Definition
A manufacturing execution system sits between the administration and the machines. It hands works orders to the floor, records start and stop times, downtime, scrap and quantities, and reports back how much was really made and how long it took.
What it means for the calculation
An MES supplies the times that let a calculation be checked afterwards. Without that recording, a shop is left with estimated times nobody has ever held against reality. With it, it becomes visible which operations structurally take longer than planned, and that is the most direct way to make a time standard better. Entering and maintaining the data also takes time on the floor, and that time belongs in the trade-off.
Where this comes up
On the terminals beside the machines, in the hour registration per works order, and as the source for downtime and scrap figures.
Common mistakes
Reading recorded hours without the context: a long booking can be a long operation or a forgotten stop. Also thinking that recording by itself improves the times; that only happens once someone feeds the deviation back into the time standard.
An MES supplies the times that let a calculation be checked afterwards. Without that recording, a shop is left with estimated times nobody has ever held against reality. With it, it becomes visible which operations structurally take longer than planned, and that is the most direct way to make a time standard better. Entering and maintaining the data also takes time on the floor, and that time belongs in the trade-off.
See how Blake reviews a partFrequently asked questions
What is the difference with ERP?
ERP manages the order and the administration; MES drives and records execution on the floor.
Does a small shop need an MES?
Not necessarily; hour registration per works order in the existing system gives part of the same information.
Does an MES automatically produce better estimates?
No, it produces data; someone has to set it beside the planned times and adjust the standard.