What is a Process Instance?

A process instance (also called a "case") is the concrete, one-time execution of a process – for example, a single customer order running through the entire order-to-cash process. It comprises all events belonging to that one case.

Why does this matter?

The process instance is the fundamental unit of analysis in Process Mining. Only by bundling events into instances can throughput times, variants, and deviations be measured and compared.

What does this look like in practice?

Order 4711 is one instance of the order-to-cash process: created 2 March, credit-checked the same day, delivered 5 March, paid 28 March. Every event carrying that case ID belongs to it — and the 26-day cycle time is that of this one instance, not of the process as a whole.

Not to be confused with

Not to be confused with a process variant: many instances can share the same path and together form one variant. Nor with the process model, which describes every possible run, whereas the instance is exactly one run that happened.