Introduction
At the heart of just about any information system developed for organizations, there is a business process. A business process is a standard method for accomplishing a partic‐ ular task necessary for an organization to function. A business process can come from any business function, from accounting to supply chain management to after-sales ser‐ vice. It can cross business functions as well. A business process can be simple or com‐ plex, but the more complex it is, the harder it is to automate. Complexity also makes a process more difficult to understand for those who are not familiar with it. Communica‐ tion tools are needed to describe business processes to those who need to know about them, such as systems analysts, but who have no firsthand knowledge of the process‐ es. There are many ways to represent business processes, from data flow diagrams to activity diagrams. The Object Management Group (OMG), the same group that is re‐ sponsible for standards for object-oriented programming, has established a specific modeling approach for business processes. It is called Business Process Modeling No‐ tation (BPMN). This appendix provides a very brief introduction to BPMN. First, we will introduce you to the basic notation in BPMN, and second, we will provide a couple of examples. If you are interested in mastering BPMN, there are many materials available (see the reference list).
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Basic Notation
Business Process Modeling Notation is much more complicated than data flow diagrams notation; it is made up of many more symbols, and each symbol has numerous variations. (The interested reader is referred to the BPMN standards and numerous other documents to learn about all of the various as‐ pects of the complete BPMN standard. See the reference list at the end of the appendix.) However, there are four basic concepts in BPMN, each of which has its own basic symbol. These basic concepts are events, activities, gateways, and flows. Their symbols are as follows:
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All business processes begin and end with an event . The symbol for an event is a circle. For a start‐ ing event, the walls of the circle are thin. For the ending event, the walls are thicker. A starting event can be colored green, and an ending event can be colored red. An activity is some action that must take place for the process to be completed. An activity can be completed by people or by a computerized system. The symbol for an activity is a rectangle with rounded edges. A gateway , symbolized by a diamond, is a decision point. The final primary concept is flow , represented by an arrow. Flow shows sequence, the order in which activities occur. A simple example, without content, of a process represented by BPMN, is as follows:
Event
In business process modeling, a trigger that initiates the start of a process.
Activity
In business process modeling, an action that must take place for a process to be completed.
Gateway
In business process modeling, a decision point.
Flow
In business process modeling, it shows the sequence of action in a process.
In this simple example, you see that the business process starts with some event, shown with an event symbol on the left. BPMN diagrams are always read from left to right. The event is followed by the first activity. An arrow symbolizing flow connects the event to the activity. The first activity is followed by a gateway. This is a decision point, indicated by two choices: “Yes” and “No.” Some condition is associ‐ ated with the gateway, and that condition can either be met (Yes) or not (No). Whether the condition is met or not determines where the flow goes next in the diagram. Both conditions lead to an additional activity. If the flow goes through the top of the diagram, there is one more activity that takes place be‐ fore the process ends at its ending event. If the flow goes through the bottom part of the diagram, the
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process concludes after just one activity is completed. Note how the walls of the circle that represents the final event are much thicker than those of the circle representing the beginning event.