MES and Batch

Order execution, traceability, genealogy and electronic records. Usually the most over-scoped project in a plant, and the one most often justified after the fact.

What MES and batch actually are

A manufacturing execution system sits at ISA-95 Level 3, between the business systems that plan production and the control systems that run it. ERP decides what to make this week. SCADA and the PLCs decide how fast a motor turns right now. MES manages everything in between: which order runs on which line, what materials went into it, who did what, and whether the result met specification.

The core MES functions are consistent across vendors:

• Production tracking: dispatching work orders to lines, recording starts, stops, counts and scrap against each order.
• Genealogy and traceability: which lots of raw material went into which lots of finished product, so a recall can be scoped in minutes rather than days.
• Quality: in process checks, specification limits, sampling plans, holds and release.
• Performance and OEE: availability, performance and quality losses tied to the order, product and shift that caused them.
• Electronic records: work instructions, sign offs and an audit trail, which in regulated industries must meet requirements such as FDA 21 CFR Part 11.

Batch control is a related but distinct discipline, defined by ISA-88. It applies where product is made in discrete quantities through a sequence of steps, as in food, beverage, chemicals and pharmaceuticals. ISA-88 separates the recipe (what to make) from the equipment (what makes it). Recipes are built from procedures, operations and phases. Equipment is modelled as process cells, units and equipment modules. A phase such as “add ingredient” or “heat to temperature” is written once in the controller and reused by every recipe that needs it. That separation lets a plant add a product without rewriting control code.

For a longer introduction, see our overview of manufacturing execution systems and our piece on MES, quality and traceability.

How MES differs from SCADA and ERP

SCADA shows and controls the process in real time and alarms when something goes wrong. It thinks in tags and seconds. ERP manages orders, inventory, cost and purchasing. It thinks in transactions and days. MES thinks in orders, lots and shifts. It knows that this run of this product used these materials and produced this many good units. A modern SCADA platform can take on some MES functions, and ERP vendors sell shop floor modules, which is exactly why the scope needs to be drawn deliberately.

The problems we see most

Projects that stall. The most common pattern is a plant wide rollout that tries to deliver every module at once. Requirements grow to match the vendor brochure, integration drags, and the plant ends up running old spreadsheets beside a half built system.

Paying twice. Functions the historian, SCADA or ERP already handle get bought again in the MES, and the two copies disagree.

Weak foundations. An MES is only as good as the signals it receives. If line states are inconsistent and counts are unreliable, OEE and genealogy will be wrong from day one.

Batch code that is not really ISA-88. Recipes hard coded into the PLC and phases that differ line to line, so adding a product means a controls change.

The decisions this layer forces

Build, buy or extend. A packaged MES suits plants with complex genealogy, regulated records or many sites to standardise. Extending your SCADA platform with MES modules often suits a single site that mainly needs tracking and OEE. Custom builds rarely survive the person who wrote them. We will tell you which we think fits, and why.

Start narrow. We recommend one line, two or three functions, and acceptance criteria agreed before the build. Prove it, then expand.

Place each requirement at its level. Every requirement gets assigned to ERP, MES, SCADA or the controller before anyone looks at products. Most scope problems disappear at that step.

How it connects to adjacent layers

MES consumes events from SCADA and historians and from the controls layer, where ISA-88 phases live. It depends on clean, contextualised plant data and on an OT network that can carry traffic between plant and business systems safely. Counts and states increasingly come from the edge.

Where Joltek helps

We run independent MES selection, from requirements to scored demos on your own data, and stay on as your owner’s engineer through implementation. If the immediate goal is a downtime picture people trust, start with OEE and downtime improvement. For connecting MES to ERP and the floor, see IT/OT integration. Batch and traceability are central to food and beverage plants, where much of this work happens.