Forward Pass is a Critical Path Method (CPM) technique used to calculate the earliest possible start (ES) and early finish (EF) dates for activities by working forward through the schedule model from the project start date or a given point in time.
Key Aspects of Forward Pass
- Determines Earliest Start & Finish Dates – Identifies the soonest an activity can begin and end.
- Establishes the Project Duration – Helps define the minimum completion time.
- Identifies Critical Path Activities – Highlights tasks that drive project timelines.
- Works in Sequence from Start to Finish – Moves through the schedule from the first task to the last.
Forward Pass Formula
| Formula | Definition |
|---|---|
| ES = EF of predecessor + 1 | Early Start (ES) is the next available time unit after the predecessor’s Early Finish (EF). |
| EF = ES + Duration - 1 | Early Finish (EF) is calculated by adding the activity duration to ES. |
Example Calculation
Assume the following activities:
- Task A (Duration: 4 days)
- Task B (Duration: 3 days, depends on Task A)
- Task C (Duration: 5 days, depends on Task A)
| Task | Duration | Early Start (ES) | Early Finish (EF) |
|---|---|---|---|
| A | 4 days | 1 | 4 |
| B | 3 days | 5 | 7 |
| C | 5 days | 5 | 9 |
Mermaid Diagram: Forward Pass Calculation
graph LR; A["Task A (ES: 1, EF: 4)"] -->|Start at Day 5| B["Task B (ES: 5, EF: 7)"] A -->|Start at Day 5| C["Task C (ES: 5, EF: 9)"]
Why Forward Pass Matters
- Defines the Earliest Possible Completion Date – Essential for project planning.
- Identifies Critical Path Tasks – Determines which activities cannot be delayed.
- Supports Scheduling & Resource Allocation – Ensures tasks are planned efficiently.
- Improves Time Management – Helps teams meet deadlines with better visibility.
See also: Backward Pass, Critical Path Method (CPM), Schedule Network Diagram, Total Float.