Guide to BPMN
BPMN 2.0 – Introductory guide:
Business Process Model and Notation (BPMN) is the leading standard for notation of business processes. An increasing number of organizations are using BPMN and universities bring BPMN into their lectures.
The reason behind the increased usage of BPMN is that is maintained by the Object Management Group (OMG) which means BPMN is supported by a wide range of vendors and has a very simple approach that makes it possible to start working with notation very quickly.
This BPMN introductory guide will give a better overview of the core elements and their purpose.
- Pools and Lanes
- Call activities
- Start events
- End events
- Intermediate events
- Sequence flow
- Message flow
Pools and lanes
Pool and Lanes will be essential for defining areas of responsibility and organizational boundaries. Pools and lanes are involved in defining these responsibilities within a business process. Pool is a unit of clear organizational boundaries, where lanes define the different responsibilities.
An example is given below, to give a better insight into how pools and lanes should be understood. The most common understanding of how a pool and the lanes work together will be to see the pool as a swimming pool, and the lanes as swimming lanes. The swimming lanes will typically represent the process participants that execute a process. This example will also show that lanes always exists in a pool.
To achieve an execution of a process there must be some action/work. This work will be defined as an activity. There are 3 types of activities that will be described further.
- Task: An activity that requires some steps to perform, or if the activity can’t be broken down to finer level of detail.
- Sub-process: To minimize the complexity of a process, sub-processes can be used. The sub-process is a compound activity that represents a collection of several of other tasks.
- Call-activity: An activity that is external to the current process definition. Allows to create a process definition that can be reused in multiple process definitions.
Gateways are used if a process have a point of decision. A process can have a decision point for executing and in that situation a gateway can be used. The exclusive gateway also called XOR gives an opportunity to have two different decisions in a process, where both results either have the same or different outcome.
Event are signals of something that happens within the process. For a process to start it requires a start event that trigger the beginning of a process. If a process ends it requires an end event that indicates that the business goal is achieved. Events can also have a changing impact in a process execution that is called intermediate event.
BPMN connects activities, events and gateways to each other with sequence flows and Message flows. These flows help express the order of execution.
There is given an example of both flows, to show how they work. The sequence flow only works in a single pool, where the message flow shows the interaction between different pools.
Now that there is a basic understanding of the core elements in BPMN 2.0, It will be much easier to map a process. This example of a process is online shopping and have all these core elements described.