Quantity tracking and physical progress
Last reviewed 9 September 20261,615 words7 min read
The spreadsheet underneath the percent
🟩 In one line: Every Physical % Complete for measured work should trace to a quantity sheet — BOQ quantity, installed this period, cumulative, percent — kept per activity or per zone, reconciled to inspection records, and stored where the next planner can find it, because a percent without a quantity behind it is an opinion.
👤 Who this is for: J/M. Read progress-measurement-and-rules-of-credit first; this page is the "units complete" method in practice.
First, let's be honest about why this page exists
Ask most planners where the 62% on the blockwork activity came from and they'll point at last month's sheet, which points at the month before, which points at a number the section engineer gave over the phone. Nobody can reproduce it. When the subcontractor disputes it, or the Engineer asks for substantiation, or a delay analyst needs to know when blockwork actually fell behind, there is nothing to show.
The quantity sheet is not sophisticated. It is one row per activity, five columns, updated monthly from documents that already exist on site. The difficulty is not building it — it is keeping it for three years.
🟨 The standard — what "good" looks like
| Source | What it says (paraphrased) |
|---|---|
| ANSI/EIA-748 — earned value techniques | Units complete is a discrete, objective measurement method: earned value = (units installed ÷ total units) × budget. Preferred over subjective percent wherever quantities exist. |
| PMI The Standard for Earned Value Management (2019) | Physical measurement methods must be traceable to documented quantities; the quantity basis is part of the performance measurement baseline. |
| AACE International RP 55R-09, Analyzing S-Curves | S-curves built from measured quantities are the reliable basis for trend and forecast; curves from assessed percent are not. |
| GAO Cost Estimating and Assessment Guide — EVM chapter | Progress should be supported by objective evidence retained for audit. |
| SCL Protocol, 2nd ed. — Part B, records | Contemporaneous progress records, including quantities installed, are the foundation of any later delay or disruption analysis. |
| FIDIC 1999 Cl 4.21 / 2017 Cl 4.20 | Monthly progress report to include quantities of work executed. |
| P6 Professional User Guide — Resources, Units; Percent Complete Types | Units % Complete = Actual Units ÷ (Actual + Remaining Units) when the activity carries a quantity resource. |
🟢 Rule: one quantity sheet per project, one row per measured activity, updated at every data date from signed site records, with the P6 Physical % Complete copied from it — never the other way round.
How it actually works
1. The sheet.
| Column | Source | Note |
|---|---|---|
| Activity ID and name | P6 | Match exactly; use the same zoning as the WBS |
| Unit | BOQ | m², m³, m, nr, t |
| Total quantity | BOQ or approved take-off | State which. If shop drawings change it, record the revision and date |
| Installed to last period | Previous sheet | Locked |
| Installed this period | Site records | Pour cards, delivery notes matched to install, IR sign-offs, daily reports |
| Cumulative installed | Sum | Formula |
| Physical % | Cumulative ÷ total | Formula; this is the number that goes into P6 |
| Evidence reference | Site records | IR number, pour card number, DN number |
| Remaining quantity | Total − cumulative | Feeds the remaining-duration check |
Keep it in one workbook, one tab per trade, protected against overwriting prior periods. Archive a copy at each data date alongside the XER.
2. What counts as installed. Installed means in place and accepted, or in place and inspection-requested where the rule of credit says so. It does not mean delivered, does not mean started, does not mean "the crew was on it". Blockwork is measured at the wall built; plaster at the area applied; cable at the length pulled and dressed, not the drums on site.
3. Zoning. Track quantities at the level the schedule is built. If plaster is one activity per level, the sheet has one row per level. If the schedule has one activity for all plaster on the tower, split it before you start — a single 40,000 m² activity that reads 38% tells nobody where the crew is. Zones should follow the WBS: floor, elevation, system, area.
4. Putting quantities in P6. Two options. (a) Enter the percent from the sheet into Physical % Complete manually — simple, works, common. (b) Load the quantity as a material or nonlabor resource on the activity: Budgeted Units = total quantity, update Actual Units each period, set Percent Complete Type = Units. P6 calculates the percent, the S-curve can be drawn by quantity, and Remaining Units is visible on the activity. Option (b) is better for repetitive trades and mandatory if the schedule is resource-loaded for EVM. Either way the sheet remains the audit record.
5. Reconciling to remaining duration. Remaining quantity ÷ achieved rate = the honest remaining duration. If 12,000 m² of blockwork remain and the crew has averaged 480 m²/day over the last three periods, remaining duration is 25 days — whatever the original duration said. See forecasting-honestly.
