CPM Logic Relationships, Predecessor/Successor
The dependency links between activities in a critical path method schedule, defining which activities, predecessors, must happen before others, successors, can start or finish. These relationships are the actual logic that determines the [[concept-critical-path|critical path]], not just a list of dates.
Why it matters
Two activities that could genuinely overlap get treated as sequential purely because of how the logic relationship was set up, not because the real-world work actually requires it, and that single choice can stretch a schedule's calculated duration for no real reason.
On a real project
A scheduler links drywall installation to start only after all electrical rough-in is fully complete in every room, when the real-world sequence actually allows drywall to begin in rooms where rough-in is already done, a looser logic relationship that would shorten the schedule.
Who this matters most to
A Scheduler sets the logic relationships between activities, the actual decisions that determine which activities end up on the critical path.
Where this goes wrong
A scheduler links two activities with a simple finish-to-start relationship when the real-world logic actually allows them to overlap. That single choice artificially extends the schedule's calculated duration, making the project look further behind than the real site conditions actually require.
Explore next