BPMN Gateways are Often Misunderstood
BPMN Gateways are Often Misunderstood
Business Process Modelling Notation (BPMN) is a standardized set of symbols and rules that is used to create graphical representations of business processes. One type of symbol is the Gateway, which is used to control the flow of the process through the logic of decisions (comparable to a decision point in a traditional workflow). Students often have difficulty understanding what should be done when the process reaches a gateway, which is further complicated by the fact that there are several types of gateways each of which contains unique logic that affects the process path differently. There are several technology tools that support this notation and provide the library of symbols; however, students must understand in which situation to use a specific type of gateway given the rules associated with each type. Here are resources with information on the types of gateways in BPMN: Visual Paradigm: Types of Gateways in BPMN, Lucidchart: BPMN Gateway Types, Cammunda:BPMN 2.0 Symbol Reference.
I prepared an infographic (see file resource attached to this post) to support the following analogy:
Working with the Inclusive “OR” Gateway in BPMN – Let’s explore the logic of the Inclusive (OR) Gateway, where a token can take one or all outgoing paths. Consider that the tokens moving through our process are like a group of cars on a road, together following the single designated path, often encountering turns in the road, obstacles to navigate and signs to obey. Now imagine the group of cars reaching a fork in the road. The group of cars is forced to make a decision. They may continue down one road together as a group, or they may choose to split up and take whichever paths they want. It is possible for individual cars to be travelling down all roads simultaneously. Let’s imagine that the group splits in two and follows two out of three possible roads coming out of the fork. The two groups follow their respective roads, encountering a unique set of turns in the road, obstacles to navigate and signs to obey. The two groups reach the end of their roads and meet back together to continue on the road as a single group until they reach their destination. The group of cars must reach their final destination (end of the process) as they started, individual cars or multiple groups cannot arrive separately. Coming back to the token concept, the group of cars represents a single token. The token can be split (cloned) any number of times in the process as it reaches gateways (such as the Inclusive OR Gateway), however all tokens must be merged back together before reaching the end of the process.
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Example for "BPMN Gateways are Often Misunderstood":
https://bank.ecampusontario.ca/wp-content/uploads/2021/06/Infographic-Working-with-the-Inclusive-OR-Gateway.pdf
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