 offers, a diagram, examples of which can be found in this article.
The fact that only two graphic primitives are used in modeling allows us to quickly explain the current IDEF0 interaction rules to those people who have no idea about this type of diagram. Using IDEF0 diagrams, connecting a customer to ongoing processes is carried out more quickly thanks to the use of a visual graphics language. You can see what the IDEF0 chart offers, examples of which are presented below.
Elements used for IDEF0
As already mentioned, 2 types of geometric primitives are used: rectangles and arrows. Rectangles indicate specific processes, functions, work 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 indicate the material or information that will result in the output.
- Control. Regulatory, regulatory and management data that guides the process during its execution.
- Exit. Information or material that is the result of work that makes it possible to “theoretically” examine 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 do the job.
- Call. Part of the work that is being done outside the process.
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 take a look at IDEF0 (examples of diagrams made by other people).
- Any external environment of any system is described, even before final requirements are drawn up. In another way, the system and its environment can be modeled even before there are ideas about it and its embodiment.
Relationship Types between IDEF0 Processes
It is in the interest of the model to create such construction connections that internal connections are as strong as possible, and external ones are as weak as possible. This is the strength of modeling with IDEF0. You can see examples of diagrams yourself and see the truth of these words. To facilitate the establishment of connections, these are connected into modules. External connections are established between the modules, and internal connections are established inside the modules. There are several types of connections.
1. Hierarchical (“part” - “whole”) connection.
2. Manager (regulatory, subordinate):
1) direct communication management;
2) feedback management.
3. Functional or technological:
1) direct input;
2) reverse input.
3) consumer;
4) logical;
5) methodological or collegial;
6) resource;
7) informational;
8) temporary;
9) random.
Building blocks and relationships in diagrams
The IDEF0 methodology provides a number of rules and recommendations for its use and improvement of the quality of use. So, in the diagram one block is displayed, on which you can set the name of the system, its purpose. 2-5 arrows lead to or from the block. It is possible more or less, but at least two arrows are required for entry / exit, and the rest for additional work and their indications on the diagram. If the shooter is more than 5, you should think about the optimality of building the model, and is it possible to make it even more detailed.
Building blocks in decomposition diagrams
The number of blocks, which will be on one diagram, is recommended in the number of 3-6. If there are fewer, then such diagrams are unlikely to carry a semantic load. If the number of blocks is huge, then reading such a chart will be very difficult, given the presence of additional arrows. To improve the perception of information, it is recommended to place blocks from top to bottom and from left to right. This arrangement will reflect the logic of the execution of the sequence of processes. And also the arrows will create less confusion, having a 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 entry. But the presence of such a situation may speak to potential partners about a certain instability and the need to take a closer look at the potential partner.
The block, which has only an input arrow, indicates that the process receives input parameters, but control and adjustment during execution do not occur. A block that has only a control arrow is used to indicate operations that are called only by special order of the control system. They are managed and adjusted at all stages.
But an example of constructing an IDEF0 chart can convince that the most complete and encompassing type is a chart with input and control arrows.
Naming
To improve visual perception, each block and each arrow should have its own name, which will allow them to be identified among many other blocks and arrows. This is how diagram examples look in IDEF0. The information system built using them will help to understand all the shortcomings and complexities of the models.
Arrow merging is often used, and questions arise about their naming. But merging is possible only in the case of transferring homogeneous data, so separate names are not needed, although they can be specified in the BPWin program. Also, if there is a divergence of the arrows, then they can be separately named to understand what they are responsible for.
If there is no name after the branch, then the name is considered to be exactly the same as it was before the branch. So it can be if two blocks require the same information. The IDEF0 context diagram, an example of which can be found in this article, confirms these words.
Arrow Information
Arrows entering and leaving one block when constructing a composition diagram should be displayed on it. The names of geometric figures transferred to the diagram must exactly repeat the information of the highest level. If two arrows are parallel relative to each other’s arcs (i.e., they start on the edge of one process and end both on the same side of another process), then it’s possible to combine them and choose a suitable name to optimize the model, which is perfectly displayed in IDEF0 (examples of diagrams in Visio can be seen).
An example implementation of the IDEF0 methodology on a specific model
All information about the rules, recommendations and construction features would be rather poorly needed without practical examples of the implementation of the IDEF0 methodology.
You already learned what an IDEF0 diagram is, partially saw examples and rules for constructing such diagrams. Now we should turn to practice. For a better understanding, the explanation will go not on some “general” model, but on a specific example, which will allow to better and more fully understand the features of working with IDEF0 in the BPWin program.
An example will be the speed of a train from point A to point B. It must be taken into account that the train cannot reach a speed greater than the permissible one. This line is established on the basis of operating experience and the influence of trains on the railway. It should be understood that the purpose of the train is to deliver passengers, who, in turn, paid to safely and comfortably reach their destination. The IDEF0 chart is useful, examples of which can be found in this article.
Initial information are:
- data about the line of paths;
- passport of the entire distance;
- road plan.
Control data:
- Indication of the chief, head of the track service.
- Information about the existing flow of trains.
- Information about planned repairs, reconstructions, and changes to tracks.
The result of the model is:
- Speed limit with indication of the reason for the limit.
- Permissible speeds when driving at separate points and during the driving of trains.
When a context diagram is built, it must be detailed, and then a composite diagram is created, which will be the first level diagram. It will show all the basic functions of the system. The methodology and diagram IDEF0 for which decomposition is done is referred to as the parent. IDEF0 decomposition is called a child.
Conclusion
After decomposition at the first level, decomposition of the second level is carried out - and so on until further decomposition does not lose its meaning. All this is done to obtain the most detailed graphic diagram of the ongoing and planned processes. This is a ready-made example of an IDEF0 chart that you can navigate right now.