Normally, the Man to Machine Ratio (MMR) is calculated considering a single shift. Though sometimes factories work overtime for 2-4 hours a day, I have never seen or heard of factories deriving the Man-to-Machine Ratio differently for overtime hours.
I think this question is an eye-opener for engineers and production teams to think differently about how to calculate MMR for a factory.
Check out our digital swatch cards here
How Are Working Hours Considered in Productivity?
When calculating machine productivity, you need to consider the working hours per shift. Factories usually define their productivity based on units produced during an 8-hour shift or a 10-hour shift.
Factories sometimes convert overtime hours into manpower, where 8 hours of work are considered equal to one manpower.
This approach works reasonably well when you are dealing with a single-shift operation. But what happens when the same machines are being used for two different shifts?
What Happens When a Factory Works Two Shifts?
Normally, garment factories don’t work double shifts. However, it is common for textile mills and processing houses to operate for 24 hours using three shifts a day.
A double shift means that the same set of sewing machines and equipment is utilized by two different shifts during the same day.
How Should MMR Be Calculated for a Double Shift?
We have never calculated the Man-to-Machine Ratio for a double-shift plant before. Since we received this question, we are sharing our views on how MMR should be calculated when a factory operates two shifts.
When machines are utilized for two shifts, the machines should be counted twice when calculating the Man-to-Machine Ratio.
Otherwise, if we count the machines only once but include the total manpower from both shifts, the resulting MMR will be close to double the actual ratio. In my opinion, this would give an incorrect presentation of the factory’s Man to Machine Ratio.
Formula for Man to Machine Ratio in Two Shifts
To make the MMR more realistic, I would suggest using the following formula when a factory works two shifts in a day:
Man to Machine Ratio = (Total manpower of Shift 1 + Total manpower of Shift 2) / (Total machines utilized in Shift 1 + Total machines utilized in Shift 2)
For example, if the factory has manpower and machines working across two separate shifts, both the manpower and the machines utilized in each shift should be included in the calculation.
What Do You Think?
It is not necessary that you need to agree with these views. In case your views are different, please feel free to share them with us. If you are calculating Man-to-Machine Ratio differently, or if you are considering overtime hours when calculating MMR, we’d be interested to hear your approach.
