Do you have a chance to draw an oversized BPMN workflow to model a complex problem? It is almost impossible to draw such a large BPMN by hand. Even if you want to draw it in software, if you want to put it on the display, the entire diagram will become too small. Or, if you just zoom in on a part of the diagram, there is no overall view of the workflow. This article will show you how to deal with structure your large BPMN into manageable parts.
There are two constructs in BPMN which can help us to manage large BPMN workflow:
Link Intermediate Evens
Link Intermediate Events are always used in pairs, with a source and a target Event. Informally, we also call them Link Events. To ensure the pairing, both the source and target Link Events must have the same label.
Activities are works that are performed within a business process. They are shown as rounded-rectangle, with names describing the works to perform.
There are two types of activities: Task and Sub-Process. When we want to model an atomic work that cannot be further broken down or makes no sense to do so, we use a task.
On the other hand, when we want to model a non-atomic, complex work that can be elaborated into smaller works, we use a sub-process. A sub-process can be broken down into another level of detail. For this reason, a sub-process usually contains another BPD modeling its details.
Note that the selection of task or sub-process is not just about how complex a work can be but also about how detailed you need to know about the work. If you are a customer, you probably don’t want to know how your payment is being processed. However, if you are in the shop, how to process customer’s payment becomes important.
In BPMN, a sub-process is a compound activity that represents a collection of other tasks and sub-processes. Generally, we create BPMN diagrams to communicate processes with others. To facilitate effective communications, we really do not want to make a business process diagram too complex. By using sub-processes, you can split a complex process into multiple levels, which allows you to focus on a particular area in a single process diagram.
If a process model extends beyond the length of one printed page you can use a Link Intermediate Event to show how Sequence Flow connections extend across the page breaks. Thus, Link Events can be used to show how Sequence Flow continues from one page to another called off-page connector.
In the BPMN diagram displays below, a segment of a process that can fit on one page as shown in the upper part of the Figure. The far-right side of the page has the first of a pair of Link Events that connects that segment of the Process to another segment of the Process on another page as shown in the lower part of the Figure below:
I believe you should be able to combine these two techniques appropriately to handle complex workflow in most of the case. In this way, you can have both the holistic view of a problem and at the same time, you can look into the details of it.