Schedule Planning and Critical Path Method
The 2026 PMP exam tests planning and managing the project schedule — from network diagrams and critical path in predictive to sprint velocity and iteration tracking in agile. Schedule management is among the most calculation-heavy areas on the PMP exam.
Activity Sequencing
Before scheduling, activities must be sequenced using dependency types:
- Finish-to-Start (FS) — B cannot start until A finishes. Most common dependency.
- Start-to-Start (SS) — B cannot start until A starts.
- Finish-to-Finish (FF) — B cannot finish until A finishes.
- Start-to-Finish (SF) — B cannot finish until A starts. Rarest dependency.
Dependency classifications:
- Mandatory (hard logic) — physically or contractually required
- Discretionary (soft logic) — preferred but not required; based on best practice
- External — involving outside parties (vendor delivery, regulatory approval)
- Internal — within the project team control
Leads and Lags:
- Lead — successor starts BEFORE predecessor finishes (overlap, acceleration)
- Lag — successor starts AFTER a delay from predecessor finish (waiting period)
Duration Estimating Techniques
- Analogous — uses historical data from similar projects. Quick but least accurate.
- Parametric — mathematical model (e.g., 0 per line of code x 10,000 lines). More accurate if data is reliable.
- Three-point (PERT) — Optimistic (O) + 4x Most Likely (M) + Pessimistic (P) / 6. Accounts for uncertainty.
- Bottom-up — estimates each work package then aggregates. Most accurate but most time-consuming.
Critical Path Method (CPM)
The critical path is the longest path through the network diagram. It determines the minimum project duration.
Key concepts:
- Critical path — zero total float. Any delay extends the project.
- Total float — time an activity can be delayed without delaying the project end date.
- Free float — time an activity can be delayed without delaying any successor.
- Forward pass — calculates early start (ES) and early finish (EF)
- Backward pass — calculates late start (LS) and late finish (LF)
- Float = LS - ES or LF - EF
Schedule Compression
Crashing — adding resources to critical path activities. Increases cost. Choose activities with least cost per time saved.
Fast-tracking — performing sequential activities in parallel. Increases risk. Only works with activities that can overlap.
Key differences:
- Crashing adds cost but not risk. Fast-tracking adds risk but not cost.
- Both only work on critical path activities.