Schedule Maintenance and Control
Maintaining the schedule
Schedule maintenance keeps the approved baseline and the current schedule trustworthy. The data date, or status date, separates actuals from forecast. Update only work that has occurred on or before the data date; record actual starts and finishes, remaining durations, and progress without rewriting history. Use a defined percent-complete method-duration, units, or physical-and apply it consistently. Out-of-sequence progress occurs when a successor starts before its predecessor finishes; resolve it explicitly rather than forcing dates.
Control and change
Control compares current forecast with the baseline, explains variance, and manages changes. Re-baselining is not routine progress updating; it requires formal approval and an audit trail. Preserve the original baseline, revision history, and schedule log. Look-ahead schedules should be short-horizon extracts from the current schedule, not independent plans.
Traps
Common errors include moving the data date backward, entering actuals after the status date, changing logic to make the schedule look better, and using percent complete without defining its basis. Another trap is treating a revised baseline as the original baseline.
Rule of thumb
Update to the data date, never beyond it. If an activity finished January 25 and the data date is January 31, record January 25 as the actual finish and zero remaining duration. If the forecast extends past the data date, leave it as forecast.
A maintained schedule is auditable: every change has a reason, a date, and an owner.