Early Start (ES) and Early Finish (EF) in project scheduling refer to, depending on dependencies and constraints, the earliest feasible times a task can start or finish. The shortest project length is found by computing these values in the Forward Pass in the Critical Path Method (CPM).
Key Components:
- Early Start (ES): The earliest time a task can begin without delaying the project.
- Early Finish (EF): The earliest time a task can be completed, assuming no delays.
- Formula for Calculation:
- ES of a task = EF of the previous task + 1 (if sequential)
- EF = ES + task duration – 1
Example in Scheduling:
If Task A (duration: 5 days) starts on Day 1, its EF is Day 5. If Task B depends on Task A’s completion, its ES is Day 6.
Why It Matters:
Knowing early start and early conclusion dates helps project managers best allocate resources, spot possible delays, and maximise scheduling.
