LEARN. PRACTICE. GROW.Effort is not duration
Ten person-days assigned to someone available at 25% require about forty working days before other constraints. Account for leave, recurring work, incidents, and external dependencies. The plan should make its assumptions explicit.
Tailor the approach
A fixed deadline can coexist with iterative delivery. For example, maintain governance milestones for a migration and build automation in small increments. Include testing, monitoring, rollback, and operational handover in the scope from the start.
Guided application
Draw deliverables, activities, and predecessors before promising dates. In the example A=2, B=6 and C=4 in parallel, D=3 after both, minimum duration is 11 days under the stated assumptions. Shortening C does not change completion while B dominates. Adding people only helps when parallelizable work, skills, access, and integration time exist. A hybrid approach may retain architecture approvals and production windows while developing automation incrementally. Each increment needs quality and feedback; flexibility does not remove dependencies, budget, or acceptance. Include recovery and retirement to avoid transferring invisible work to operations.
Forecast after an impediment
When a task stops because access is missing, update actual progress and obtain a grounded remaining-work estimate. Recalculate dependencies and capacity before promising a date. A desired date may justify examining recovery but does not authorize arbitrarily reducing durations or changing the historical start. Keep the approved baseline, current forecast, and response options separate so the committee understands variance and the needed decision.
Usable capacity and plan uncertainty
Total available days can hide the capability that constrains delivery. In an exercise with eight Linux days and four Oracle days, a requirement of six in each area leaves two Oracle days uncovered despite twelve days overall. Also check continuity: four average free hours do not guarantee a four-hour block for an on-call specialist. Cross-check the schedule against environments, access, operational coverage, and external commitments. If a pilot determines a later phase, represent that phase with assumptions and a planned review rather than invented detailed tasks. Three duration estimates help expose uncertainty; without a model, dependencies, and assumptions, they do not establish a probability of completing the project on an exact date.
A firewall change needs five working days and a shared team. Record that dependency before scheduling the external partner test.
Common pitfalls
Doubling capacity on paper; shortening an activity without checking the constraining path.
Related topics: Risk, change, and informed decisions · Measure value and hand over autonomy
A credible plan connects work to real availability and dependencies.
Reference: Schedule Assessment Guide · PMP ECO July 2026; DR PMP 2026.5