The Secret to Equivalence Partitioning: Think About Outputs First
Equivalence Partitioning - Part 3
The method for equivalence partitioning will usually begin with the specification document, where one exists. It can also be derived from your understanding of how the system should behave under different conditions.
The essence of equivalence partitioning is in grouping behaviours of a system. In other words, look at the different expected output partitions first, then consider the input partitions to achieve each output.
As an example, let us consider a Team's meeting at work. What might your collective expected (and observable) behaviours be?
Examples:
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To access the meeting, you will all click on the Team's link provided.
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You will all go for breaks at the same time.
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You will have lunch at the same time.
This collective behaviour will make you an equivalence partition. If one of you is out for a break, it is expected that you are all on a break. Items 1-3 above are the output partitions.
On the input side, the partitions will be:
A1. The Team's link – a discrete partition, unique to that meeting.
A2. Perhaps a break - maybe between 10:15 and 10:30 for 15 minutes – a finite partition.
A3. Hopefully time for lunch! - maybe between 12:30 and 12:45 for 45 minutes – as above, a finite partition.