MES software, short for Manufacturing Execution System, records and makes use of what actually happens in production. This function models your site in units, workshops, lines, steps and equipment, captures shop floor data automatically, then calculates indicators from configurable formulas. OEE, throughput rates, yields and trends are all read in one place, with the same definition from one workshop to the next.
The ISA-95 standard places this layer between the process and the business: it turns what happens on the shop floor into information the organisation can use.
Why no two workshops ever calculate the same indicator
Ask for the OEE of two different lines and you will get two figures built in two different ways. One excludes planned stoppages, the other counts them at half weight. One works from opening time, the other from required time. Each has its reasons, and each will defend its method in the meeting.
The problem is not the figure, it is that it compares to nothing. Not to the workshop next door, not to the same workshop six months earlier, not to another site in the group. Every investment or prioritisation decision then rests on data that does not add up.
A single data model settles this before it becomes a question. The site is modelled once, the formulas are defined once, and the same indicator means the same thing everywhere.
How it works
The site is described in units, workshops, lines, steps and equipment. Everything else builds on that.
Data sources are declared: PLCs, SCADA, existing databases, manual entry.
Extractions run on a scheduler, which makes data capture regular and auditable.
Indicators are produced from configurable formulas, with their own units and constants.
Values are followed over time and compared against the budget set for the period.
A month’s data can be corrected with a full audit trail, without rewriting history.
Three situations this feature addresses
Production is run on manual readings
The situation: Today’s figures arrive tomorrow, typed up at the end of a shift into a spreadsheet that goes round by email. Nobody really disputes them, but nobody would defend them in front of an auditor either.
What the software does:
- Automatic capture from PLCs and SCADA
- Scheduled extractions that do not depend on anyone being available
- A full audit trail of any correction made afterwards
What changes: The figure becomes defensible, and the time spent producing it disappears.
Every workshop has its own definition of OEE
The situation: Calculation methods differ from one line to the next, often for good historical reasons. Comparisons become impossible, and performance meetings turn into arguments about method.
What the software does:
- A single site data model, shared by every function
- Formulas defined once and applied everywhere
- Units and unit families handled consistently
What changes: The meeting is about the results, not about how they were worked out.
You only see the drift in the monthly report
The situation: A yield sliding slowly does not show up day to day. It appears in the monthly figures, when the month is already gone and all that is left is to explain it.
What the software does:
- Trend monitoring over time, by equipment or by line
- Continuous comparison of actual against budget
- Indicators available without waiting for month end
What changes: The drift gets dealt with while it can still be corrected.
What this function covers
MES, ERP, SCADA: who does what
| System | Role | Time frame | The question it answers |
|---|---|---|---|
| ERP | Orders, stock, purchasing, invoicing | Day to month | What have we sold, and what do we need to produce? |
| MES | Production achieved, OEE, downtime, quality | Minute to day | What actually happened in production? |
| SCADA | Equipment control and status | Second | What is the machine doing right now? |
The three do not replace each other, they stack. An ERP without an MES plans on figures typed in by hand. A SCADA without an MES controls the plant properly but keeps nothing usable once the day is over. The MES is the layer that makes the other two add up.
How to choose MES software
Four criteria matter more than the length of the feature list.
- Connecting to what you already have. The ability to hook into PLCs and existing equipment drives the real cost of the project, far more than the licence price.
- How much your teams can do themselves. Software where every new report means a change request stays expensive for ten years. Being able to build your own outputs changes the economics.
- A consistent data model. Without a shared model across workshops and sites, indicators cannot be compared, and the MES only ever produces isolated figures.
- The ability to work on site. An MES project means cabling, connecting and commissioning. A vendor who subcontracts that adds a party to the project and a grey area of responsibility.
Where this function delivers the most
Factories, process plants and production sites of every size: what matters is the structure of the plant and the way it is measured, not the industry.
Case studies
One software package, several functions
Our PILOT software also covers truck flows, site access, weighing, the laboratory, downtime, reporting and integration with your business systems, all on a shared site data model.
You only turn on what you need, and you extend when the need arises, without changing tools or rebuilding interfaces.
The other functions
Production tracking shares its data model with the other functions. Each one runs independently, on the same foundation.
