«Where are we with this order?» It is a simple question. In many companies answering it means calling the shop floor, waiting for someone to gather the numbers and checking they are up to date. Half a day goes by, and meanwhile the delay has grown.
The scene I see most often is always the same. The office prints sheet after sheet, the sheets reach the floor, some get lost along the way, and there is always one person chasing everyone to understand what is going on. Going digital helps, there is no denying it.
A MES is there to answer that question in a second.
01What it is, in one sentence
A MES (Manufacturing Execution System) is the system that tells you what is happening in production and compares it with what should be happening.
Where the MES sits
Between the business system and the machines, as in the industry's reference standard, ISA-95
- knows which orders must be produced
- customers, materials, costs
- knows how it is really going
- progress, parts, scrap, delays
- know what they are doing
- PLCs, sensors, operators
The ERP, the business management system, knows which orders must be produced. The machines know what they are doing. The MES connects the two: where an order stands, how many parts were produced, how many scrapped, where delays are building up. You move from knowing what you have to produce to knowing how it is really going.
02What it does
Brings orders to the floor
In the right order and to the right line.
Collects data
From machines and operators: quantities, times, stops, scrap.
Tracks progress
Of every order, as it happens, not at the end of the shift.
Traces what went where
Which material lot is in which part.
Records quality
Checks, results, non-conformities.
Measures performance
Why a line is stopped, how much it delivers compared with what it could.
You don't need all of them from day one.
03ERP, MES, dashboard: the difference in three lines
The most common confusion is thinking that having the data in the ERP, or seeing it in a dashboard, means having production under control. The distinction I use:
Manages
orders and the business process.
Runs
the execution of production.
Shows
the information that exists.
A dashboard shows data. It does not manage order progress, traceability, scrap or the rules needed to coordinate the shop floor.
04The signs you need one
- To know how production is going you have to ask someone and wait for them to rebuild the data by hand.
- Orders live in one place, machine data in another, and progress lives on paper or in Excel.
- You cannot quickly answer simple questions: where an order stands, how many good parts, how much scrap and why, why that line is stopped.
of small and mid-sized manufacturers still use paper or spreadsheets instead of a MES
IoT Analytics, 2025It does not mean you need a complete MES right away. It means there is a visibility and coordination problem worth looking at.
05«MES is for big companies»
No. You need to understand which problem you want to solve and choose a proportionate solution. Buying a huge system when a well-bounded problem would be enough to start from is the fastest way to spend a lot and use little.
06Where to start
From a concrete problem, not from buying a complete MES.
- Step 1Pick one line or one family of machines.
- Step 2Work out which information is missing: order progress, quantities, scrap, times and reasons for stops.
- Step 3Build a first solution that collects it reliably and brings it to whoever makes decisions.
- Step 4Only when it really works, extend it to the other lines and add functions.
Foundations that let you grow, without doing everything at once.
07What a MES doesn't do
People who buy a MES sometimes expect it to solve on its own problems that are organisational, or that depend on data quality. Then they discover that the machines don't expose all the information, that operators record things in different ways, that nobody has decided how scrap and stops are logged.
The value of a MES is not the report done sooner. It is being able to decide while the problem is still manageable.
For where the market is heading and how I think about architecture, read the future of MES in 2027.
