Planning
Build a construction schedule from a BOQ
Published:
Turn BOQ quantities into activities, durations and logic: WBS, productivity, calendars, the critical path and an XER file for Primavera P6.
Original guide. The productivity figure in the example is invented to show the method, not a norm. A qualified planner should review any programme before it becomes a baseline.
Why start from the BOQ
The BOQ already lists the work and its quantities. Grouping its items into activities gives a schedule whose durations trace back to quantities, which keeps progress measurement and cost loading consistent with the contract.
From BOQ items to activities
Structure first, then durations.
- Build a work breakdown structure (WBS) by area, level and trade.
- Group BOQ items that one crew carries out in one sequence into one activity.
- Keep the link from each activity to its BOQ items for cost loading and progress.
Durations from quantity and productivity
Duration = quantity ÷ (output per crew per day × number of crews). Record where every output figure comes from. Use the site’s working calendar: in Saudi Arabia the weekend is Friday and Saturday, and summer heat and Ramadan working hours each need their own productivity assumption.
480 m² ÷ (60 m² per crew-day × 2 crews) = 4 working days
Logic and the critical path
Link activities finish-to-start by default, and start-to-start with a lag where work overlaps. Avoid hard date constraints unless the contract imposes them. The critical path method (CPM) then shows which chain of activities sets the finish date, and how much float the others have.
Export and review
Primavera P6 imports XER files, the format many consultants and clients in the region ask for. Before the schedule becomes the baseline, review the calendar, the logic, the longest durations and the float.
- Every activity has a predecessor and a successor, apart from the start and finish milestones.
- No activity is driven only by a constraint.
- Every duration traces to a quantity and an output figure.