Final answer:
The earliest start time for an activity is equal to the smallest of the earliest finish times for all its immediate predecessors.
Step-by-step explanation:
The given statement, 'The earliest start time for an activity is equal to the smallest of the earliest finish times for all its immediate predecessors,' is true.
This concept is known as the Forward Pass in project management, specifically in the Critical Path Method (CPM). The earliest start time (ES) for an activity is determined by finding the maximum earliest finish time (EF) among all the immediate predecessors of that activity.
For example, if Activity A has two immediate predecessors with EF values of 10 and 15, then the ES of Activity A will be 15.