ERP vs MRP: Where a Small Manufacturer Can Stop, and Where It Cannot

MRP software plans what to buy and what to build: it reads your bills of material, your stock and your production schedule and tells you which materials you need and when. ERP does the same planning, but inside one system that also runs finance, purchasing, sales and inventory. A small manufacturer with one site, one legal entity and simple assembly can usually stop at MRP plus an accounting package. Once you add a second entity, a second site, variant configuration, batch production or audited traceability, an MRP-only setup starts costing more in workarounds than an ERP costs in licences.

This guide is for owners and operations leads at manufacturers with roughly 10 to 100 employees who are deciding between the two. It uses the published prices and documentation of standalone MRP vendors, read on 27 October 2026, the pricing data behind the ERP Pilot comparison, and a replay of our scoring engine for a typical small manufacturer. The systems that come up most often for that profile are Odoo, Microsoft Dynamics 365 Business Central, Acumatica, SYSPRO and SAP Business One.

What is the difference between MRP and ERP?

MRP, material requirements planning, is a calculation: take the demand from the production schedule, explode it through the bills of material, subtract what is in stock or already on order, and the result is a time-phased list of purchase and production orders. The method was set down by Joseph Orlicky in Material Requirements Planning, first published by McGraw-Hill in 1975, and it has not changed in principle since.

ERP, enterprise resource planning, grew out of that calculation. It keeps MRP as one module and puts the general ledger, accounts payable and receivable, purchasing, sales orders, inventory valuation and, depending on the product, warehouse, quality, service and payroll into the same database. Every modern manufacturing ERP contains an MRP run. The reverse is not true.

In practice the line is blurrier than the table suggests, because standalone MRP vendors have added sales, purchasing and some accounting, and entry-level ERPs have become cheaper. That is why the useful question is not the definition, but where your own requirements sit.

What does a standalone MRP system actually cover?

More than the name says, and less than an ERP. Take MRPeasy, one of the few standalone MRP products with a full public price list. Its Starter plan costs $49, Professional $69 and Enterprise $99 per user per month on monthly billing. Users one to ten are charged at the plan rate; from the eleventh user, each block of ten users costs $79 a month. Multiple stock locations and multiple production sites are only part of Enterprise and above.

Every plan lists a "standard accounting" module. MRPeasy's own description is careful about its scope: it covers the most common accounting tasks for manufacturers, while country-specific tasks such as comprehensive reporting to authorities, local payroll compliance and bank communications are not included and, in MRPeasy's words, typically require local software. For Xero users, MRPeasy recommends running operations in MRPeasy and accounting in Xero, synced either at document level or with full journal entries for inventory and production.

That is the typical MRP architecture: planning and the shop floor in one tool, the books in another, joined by an integration. Other vendors package it differently. Katana, for example, now lists a free plan for up to 30 SKUs and sells its full product only as a custom annual contract without a public price, so it cannot be compared on list price.

Where does an MRP-only setup break?

At the points where planning stops being the whole problem. Five requirements push small manufacturers from MRP to ERP more than any others:

• A second legal entity. A sales company abroad or a separate holding means intercompany orders, transfer prices and consolidation. Standalone MRP tools are built around one company; the consolidation then happens in a spreadsheet next to the accounting package.
• A second site or real warehouse structure. Several plants, bin locations or a third-party warehouse need stock that is valued and moved across locations. On MRPeasy that already means the Enterprise plan; beyond that, warehouse depth is where ERPs separate themselves.
• Variant configuration. When customers order a product in hundreds of combinations, the bill of material has to be generated from rules, not kept as a list. Many entry-level systems stop here, ERPs included.
• Process or batch production. Recipes, potency, co-products and lot genealogy for recalls are a different planning model from assembly.
• A finance team that needs one truth. When margin per order, work-in-progress valuation and the month-end close depend on exports between two systems, the integration has become the system of record.

One of these is a reason to start looking. Two or more, and the cost of the workarounds usually exceeds the cost of an ERP within two to three years. Our manufacturing ERP overview goes deeper into the requirements per manufacturing type.

How do your requirements change the ERP shortlist?

Mainly at the manufacturing question, much less at company size. We replayed the ERP Pilot scoring engine on 27 October 2026 with a baseline company of 21 to 100 employees in discrete manufacturing, one country, one legal entity, US GAAP, cloud, light MRP with simple assembly, a basic warehouse and a budget of $100 per user, then changed one answer at a time across all 20 systems in the English comparison.

Source: replay of the ERP Pilot scoring engine, 27 October 2026, English system set of 20 systems. One answer changed per row; all other answers as in the baseline. The baseline knockouts are SAP Business ByDesign (no longer sold to new customers), Sage Intacct and Unit4 (no manufacturing module).

Shrinking the company to under 20 people changes nothing at the top. Adding a second legal entity reorders the leaders but keeps the same four. The manufacturing answer is different: variant configuration and process manufacturing each knock out two more systems, Odoo and SAP Business One, and bring specialists such as proALPHA and Sage X3 into the top four.

Score of the top-ranked ERP as manufacturing gets more demanding

	Top score
Light MRP, simple assembly (baseline)	155
Standard discrete manufacturing	130
Advanced warehouse	115
Process or batch manufacturing	110
Complex discrete, variant configuration	105

Source: replay of the ERP Pilot scoring engine, 27 October 2026, English set of 20 systems, baseline small discrete manufacturer as described in the text, one answer changed per bar. Scores have no unit; a lower top score means fewer systems fit the requirement well.

