- Watch out
- What it costs
- Experienced readers
- Remember
- In BIMpedia
Every week, project controls ask: are we where we planned to be? and what does it cost? Usually the answers come from percentages someone estimates in a spreadsheet. With the programme linked to the model and quantities priced, the model can answer both, element by element, zone by zone.
The frame package reports "90% complete" for six weeks running. The figure is a foreman's estimate. When the planner finally walks the floors, three zones still have beams missing and the slab pours are a fortnight late.
Each week the site engineer marks finished zones on the tablet, which sets actual dates on the linked activities. The 4D model shows planned against actual: zone B frame is late, 54 elements. The cost report uses the same elements, priced from the take-off, so the late work has a value too.
Three numbers
| Measure | Question | From the model |
|---|---|---|
| Planned value (PV) | What should be done by now, at its budget? | Elements planned by the status date × their cost |
| Earned value (EV) | What is done, at its budget? | Elements built × their cost |
| Actual cost (AC) | What did the done work cost? | From the cost system |
If EV is below PV, the job is behind; if AC is above EV, the work done cost more than budgeted.
The status date is the date up to which actual progress is recorded. Plans compared against it show what's late. On BIMpedia, the 4D Simulator's "Planned vs actual" view colours late work red at the status date.
Open the 4D Simulator on the sample. Choose Planned vs actual; the status date is 5 April 2027.
- How many elements are late, and in which activities?
- Using the cash flow in Quantity Take-off and 5D on the sample, roughly how much planned spend falls in the weeks up to the status date?
- Write a three-line status for the project manager.
Key takeaways
- Progress measured on elements (built or not, by zone) is more objective than a percentage someone estimates.
- Planned value, earned value and actual cost compare what should be done, what is done, and what it cost.
- The 4D model shows the planned state on any date; actual dates show where the job really is.
- Report by zone and package, with the two or three numbers that lead to decisions.
Your notes
Related tool
Play the programme on the IFC model: see it built day by day, find late work and sequence errors.
Open 4D Simulator →