Best Practices Checklist: Confirming That the Critical Path Is Valid

• The schedule’s critical path is valid. That is, the critical path or longest path (in the presence of constraints)
  • does not include LOE activities, summary activities, or other unusually long activities, except for future planning packages;
  • is a continuous path from the status date to the finish milestone;
  • does not include constraints that cause unimportant activities to drive a milestone date;
  • has no lags or leads;
  • is derived in summary schedules by vertical integration of lower-level detailed schedules, not by preselected activities that management has presupposed are important.
• If backward-pass date constraints are present on activities other than the finish milestone, both the critical path and the longest path have been identified. With a number of constraints, activities with zero or negative total float may outnumber activities that are actually driving the key program completion milestone.
• The critical path, or longest path (in the presence of constraints), is used as a tool for managing the program. That is, management has vetted and justified the current critical path as calculated by the software;
  • uses the critical path to focus on activities that will be detrimental to the key program milestones and deliveries if they slip;
  • examines and mitigates risk in activities on the critical path that can potentially delay key program deliveries and milestones;
  • has reviewed and analyzed near-critical paths because these activities are likely to overtake the existing critical path and drive the schedule;
  • recognizes not only activities with the lowest float but also activities that are truly driving the finish date of key milestones;
  • evaluates the critical path before the schedule is baselined and after every status update to ensure that it is valid.