What is simple word for "process instance"?

Solution 1:

Procedure: (dictionary.com)

1. an act or a manner of proceeding in any action or process; conduct.

2.a particular course or mode of action.

Procedure

A fixed, step-by-step sequence of activities or course of action (with definite start and end points) that must be followed in the same order to correctly perform a task. Repetitive procedures are called routines.