Reviewing a baseline schedule before you accept it
Thursday afternoon, the office scheduler sends the baseline for a four-storey wood-frame affordable housing building: 212 activities, finishing exactly on the contract date. It goes to the owner on Monday, and once it is accepted, every update and request for more time will be measured against it.
Before you accept a baseline, check that all the work is in it, that every activity is tied into the logic, that the longest durations come from real quantities, and that logic, not constraints, holds the dates. Baselines are often built fast, from a template or the last job, and are easy to accept when the finish matches the contract. Acceptance does not make them right: Indiana's transportation department, for one, says its acceptance does not validate the contractor's logic or durations, and that work left out of the schedule must still be finished on time.
- Read it against the contract: completion and interim dates, phases and access dates, each shown as a milestone or an activity.
- Look for missing work with the specifications' table of contents: submittals and reviews, long-lead deliveries, inspections, utility connections, commissioning, and the owner's and consultant's activities.
- Find the open ends: activities with no predecessor or successor, or whose only link onward is start-to-start or only link in is finish-to-finish. At an open end, a slip moves nothing that it should.
- Test the ten longest durations with durations from quantities, and split long ones. Check the owner's limit: Indiana uses 20 activity calendar days unless approved; the Corps' guide uses 20 workdays or 30 calendar days for non-procurement activities.
- Ask what every constraint and lag is for; Indiana requires a written reason for each.
- Walk the critical path with the foremen, and question big float: months of it usually means a missing successor.
- Send one written list of comments before acceptance: activity ID, problem, proposed fix.
Common mistakes
- Checking the finish date and nothing else.
- Accepting durations copied from a job with different quantities.
- Raising problems by phone, with no record of what you flagged.
Checking a general contractor's schedule for your own trade is a narrower job; see the trade's side.
Checklist
Before you accept the baseline
- Contract dates, phases and access dates shown
- Reviews, deliveries and inspections included
- Work by the owner and utilities included
- Only the first and last activities open-ended
- Longest durations checked against quantities
- A reason for every constraint and lag
- Comments sent in writing
Check your understanding
The draft baseline shows the sprinkler rough-in with 60 working days of total float. What does that suggest?
