Choosing a Manufacturing ERP: Questions That Matter

A manufacturing ERP is the system that holds your bills of materials, routings, production orders, stock and product costs in one place, so that planning, the shop floor and the accounts work from the same numbers. Choosing one well is less about comparing feature lists than about answering a short set of questions about how your factory actually makes things, and then making every vendor prove its answers on your own data. Most of those questions are about your business, not about the software.

This post is that question list. It is not a vendor ranking: the vendor documents linked below (checked on 24 October 2026) show what a clear answer looks like, not which product to buy.

Start with how you make things, not with a vendor

Every manufacturing ERP claims to support "manufacturing". The useful question is which kind. A system that excels at repeating the same product from stock can be painful for a business that designs and builds each order once. Write down which mode carries most of your revenue, and which causes most of your headaches. They are often different.

How you make it	What drives production	What the ERP must do well	The question that exposes a weak fit
Make to stock	Forecasts and reorder points	Demand planning, MRP, batch sizes, stock accuracy	Show me how a forecast change ripples into purchase suggestions.
Make to order	A confirmed sales order	Linking each production order to its sales order, promise dates, partial shipments	If the customer moves the date, what happens to the linked orders?
Configure to order	Options chosen at quotation	A configurator that generates a valid BOM and price	Configure this option set and show me the BOM it produces.
Engineer to order	A one-off design	Project costing, engineering changes during the build, milestone billing	How do you track cost against a quote for a product that did not exist last month?
Process or batch	Recipes and formulas	Yields, by-products, grades, unit conversions	Produce this batch at a lower yield and show me what happens to cost and stock.

Running more than one mode is fine, as long as the mix is written down before you choose.

1. The bill of materials: where does the truth live?

The BOM is the spine of a manufacturing ERP. If it is wrong, every downstream calculation (what to buy, what to make, what it cost) is wrong with it, and confidently so.

Questions to answer before selection:

• Who owns the BOM today? Engineering in a CAD or PLM tool, a spreadsheet maintained by one person, or a supervisor's memory? The ERP needs one owner.
• How deep and how unusual are your structures? Multi-level assemblies, sub-assemblies you sometimes buy and sometimes make, by-products, scrap and yield allowances, and components bought by the roll but consumed by the metre.
• How do changes happen? Who approves an engineering change, when does it take effect, and what happens to orders already in progress? Odoo, for instance, puts engineering change orders and version control in its Product Lifecycle Management app, which is installed separately from Manufacturing. Ask every vendor where change control lives and whether you are licensing it.
• Is everything with a BOM really manufactured? Some products are only bundles. Odoo treats these as their own BoM type: its documentation describes kits as "sets of unassembled components sold to customers" and notes that a kit sold only as a product does not need manufacturing operations configured.

The test: hand each vendor your single most complicated real BOM, not a tidy sample, and ask them to load it before the demo.

2. Planning: materials only, or materials and capacity?

MRP works out what to buy and make, and when, from demand, stock and lead times. What it often does not do on its own is decide the exact sequence of jobs on a constrained machine. Microsoft's design notes for Business Central state that the planning system "doesn't include dedicated logic for capacity leveling or fine scheduling" and that this scheduling work is done separately. The same page adds that Business Central "provides a rough-cut schedule to plan reasonable use of resources" and does not automatically create and maintain detailed schedules based on priorities or optimisation rules. For resources marked as capacity constrained, the same section says Business Central "ensures that resources aren't loaded above their capacity", placing each operation in the nearest available time slot: finite loading, though not optimised sequencing.

That is not a criticism. It is the kind of answer you want, because it tells you where the gap is and who fills it. Ask every vendor for the same clarity:

• What is your real constraint? A bottleneck machine, skilled labour, tooling, or material arriving on time. If material is the constraint, MRP done well matters far more than scheduling.
• How often does the schedule change? A plan that holds for a week can be managed by a planner. A plan that changes every hour needs tooling.
• Do setups depend on sequence? If running colours light to dark, or sizes small to large, saves hours of changeover, you are describing finite scheduling, possibly a separate advanced planning and scheduling (APS) tool on top of the ERP, and its own budget line.
• When the plan is overloaded, who notices, and what do they see? This one question separates a planning system from a list of suggestions.

