Why weighted progress?
A simple average of activity percentages treats a one-day inspection the same as a three-month piping campaign. Weighted progress gives each activity a weight in proportion to its size, normally its budgeted man-hours, so the overall figure reflects how much of the work is really done.
The three formulas
- Activity percent complete = quantity done ÷ scope quantity. For example, 450 of 1,200 inch-dia welded is 37.5%.
- Activity weight = activity budget man-hours ÷ total budget man-hours.
- Overall progress = Σ (weight × activity percent complete), which is the same as earned man-hours ÷ total budget man-hours.
Worked example
| Activity | Budget MH | Weight | Scope | Done | % complete | Earned MH |
|---|---|---|---|---|---|---|
| Steel erection | 2,000 | 20% | 100 t | 100 t | 100% | 2,000 |
| Piping welding | 5,000 | 50% | 4,000 in-dia | 1,600 in-dia | 40% | 2,000 |
| Cable pulling | 2,500 | 25% | 10,000 m | 1,000 m | 10% | 250 |
| Loop checks | 500 | 5% | 200 loops | 0 | 0% | 0 |
| Total | 10,000 | 100% | 4,250 |
Overall progress is 4,250 ÷ 10,000 = 42.5%. A simple average of the four percentages would have said 37.5%, understating the work done because the finished steel is a big share of the job.
Planned progress and the S-curve
Planned progress uses the same weights, but with each activity's planned percent complete at a date, found by spreading its man-hours over its planned duration. Adding these up week by week gives the planned cumulative curve, which is usually S-shaped: slow during mobilisation, steep during peak construction, flattening during commissioning.
Plot actual cumulative progress on the same chart. If the actual line sits below the plan, the project is behind; the vertical gap is the progress variance and the horizontal gap is roughly the time behind schedule. Planline draws planned, baseline and actual curves automatically on the dashboard and in the Excel report.
Recording progress by period
The Progress entry sheet in Planline lets you enter quantities done per day, week or month. It keeps the cumulative quantity for each activity and shows period progress, cumulative actual and cumulative planned for the whole project, which is what most monthly progress reports need.
Common pitfalls
- Changing weights mid-project without re-baselining makes the curve jump. Freeze the weights with the baseline.
- Using duration as weight overweights long, light activities such as procurement lead times.
- Mixing units: keep a consistent unit per activity (inch-dia, tonnes, metres) and agree it with the client's progress measurement procedure.
- Rules of credit: many contracts give partial credit by step (for example 30% on fit-up, 70% on welding). Split those activities or record the credited quantity.
Frequently asked questions
How is activity weightage calculated?
Usually as the activity budget man-hours divided by the total budget man-hours of the project or package. Cost can be used instead, but man-hours is the norm for construction progress.
What is the difference between physical progress and earned value?
Physical progress is earned man-hours divided by total budget man-hours. Earned value applies the same idea to cost and compares it with planned value and actual cost.
Why is my S-curve not S-shaped?
Short projects, front-loaded weights, or activities with very uneven man-hours can flatten or skew the curve. That is fine; the comparison with actual progress is what matters.
Try it on your own schedule
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