Level:
Intermediate
TCM Section(s)
7.2. Schedule Planning and Development
9.2. Progress and Performance Measurement
Venue: 2024 AACE International Conference & Expo
Abstract: Out-of-sequence logic occurs when actual status is applied to a planned CPM schedule.If the actual start date is earlier than the calculated early start date, then the actual date overrides logic.Depending on how the CPM calculation handles this occurrence, the remaining portion of the planned work may be delayed to re-enforce the planned logic.Studies show that approximately 40% of all started activities in typical construction projects are started out-of-sequence.
Most schedulers say that they ‘fix’ any out-of-sequence activity in schedule updates by modifying the activity or logic.This effort may be misinformed as many schedulers do not fully appreciate the number of out-of-sequence occurrences in their schedules.For example, P6 Professional software only reports on active, direct out-of-sequence activities.This is a small percentage of the actual out-of-sequence in a schedule.Besides, they may be fixing the wrong logic as the indirect out-of-sequence (which P6 Professional does not report) may be the correct activity to fix.This paper looks into the reasons, methods, and pitfalls involved in correcting out-of-sequence logic during updates. Definitive rules are proposed for various categories of out-of-sequence conditions presented in earlier papers.
TCM Section(s)
7.2. Schedule Planning and Development
9.2. Progress and Performance Measurement
Venue: 2024 AACE International Conference & Expo
Abstract: Out-of-sequence logic occurs when actual status is applied to a planned CPM schedule.If the actual start date is earlier than the calculated early start date, then the actual date overrides logic.Depending on how the CPM calculation handles this occurrence, the remaining portion of the planned work may be delayed to re-enforce the planned logic.Studies show that approximately 40% of all started activities in typical construction projects are started out-of-sequence.
Most schedulers say that they ‘fix’ any out-of-sequence activity in schedule updates by modifying the activity or logic.This effort may be misinformed as many schedulers do not fully appreciate the number of out-of-sequence occurrences in their schedules.For example, P6 Professional software only reports on active, direct out-of-sequence activities.This is a small percentage of the actual out-of-sequence in a schedule.Besides, they may be fixing the wrong logic as the indirect out-of-sequence (which P6 Professional does not report) may be the correct activity to fix.This paper looks into the reasons, methods, and pitfalls involved in correcting out-of-sequence logic during updates. Definitive rules are proposed for various categories of out-of-sequence conditions presented in earlier papers.