And for every system: MRP output is only as good as the lead times, stock counts and BOMs underneath it.

3. Costing: how will you know what a product costs?

Costing is easy to leave to a default during setup and only notice at the first month-end. Settle it with your accountant before selection, not after:

• Which costing method do you need? Standard cost with variance reporting, moving average, or actual cost per batch or lot.
• How are labour and overhead absorbed? Usually through rates on work centres or operations. Someone has to set those rates and keep them current.
• What happens to scrap, rework and yield loss? Expensed, absorbed into the good units, or reported as a variance?
• Do freight and duty land in product cost? For importers, that separates real margin from imagined margin.

The test: ask to see a completed production order's cost breakdown, and then the journal entries it posted. If the vendor cannot show both in the same session, that is where your month-end will hurt.

4. The shop floor: who records what, and when?

A manufacturing ERP can record far more detail than a factory may be willing to enter. ERPNext's documentation describes a job card as the record that "stores actual production information about a particular Operation performed on a particular Workstation", with operators starting and completing jobs or entering times by hand. Useful, but only if operators record it as the work happens.

Decide, operation by operation, which of these you will do:

• Real-time capture at the station (tablet, terminal or scanner): the best data, and the most discipline required.
• Supervisor entry at the end of a shift: workable, but times become estimates.
• Backflushing, where the system records standard consumption when the order completes: the least effort, and the least visibility into what really happened.

There is also a boundary between the ERP and machine-level systems. ISA describes its ISA-95 standard as defining the interface between business functions and manufacturing control functions. Ask what stays in your MES or machine software and what must reach the ERP: usually quantities, scrap, completions and downtime reasons, not every sensor reading.

5. Quality and traceability: how deep, and who demands it?

Let a customer or regulator set traceability depth, not preference: every extra level adds work at every receipt and production step.

• Lot or serial? Lots for batches of material; serials when each unit must be followed individually.
• Forward and backward: from a raw-material lot to every finished lot and customer it reached, and back again.
• Quality points: at receipt, during production and at final inspection, with a way to quarantine stock that fails.
• Speed of response: some rules set a clock. For foods on the FDA's Food Traceability List, the Food Traceability Rule requires records to be made available to the FDA within 24 hours of a request. The original compliance date was 20 January 2026; Congress has since directed FDA not to enforce the rule before 20 July 2028, and FDA says it intends to comply (page current as of 8 October 2026). If a rule like that applies to you, the ERP has to produce the report, not just store the data.

The test: in the demo, pick one received lot of a component and ask for every finished lot and every customer shipment it went into. Then do it in reverse, starting from a customer complaint. Time both.

6. Subcontracting and outside processing

Many factories send work out: plating, heat treatment, painting, or a whole sub-assembly. Three questions:

• Does the subcontractor buy the material, or do you send yours? Odoo, for example, documents three modes: basic subcontracting, in which "no components are sent" because the subcontractor acquires its own; resupply subcontracting, in which you send the components; and dropship to subcontractor, in which your component vendor delivers straight to the subcontractor. Your process may need more than one.
• Does the system know about stock sitting at the subcontractor? If it does not, planning will order material you already own.
• How is the outside service costed into the product?

7. Integrations: what must the ERP talk to?

List every system that touches production (CAD or PLM, e-commerce or EDI, carriers, MES or time clocks, quality instruments, payroll) and give each an owner, a direction and a frequency. Each integration is a small project of its own, and one discovered after signing is scoped and paid for outside the budget you agreed.

8. Ownership after go-live, and hosting

Somebody has to maintain BOMs and routings, run planning daily, keep work-centre rates current and approve changes. Name those people during selection: a system that needs a full-time administrator is the wrong choice if nobody will be that administrator. Hosting is a separate decision, especially with custom modules or shop-floor integrations; I set out how to make it in cloud ERP vs on-premise in 2026.

