Schedule Contingencies

Planning schedule contingencies within a project can be used to mitigate some risks in a project.  This is especially true in large, complex projects with a lot of unknowns.

The following schedule contingencies could be considered:

  • understand the priority of deliverables and requirements and which  could be deferred or removed from scope (managing the triple constraints) without impacting project success criteria
  • add a block of time (buffer) before the expected completion of a deliverable, milestone, phase, iteration, or increment in the schedule.  This distributes the contingency across tasks and the resources responsible for those tasks.
    • a project buffer will protect the schedule if critical path tasks are delayed
    • feeder buffers protect from delays of non-critical path tasks that feed the critical path
  • add contingency to individual task estimates.  This is the least recommended alternative because
    • Parkinson's law states that people will take as long as you give them. Padding estimates can unnecessarily expand duration
    • padded estimates can be difficult to identify
    • padded estimates can compromise trust
    • extra time for individual tasks does not guarantee success