When labor daily amount is not fixed, the most important thing is:
You must control by “Production Output” instead of only “Number of Workers”
Because construction labor changes every day:
Today = 12 workers
Tomorrow = 8 workers
Next week = 15 workers
So if you only look at worker count, the schedule becomes unclear.
The Correct Professional Method
Use This Formula:
Daily Productivity
=
Actual Work Completed
÷
Actual Labor Used
Example:
Wall plaster completed = 120 m²
Labor used = 6 workers
Then:
\text{Productivity} = \frac{120,m^2}{6,workers} = 20,m^2/worker
Now you know:
1 worker
=
20 m²/day
This becomes your REAL productivity data.
Why This Is Important
Because labor quantity changes every day.
But productivity gives you:
Real performance
Real forecasting
Real planning accuracy
Professional Construction Control System
Instead of Asking:
“How many workers today?”
Ask:
“How much work completed today?”
Real Site Example
Rebar Installation
| Day | Workers | Installed Rebar |
|---|---|---|
| Monday | 5 | 1 ton |
| Tuesday | 8 | 1.5 ton |
| Wednesday | 4 | 0.8 ton |
Now calculate productivity:
| Day | Productivity |
|---|---|
| Monday | 0.2 ton/worker |
| Tuesday | 0.187 ton/worker |
| Wednesday | 0.2 ton/worker |
Now you can clearly see:
Tuesday had more workers
But productivity became lower
That means:
More workers
does not always mean
better productivity
How Professionals Make Clarity
1. Use Quantity-Based Planning
Instead of:
10 workers for 5 days
Use:
500 m² plaster work
÷
20 m²/day/worker
=
25 worker-days
\text{Worker-Days} = \frac{500,m^2}{20,m^2/day/worker} = 25
Now the labor can flex:
| Workers | Duration |
|---|---|
| 5 workers | 5 days |
| 10 workers | 2.5 days |
This is much more accurate.
2. Use “Worker-Days” System
Professionals use:
Worker-Days
=
Workers × Days
\text{Worker-Days} = \text{Workers} \times \text{Days}
Example:
4 workers × 5 days = 20 worker-days
This helps compare different labor situations equally.
3. Use Daily Site Tracking
Every day track:
| Date | Task | Qty Done | Workers | Productivity |
|---|---|---|---|---|
| May 21 | Block Work | 80 m² | 4 | 20 m²/worker |
Now your data becomes measurable.
4. Use Baseline Productivity
Create company standard productivity.
Example for 8AM:
| Work Type | Standard Productivity |
|---|---|
| Plaster | 20 m²/worker/day |
| Block Work | 25 m²/worker/day |
| Painting | 35 m²/worker/day |
Then compare actual vs standard.
How to Use This in Microsoft Project
Microsoft Project works best when:
You estimate using:
Quantity
÷
Productivity
=
Duration
Example:
1000 m² painting
÷
50 m²/day
=
20 days
\text{Duration} = \frac{1000,m^2}{50,m^2/day} = 20,days
Then labor can increase or decrease later without destroying logic.
Most Important Construction Reality
Labor Count is Variable
Because workers may:
Come late
Leave early
Be absent
Move between zones
Work faster/slower
So labor count alone is unstable.
Quantity Output is More Reliable
Professional companies control by:
Output
+
Productivity
+
Worker-Days
NOT only:
Number of workers
Golden Rule
Labor quantity changes.
Productivity reveals truth.
And:
If you cannot measure output,
you cannot control schedule correctly.