The chart shows the second effect. The best match for a light-MRP shop scores 155; with variant configuration, the best remaining system scores 105, 32% lower. The field does not just get smaller, it fits less well. That is the practical meaning of "outgrowing MRP": the requirements that push you towards ERP are also the ones where the choice of ERP matters most.

What does each option cost for 15 users?

On subscription alone, the gap between standalone MRP and an entry-level ERP is smaller than most buyers expect. For 15 users, MRPeasy Professional costs $9,228 a year at list price and Enterprise $12,828. Odoo Enterprise ranges from $4,500 to $8,100 a year in our pricing data, below MRPeasy at the low end, and Business Central from $14,400 to $19,800.

Yearly subscription at list price for 15 users

	Per year
MRPeasy Professional (standalone MRP)	$9,228
MRPeasy Enterprise (several sites)	$12,828
Odoo Enterprise: $4,500 to $8,100	from $4,500
Dynamics 365 Business Central: $14,400 to $19,800	from $14,400
SYSPRO: $13,500 to $27,000	from $13,500
SAP Business One: $19,800 to $39,420	from $19,800
Acumatica (resource based): $21,600 to $32,400	from $21,600

Sources: MRPeasy from the MRPeasy pricing page (27 October 2026), monthly billing, ten users at plan rate plus one ten-user bundle. ERP ranges from the ERP Pilot pricing data (list price, 15 users, 12 months). Acumatica is priced by resources, not users. Bars and end values show the low end of each range.

Two things need context. Odoo's low end is its Standard plan with one company and Odoo-hosted cloud; a second entity or custom modules move it to the upper end. And Acumatica sells resource tiers with unlimited users, so it looks expensive at 15 users and becomes relatively cheaper as headcount grows. Detailed figures per system are on the pricing pages for Odoo, Business Central, SYSPRO, SAP Business One and Acumatica.

The MRP figure also leaves out the accounting package it depends on. A QuickBooks or Xero subscription sits on top, plus the integration. When the shop is outgrowing that accounting package too, our guide on outgrowing QuickBooks sets out the thresholds.

Why is implementation the bigger cost line?

Because an ERP replaces several processes at once, and that takes a project. Over three years, at 15 users and the low end of our ranges, implementation makes up 51% of Odoo's total, 37% of Business Central's and 43% of SYSPRO's. Standalone MRP tools are built to be set up largely by the customer, which is the real saving, more than the subscription.

Three-year cost for 15 users, subscription plus implementation

	Over three years
MRPeasy Professional (subscription only)	$27,684
Odoo Enterprise: $29,175 to $105,515	$29,175
Dynamics 365 Business Central: $68,200 to $209,400	$68,200
SYSPRO: $70,500 to $281,000	$70,500
SAP Business One: $100,092 to $259,547	$100,092
Acumatica: $114,800 to $297,200	$114,800

Source: ERP Pilot pricing data and TCO model (36 months of subscription at list price, implementation range scaled to 15 users, maintenance where it applies). Bars and end values show the low end of each range. MRPeasy: 36 months of Professional for 15 users from the MRPeasy pricing page, 27 October 2026, without onboarding services or the accounting package.

This is the honest case for staying on MRP: a shop that can run on $27,684 of subscription over three years should not take on $15,000 or more of implementation without a reason. The reason has to be work the ERP removes, such as the duplicate entry between two systems, the spreadsheet consolidation or the manual lot trace before an audit. Our guide to ERP implementation costs breaks those project lines down.

Can you start with MRP and move to ERP later?

Yes, and for many small manufacturers that is the right sequence, provided you plan the exit from the start. MRP data, meaning items, bills of material, routings, work centres and stock, is exactly what an ERP needs on day one. Clean data in a well-run MRP makes the later ERP project shorter, not longer.

Three choices made now keep that path open:

1. Keep item numbers and bills of material clean and exportable. Avoid free-text components and one-off items that only exist in a spreadsheet.
2. Post full journal entries to the ledger, not only invoices. If inventory and production costs already reach the accounting package as journals, the opening balances for the ERP are a mapping exercise, not a reconstruction.
3. Write down the trigger. Decide in advance which event starts the ERP selection: the second entity, the second site, the first customer audit demanding lot genealogy. Then start the selection 9 to 12 months before that event, not after it.

The move itself follows the usual pattern: cut over at a fiscal year or quarter end, migrate master data and open items, keep the old system read-only. The ERP implementation timeline guide covers how long each phase takes for a company of this size.

Which path fits your shop?

Use the table as a first filter. If all your answers sit in the left column, an MRP tool plus your accounting package is enough for now. Any answer in the right column is a reason to put ERP on the shortlist.

If ERP is on the list, the shortlist depends on the manufacturing type far more than on size, as the replay showed. For light and standard discrete manufacturing, Odoo, Business Central, Acumatica and SYSPRO are the usual starting set. For variant configuration, look at Acumatica, proALPHA and Epicor Kinetic. For process and batch production, SYSPRO and Sage X3. The ERP guide for manufacturers compares those systems by manufacturing type in more depth.