Matt Barber
"What's the difference between process and discrete manufacturing?"
It's one of the most common questions in manufacturing, and the answer has a big effect on which systems fit.
The simple version
Discrete: the final product could, in theory, be taken apart back into its components. A bike.
Process: no matter what you do, you can't get back to the raw materials. A cake. You're never getting that egg back.
That's the core idea. In practice each side splits into a few types, and plenty of factories run more than one.
Discrete manufacturing
Individual, countable items. You count pieces, and often track serial numbers. Within discrete, there are distinct patterns.
Repetitive. The same or similar products run continuously on dedicated lines at high volume. Think automotive components, consumer electronics, white goods or packaged goods. Performance is about line rate and OEE.
Job shop or high-mix, low-volume. Many different products in small quantities, each following its own route through shared machines. Think machining or fabrication. Changeovers and scheduling are the big challenges.
Assembly. Components brought together into a finished product, from simple kits to complex machines. Getting parts to the line when they're needed, in sequence, matters most, along with recording which components went into which unit.
Process manufacturing
Materials are transformed: mixed, blended, heated or reacted. You measure in kilograms and litres, not pieces. Recipes and formulations matter, and natural variation in raw materials means yield varies too.
Batch. A defined quantity is made in one run, following a recipe, and the whole batch is treated as one unit for quality and traceability. Common in food, pharmaceuticals, cosmetics and speciality chemicals.
Continuous. Material flows through the process without stopping, often 24 hours a day, for weeks or months. Think refining, paper, steel, extrusion or bulk chemicals. Stopping is expensive, so stability and process control are everything, and traceability is often time-based rather than by lot.
Mixed-mode
Many manufacturers don't fit one category. A food company mixes a batch (process), then fills and packs it into cases (discrete). A plastics company runs a continuous extrusion line that feeds discrete cutting and packing.
Mixed-mode is common, and the handover points between modes are where systems are most tested.
Side by side
| Type | Unit of measure | Traceability | What drives performance | Examples |
|---|---|---|---|---|
| Repetitive | Pieces | Lot or serial | Line rate and OEE | Automotive parts, electronics |
| Job shop | Pieces | Lot or serial, by order | Changeovers and scheduling | Machining, fabrication |
| Assembly | Pieces | Serial, with component genealogy | Material availability and sequence | Machinery, vehicles |
| Batch | Weight or volume | Batch or lot | Recipe adherence and yield | Food, pharma, cosmetics, chemicals |
| Continuous | Weight or length | Time-based | Stability and uptime | Refining, paper, steel, extrusion |
| Mixed-mode | Converts between them | A mix | All of the above, at the handover points | Food, pharma, plastics, packaging |
A separate question: how you respond to demand
People often mix manufacturing type up with production strategy, which is a different axis:
- Make to stock: build ahead of demand to forecast.
- Make to order: build once the customer orders.
- Configure to order: build a standard product with customer-chosen options. More in From CPQ to the shopfloor.
- Engineer to order: design and build something unique for each customer.
A job shop can be engineer to order, and a repetitive line can be make to stock. Both axes shape what you need from MES/MOM.
Why the type matters for MES/MOM
The type of manufacturing shapes almost every decision in a project.
Process design. Repetitive lines think in rates. Job shops think in routings. Batch thinks in recipe steps and parameters. Continuous thinks in stability over time.
Data and KPIs. Units of measure, how you calculate yield, how traceability works (serial, lot or time-based), and which quality checks matter.
Operator screens. A discrete operator wants to see the next part and its count. A process operator wants the current recipe step and its parameters. Same system, very different screens.
Technology choice. Not every MES handles every type well. Some were built for discrete and stretched into process, or the other way round. You'll feel that in unit-of-measure handling, recipe management, traceability and mixed-mode handovers.
What to ask a vendor
Pin this down early in any evaluation:
- Can you show me my type of manufacturing running in your system, not a similar one?
- How do you handle mixed-mode, where one line is process and the next is discrete?
- How do units of measure convert between operations, from kilograms in to cases out?
- How do you handle time-based traceability on continuous lines?
- Is all of that done through configuration, or customisation?
My view
I've been explaining MES for well over a decade, and this question matters more than people realise. Mixed-mode is far more common than most software brochures suggest. I'd look for a platform that handles every mode across the enterprise through configuration. If a vendor needs custom work to handle your basic manufacturing type, that's a warning sign. More on that in Configure, don't customise.
How would you describe your own manufacturing: one type, or a mix?
