Ask an estimator where a production rate came from and you will often get an honest shrug and a reference to how it has always been done. That is not incompetence. It is what happens when the data required to verify a rate only exists as a memory of how a job felt.
What a production rate is
A production rate is output per unit of input. The output is a physical quantity. The input is time, expressed in whatever unit is most useful to you:
| Basis | Example | Best for |
|---|---|---|
| Per crew-day | 800 CY per crew-day | Scheduling and daily targets |
| Per crew-hour | 80 CY per crew-hour | Comparing partial days and shift work |
| Per labor-hour (person-hour) | 16 CY per labor-hour | Comparing crews of different sizes |
| Unit cost | $6.50 per CY | Bidding and earned value |
They are the same fact in different clothes, and each one hides something. Crew-day rates hide crew size, so a 5-person crew and an 8-person crew look identical. Labor-hour rates hide equipment, which on earthwork is most of the cost. Unit cost hides both but is the only one that speaks directly to money. Track at least two.
Worked example
An excavation crew: 5 people, working 10-hour days, 5 days a week. That is 250 labor-hours and 5 crew-days per week. The estimate assumed 4,000 BCY per week at a cost budget of $6.50 per BCY.
Bid rate = 4,000 ÷ 250 = 16 BCY per labor-hour
After four weeks the crew has moved 13,000 BCY and the code has absorbed $97,000 in cost. Four weeks is 20 crew-days and 1,000 labor-hours.
Actual = 13,000 ÷ 1,000 = 13 BCY per labor-hour
Actual unit cost = 97,000 ÷ 13,000 = $7.46 per BCY
Rate attainment = 650 ÷ 800 = 0.81
The crew is running at about 81 percent of the bid rate and costing about 15 percent more per yard than budgeted. Those two numbers are not the same and should not be expected to match: production attainment is physical, unit cost includes crew composition and equipment cost. Where they diverge is informative. Here, 0.81 attainment against a 1.15 cost ratio suggests the shortfall is mostly production volume rather than an expensive crew.
These are the same numbers as earned value
Rate attainment of 0.81 is the SPI for this item, and the cost ratio of 1.15 is 1 ÷ CPI. That is not a coincidence. Earned value and production tracking are the financial and physical views of one underlying measurement. See CPI and SPI explained.
Why daily resolution matters more than accuracy
Contractors often chase precision when what they need is frequency. Consider a week:
| Day | Crew A (BCY) | Crew B (BCY) |
|---|---|---|
| Monday | 640 | 790 |
| Tuesday | 660 | 820 |
| Wednesday | 650 | 180 |
| Thursday | 645 | 810 |
| Friday | 655 | 650 |
| Week total | 3,250 | 3,250 |
Identical weekly totals. Completely different problems. Crew A has a rate problem: something structural is holding them 150 yards a day below the bid, and it will persist until somebody changes the method, the equipment, or the crew. Crew B is a capable crew that lost a Wednesday, and the entire management question is what happened Wednesday.
Weekly reporting cannot tell these apart. That is the argument for daily capture, and it is a stronger argument than any precision claim.
Recording conditions alongside the rate
A rate without context is not reusable. Two 650-yard days can mean opposite things. The conditions worth capturing alongside quantity are the ones that materially changed the rate:
- Material type and whether it differed from the geotech expectation
- Haul distance and route, which is one of the largest swing factors on earthwork
- Weather and ground moisture
- Crew size and composition, since a short crew is not a slow crew
- Equipment actually available, including breakdowns
- Interruptions: utility conflicts, inspection waits, access restrictions, other trades
The purpose is not documentation for its own sake. It is so that a year from now, when you are bidding similar work, you can filter your history down to the days that actually resemble the job you are pricing.
Turning history into a bid rate
- Collect completed work with quantity, hours, and conditions attached, at daily resolution.
- Filter to comparable conditions. Similar material, similar haul, similar crew and spread. A rate from a different situation is noise.
- Look at the distribution, not just the average. The mean tells you what to expect; the spread tells you what to carry as risk. A crew averaging 700 with a range of 650 to 750 is a very different bid than one averaging 700 with a range of 200 to 1,100.
- Decide where to bid within that distribution. Bidding the average means you miss half the time. Bidding the tenth percentile means you rarely win. That is a business decision, and the point of the data is to make it consciously.
- Close the loop. After the job, compare actual to bid, and feed it back. A rate library that is never corrected is just a slower version of guessing.
Most contractors bid rates they have never verified, then discover the truth at closeout. The data to fix that is generated every day and thrown away every day.
Where to go next
For the financial view of the same measurements, see what is earned value in construction and CPI and SPI explained. For earthwork-specific measurement issues, see earned value for dirt work.
PM Axsus captures installed quantity and the hours behind it against the same project and cost code, at the point of installation, which is what makes daily rate data exist at all. See production tracking.