Answer 1

A data structure that represents a particular instance of running of a process. It has associated context information that can be used and manipulated by the process. A process instance plays a role in a business process management suite (BPMS) that is very similar to but not exactly the same as a case in a case management system. A particular case may have more than one process instance associated with it.

Answer 2

The representation of a single enactment of a process. (See also general entry on
Instance).

Answer 3

A process diagram describes a generic sequence of events. An instance describes an actual process which includes data, real actions, and specific decisions. Workflow systems and simulation systems both keep track of the data from the execution of specific process instances in order to determine things like how long the process actually takes, who handled a specific instance or how much it cost. In the case of simulation systems, someone has to supply information about a set of actual instances.