Owner’s Rep Guide: Change Order Management
February 16, 2026
Principal Consultant
A construction schedule is only as good as its baseline. If the foundation is flawed, every update, forecast, and delay analysis that follows will be compromised. In my 30 years of reviewing Primavera P6 schedules for mega-projects like the Panama Canal and nuclear power plants, I consistently see the same logic errors repeated.
These errors don’t just mess up the dates—they expose the contractor to massive liability when claims arise. Here are the five most critical errors to avoid.
Every activity in a schedule (except the Project Start and Project Finish) must have at least one predecessor and one successor. “Open ends” disrupt the critical path calculation.
Lags are often used as a lazy way to create buffers or force dates. For example, putting a “Start-to-Start + 10 day lag” instead of modeling the actual workflow.
Instead of a lag, insert a tangible activity like “Concrete Cure Time” or “Submittal Review” so the time is accounted for transparency.
Using “Must Finish By” or “Start No Earlier Than” constraints hard-codes dates into P6, overriding the logic network. While sometimes necessary for contractual milestones, overuse freezes the schedule dynamic.
If you overuse constraints, the schedule stops reacting to progress updates, rendering the critical path meaningless.
Assigning a 7-day calendar to tasks that can only happen 5 days a week (or vice versa) creates artificial float. We often see “Cure Time” on a 5-day calendar (concrete cures on weekends too!) or “Government Review” on a 7-day calendar.
A schedule might look logically sound, but if it requires 500 pipefitters in Month 3 and you only have access to 200, the baseline is a fantasy. Resource leveling is the final sanity check that many planners skip.
Building a defensible baseline takes more than just connecting boxes in software. It requires understanding the construction means and methods. By avoiding these five errors, you protect your company’s interests and ensure your schedule is a useful management tool, not just a wall decoration.
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