Manufacturing Software: ERP or Custom-Built?

A 35-employee manufacturer receives an ERP quote: annual licence per user, five-figure implementation, fourteen months before go-live. In the meantime, production keeps running on three Excel files and a whiteboard. The question isn't whether the ERP is any good — it usually is. The question is: are your processes standard enough to fit inside an ERP, or is the way you work exactly what sets you apart? If four of your five main processes are standard, buy an ERP. If the one that wins you contracts is unusual, a custom tool built around that process will cost less and be in service far sooner.

This guide isn't an argument against ERPs. It's a way to decide with your eyes open, before you sign.

Discrete manufacturing or continuous process: why it changes everything

Before comparing software, you need to know which family you're in. It's the first filter, and it eliminates half the candidates.

Discrete manufacturing produces things you can count: doors, conveyors, cabinets, machined parts. It organizes around multi-level bills of materials, routings, work orders and sometimes serial numbers. The central question is "where is job 4712, and what's blocking it".

Continuous process manufacturing produces volumes: paint, food, chemicals. It organizes around recipes, batches, yields and regulatory traceability. The central question is "which batch, which formula, which yield".

Software built for one is uncomfortable in the other. Plenty of small manufacturers get shown a continuous-process tool because it's popular with the food plant next door, then spend six months bending it around discrete production. That's the first money lost — before the first line of configuration.

The three possible paths

Once you know your family, there are three routes — not two. The third is the one most often forgotten.

The general-purpose ERP. A suite covering accounting, purchasing, inventory, production, sometimes payroll. You buy complete coverage and a proven method. In exchange, you adapt the way you work to the software, and you configure for a long time.

The vertical solution. Software built for one industry — machining, cabinet making, structural welding. Less configuration, vocabulary your people recognize, but a smaller vendor and a narrower scope.

Custom, delivered tile by tile. You don't build "your ERP". You replace the Excel file that hurts most — production tracking, usually — with a tool that does exactly that, in a few weeks. Then you look at what hurts next. Accounting stays in your current accounting software, which handles it perfectly well.

The comparison table

What an ERP does better — and when it's the right call

It needs saying plainly: in several situations the ERP is the right answer, and custom would be an expensive mistake.

An ERP is right when accounting, purchasing, inventory and production genuinely need to live in one system — because you have multiple sites, multiple currencies, or audit requirements that make bridges between tools hard to defend. It's right when your processes look like your competitors': you then have no reason to pay to reinvent what the industry already standardized.

It's also right when you want long-term independence. A widely used ERP means a pool of integrators, consultants and employees who already know it. If your vendor disappoints you, you change vendors without changing software — a real advantage no custom solution offers.

Finally, past roughly a hundred employees with several departments passing information back and forth all day, the question mostly answers itself. At that size, the cost of coordination exceeds the cost of the licence.

What custom does better in a 10 to 80 employee shop

Below that size, the equation often flips, for three reasons.

Your exceptions are your advantage. Small manufacturers that survive rarely do it by being the cheapest. They do it by taking the orders others turn down: the special part, the tight deadline, the mid-run change. Those exceptions are exactly what a standard ERP handles poorly — and forcing them into the software costs more than the software itself.

Timeline matters as much as function. A production tracking tool delivered in three weeks and used every day beats a complete ERP going live in fourteen months. In between, you spent another year on spreadsheets.

Adoption on the floor decides everything. An operator wearing gloves who has to navigate six screens to change a status won't do it. He will if it's one button on a tablet. A tool built for your floor wins that fight, and it's the only one that counts: software nobody fills in is worth nothing, whatever it cost.

Our guide on production tracking shows what that first tile looks like in practice, and our page on custom software for manufacturers shows where we usually start.

The real five-year cost

Comparing a licence price to a development price makes no sense. You have to compare complete costs over the same period. Here's the mechanism — the amounts depend entirely on your situation.

On the ERP side, add up: the licence per user times the number of seats times sixty months; the initial implementation, which frequently reaches one to two times the annual licence cost; customization of whatever doesn't fit the standard; annual maintenance, often expressed as a percentage of the licence; data migration; training; and the internal project cost — the weeks your best people spend configuring instead of producing. That last item never appears in a quote, and it's often the largest.

On the custom side, add up: development of each tile; hosting, generally modest for an internal application; and enhancements, which are an annual choice rather than a mandatory subscription. The risk here isn't cost — it's dependence on a single vendor. So insist that the code belongs to you and that it's documented: that's what lets you change vendors.

For hard numbers on the Québec market, see our guide on the cost of custom software.

How to decide in a week

You don't need a consulting engagement to answer this. You need a sheet of paper and an hour with your two or three key people.

Write down your five main processes — quoting, purchasing, scheduling, production, shipping, for example. Next to each, write standard or unusual, honestly: "standard" means a competitor would do it roughly the way you do.

If four or five are standard, go with the ERP or the vertical solution — and don't try to customize it. The standard is what you're buying.

If one or two are unusual and they're the ones winning you contracts, don't force them into a suite. Build those custom and leave the rest in standard tools.

If you can't decide whether a process is standard or unusual, that's almost always a sign the process isn't yet clear inside the company — and no software, at any price, will settle that for you. Our guide on custom software vs off-the-shelf applies the same reasoning to other kinds of businesses.