Projects are all unique, so planning more than a few months in advance with precision is difficult. Depending on the project type, reviews aligned with the planning horizon, every three to six months, allow necessary project plan development adjustments.
Weekly status collection, performance reporting, and integrated change control are all necessary, but on longer projects they are not sufficient. Periodic reviews provide the project equivalent of planned preventative maintenance.
Project reviews are most useful at natural project transitions:
Life-cycle or phase transitions
Major milestones or checkpoints
Following significant project changes
When new members are either added to or leaving project staff