6. Three quantities that will not agree. BOQ quantity (what was priced), take-off quantity (what the drawings show), and installed quantity (what's built). Use take-off as the denominator once shop drawings are approved, note the BOQ figure, and expect the final installed figure to differ from both. The percent is against the current best estimate of total, revised with a note when the total changes.
🟥 Where people go wrong
- Counting delivered as installed. Forty drums of cable on site is stock, not progress. Measure what's pulled.
- One activity, one quantity, whole building. The sheet can't tell you which floor is behind. Zone it to the WBS.
- Overwriting last month's column. The trend is gone. Lock prior periods.
- Denominator drift without a note. The take-off grew from 9,000 to 10,400 m² and the percent fell — with no record why. Every change to the total gets a date and a reason.
- Sheet lives on one laptop. Three years, four planners. Put it on the project server, in the same folder structure as the XER archive.
- Copying P6 percent back into the sheet. The sheet is the source. If P6 disagrees, P6 is wrong.
⚖️ When you're challenged
"Substantiate the 62% on blockwork Level 7." Take-off 1,840 m² from shop drawing set A-BW-07 Rev 2; installed 1,140 m² per the daily reports and IR-BW-0712 to 0719, all signed by the consultant; 1,140 ÷ 1,840 is 62%. Sheet attached, evidence column references each IR.
"The subcontractor says 78% on the same wall." Their figure includes 300 m² delivered and stacked on L7 and a section built without an inspection request. Neither is installed under the subcontract rule. Their sheet and ours agree on the 1,140 built; the difference is definitional, not factual.
"Why did the total quantity change from last month?" Shop drawing Rev 2 added the plant-room blockwork on L7, 210 m². Total revised from 1,630 to 1,840, noted in the sheet on 14 May, and the percent recalculated. The installed quantity didn't change.
📄 Related pages
- Progress measurement and rules of credit — choosing units complete over the alternatives.
- Verifying subcontractor progress — comparing their quantities with yours.
- Forecasting honestly — remaining quantity ÷ achieved rate.
- Percent Complete Types — Units % Complete in P6.
- Resource Loading and Histograms — loading quantities as resources.
- S-Curves: Early, Late and Actual — drawing the curve from quantities.
- Notice Requirements and Records — the sheet as a contemporaneous record.
✏️ Worked example
A mid-rise in Dubai, plaster tracked by level. Update 06, data date 25 April 2025.
| Activity | Level | Unit | Total (take-off) | Installed to Upd 05 | Installed this period | Cumulative | Physical % | Evidence | Remaining qty |
|---|---|---|---|---|---|---|---|---|---|
| A3410 | L3 | m² | 2,150 | 2,150 | 0 | 2,150 | 100% | IR-PL-0301–0306 | 0 |
| A3420 | L4 | m² | 2,150 | 1,620 | 530 | 2,150 | 100% | IR-PL-0401–0407 | 0 |
| A3430 | L5 | m² | 2,180 | 410 | 1,090 | 1,500 | 69% | IR-PL-0501–0504 | 680 |
| A3440 | L6 | m² | 2,180 | 0 | 260 | 260 | 12% | IR-PL-0601 | 1,920 |
Achieved rate over Updates 04–06: 1,880 m² per period ≈ 78 m²/day on a 6-day, 24-day period. Remaining plaster L5 + L6 = 2,600 m² → about 33 working days with one crew, against 24 days in the baseline. The section engineer's remaining durations were revised to 9 days for L5 and 24 for L6; the narrative recorded a productivity shortfall of 20% against the SBM rate (97 m²/day) and the recovery plan added a second crew from L7.
Before the sheet existed (Updates 01–03), plaster percent had been reported as 15%, 30%, 45% — a straight line that matched the plan and not the site.
📖 References
- ANSI/EIA-748, Earned Value Management Systems — earned value techniques (check against your copy).
- PMI, The Standard for Earned Value Management (2019).
- AACE International RP 55R-09, Analyzing S-Curves.
- GAO-20-195G, Cost Estimating and Assessment Guide — EVM chapter (check against your copy).
- Society of Construction Law, Delay and Disruption Protocol, 2nd ed. (2017) — Part B, records.
- FIDIC 1999 Cl 4.21 / 2017 Cl 4.20 (check the edition in your contract).
- Oracle Primavera P6 Professional User Guide — Resources and Units; Percent Complete Types.
From the field
Experience from working planners. Unreviewed — read it as experience, not guidance.
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