Run the demo on your data: a scripted test

A generic demo shows what the software can do; a scripted one shows what it does for you. Send each shortlisted vendor the same package well before the meeting (BOMs, routings, a week of real orders, your costing method) and ask them to run these steps live, in order:

Step	What they do	It passes if
1. Quote to order	Quote a configured or custom product, convert it to a sales order	The BOM and price come from the configuration, not retyping
2. Plan	Run planning on your week of orders	You could explain every suggestion to your buyer
3. Receive	Receive a component with a lot number	The lot is captured at the dock, not later
4. Produce	Produce with some scrap and one failed quality check sent to rework	Stock and cost both change, and you can see why
5. Ship and invoice	Ship part, then the rest, and invoice	Nothing has to be fixed by hand
6. Cost	Show the product cost and the journal entries	Your accountant agrees with the numbers
7. Trace	Trace the component lot forward to the shipment	It takes minutes, not a spreadsheet export

Two or three vendors through this script beat any number of generic demos.

What goes wrong, and how to spot it early

• Choosing on the demo, not the script. Sign: the vendor asks for "a sample product" instead of your BOM.
• Switching MRP on with unclean data. Sign: buyers go back to their own spreadsheets.
• Leaving costing to the defaults. Sign: the first month-end shows variances nobody can explain.
• Over-detailed shop-floor capture. Sign: operations all finish just before the shift ends.
• Customising the planning engine instead of agreeing that a planner, or a scheduling tool, owns sequencing. Sign: a growing customisation list and no agreed scheduling goal.
• Ignoring the minority production mode. Sign: custom orders, subcontracted work or rework still run on paper.
• Adding traceability later. Sign: a customer asks for a trace and the early months have no lot history.

A one-page checklist

Before you sign, answer every line:

• Our main production mode, and the second one we cannot ignore
• Who owns the BOM, and how engineering changes are approved
• Our real constraint: material, a machine, labour or tooling
• Whether we need finite scheduling, and if so whether it sits in the ERP or a separate tool
• Our costing method, how labour and overhead are absorbed, and how scrap is treated
• Per operation: real-time capture, supervisor entry or backflush
• The traceability depth a customer or regulator requires, and how fast we must answer
• How subcontracted work and stock held at subcontractors are handled
• Every integration, with an owner, direction and frequency
• Who maintains the system day to day after go-live
• The scripted demo results for each shortlisted vendor

Where I can help

If you already run Odoo and want to know whether your custom modules and integrations will hold up as production grows, or what an upgrade would break, my technical architecture review covers custom modules, integration patterns, infrastructure and upgrade compatibility, and ends with a written report and a walkthrough call. If you are at the implementation stage and looking at Odoo or ERPNext for production, get in touch with this checklist half filled in.

Frequently Asked Questions

What is a manufacturing ERP?

An ERP with production built in: bills of materials, routings, work orders, material planning, shop-floor recording, lot tracking and product costing, sharing one set of data with sales, purchasing, inventory and accounting.

What is the difference between MRP and ERP?

MRP (material requirements planning) is the calculation that turns demand, stock and BOMs into suggestions for what to buy and make, and when. ERP is the wider system that contains MRP alongside sales, purchasing, inventory, accounting and often HR. In current systems MRP is normally a function inside the ERP rather than a separate product.

Do we need finite capacity scheduling?

Only if a constrained resource, such as a bottleneck machine or a scarce skill, decides your delivery dates and the schedule changes too often for a planner to manage by hand. Some ERPs plan materials and cap the load on constrained resources but leave detailed sequencing to a planner or a separate tool; Microsoft documents that split for Business Central. Ask each vendor directly how overloads are detected and resolved.

Should a small manufacturer choose an industry-specific ERP or a general one?

Choose the one that passes the scripted demo on your hardest products. An industry-specific system may fit a regulated or unusual process with less configuration; a general ERP may cover more of the business around production. For either, ask who near you can implement and support it.