You go out to tender to overhaul your information system, and the same sentence comes back in every proposal: "our ERP includes a maintenance module". The comparison grid in your RFP then raises the ritual question: ERP with a CMMS module, or dedicated CMMS? The debate starts, the columns fill up, and nobody notices that the question is the wrong one.
It assumes that a CMMS is a small niche tool to be bolted onto the side of a large general-purpose system. For a plant maintaining its own production lines, that is a fair assumption. For a company that sells maintenance — HVAC, refrigeration, electrical, multi-technical, lifts, fire safety — it is exactly the opposite. Your value chain, from quote to invoice, is the native scope of a vertical CMMS. Here is why that changes the conclusion.
An ERP's maintenance module was not designed for your business
This is not about the quality of the vendor. It is about original purpose, and it has very concrete consequences.
An ERP maintenance module almost always originated in an industrial context: a plant, an asset base, internal work orders, cost allocation against cost centres. None of that assumes you invoice a customer at the end. Yet your business starts with a quote and ends with cash collected. In between there is a contract, response-time commitments, contractual preventive visits, out-of-contract work to get signed off, and hours to be valued at the right rate. That commercial thread is not in the module's DNA — it gets added on.
The gaps are always the same ones:
- Mobile. Either it barely exists, or it is a stripped-down version of the web app. The test is simple: a basement plant room, a rooftop, a boiler house. Without full offline mode — asset history, report entry, photos, customer signature — the technician walks out with a paper form and someone re-keys it that evening.
- Multi-level maintenance schedules. A quarterly schedule, a half-yearly one and an annual one on the same asset family, with nested tasks: that is daily life on a full-cover maintenance contract. Few generic modules handle it without contortions.
- Contracts with recurring billing. Automatically invoicing contract fees, at the right frequency, with price indexation, and separating what is included from what is chargeable as an extra.
- Scheduling. Assigning the right skill and the right certification to the right place, and optimising routes. A generic calendar is not a field service management tool.
- The customer portal. Raising a service request, tracking its progress, downloading reports and safety logbooks. Your clients increasingly ask for this in their specifications.
Every one of these gaps gets filled with custom development. That is where budgets slip and timelines stretch: not on the ERP core, which does its job very well, but on the months of configuration and development needed to recreate what a maintenance management system does out of the box. And custom work is paid for twice — once when it is built, then again at every upgrade. The module ticks the box in the comparison grid. It does not deliver in the field.
A vertical CMMS covers the whole chain, from quote to invoice
Walk through your business link by link and see where it sits.
A request comes in — via the customer portal, by email, by phone, as a ticket. It becomes a qualified service request, linked to a site, a customer and an identified asset. If it falls outside the contract, it generates a quote, which is sent, chased and signed electronically. The signed quote generates the job. If it is contractual, the contract's preventive maintenance plan generates the year's work orders on its own, with the associated task lists.
Those jobs are then scheduled: skills, certifications, geographical areas, response-time commitments, route optimisation. They are carried out on mobile, including with no network coverage: readings, checkpoints, before/after photos, parts used, time spent, customer signature on site, report sent immediately. They are invoiced — on actuals, on a fixed price, or against a contract billing schedule — then tracked through to payment and chasing. And at every stage, margin is calculated: by contract, by customer, by site, by technician.
That scope is the scope of an industry-specific ERP. Not of a bolt-on tool. It is what Yuman has been doing as standard for ten years, across an installed base of 1.6 million assets, more than 15,000 active users and around €400M of revenue invoiced every year through the platform, in over 15 countries. Groups such as Descours & Cabaud (Prolians), Engie, SKF, Groupe NGE and Emeria use it across their service operations.
Specialisation shows up most clearly in the areas where a general-purpose module falls short. French e-invoicing for 2026-2027 and Peppol are supported natively, including for job invoices originating in the field — rarely the case for a maintenance module attached to an ERP where only central invoicing has been brought into compliance. Security follows the same standard: ISO 27001 certification, GDPR compliance, European hosting. And built-in AI works on precise business cases: rewriting and checking job reports, diagnostic assistance, detecting work carried out but never invoiced. That last point alone adds up quickly in a company with 40 technicians.
If you want the link-by-link detail, the full inventory is here: what features does a CMMS include. And to see where a CMMS sits relative to technical supervision tools, see BMS and CMMS: what's the difference.
"But I still need an ERP, don't I?"
Sometimes you do. You just need to be clear about what for.
What a CMMS does not do, and is not meant to do: general accounting, payroll, group consolidation, managing a trading inventory of several thousand SKUs. Everything else in your operations, it carries.
Two set-ups work well.
- Maintenance SME, 10 to 150 technicians, single trade. Yuman for all operations and invoicing, with a structured accounting export to your accountant or to a lightweight accounting package. No ERP at all. This is the most common case, and also the fastest to implement. For budget orders of magnitude, see how much a CMMS costs.
- Group, or a mix of maintenance + trading + projects. The ERP keeps accounting, payroll, purchasing and consolidation. Yuman carries the entire maintenance flow and pushes sales documents up. The two systems talk to each other in real time via the documented REST API (the technical interface that lets two applications exchange data) and webhooks (automatic notifications sent to the ERP as soon as something happens in Yuman, for example an invoice being approved). Each system stays master of its own domain: the field in the CMMS, accounting in the ERP.
Connectors already exist for the main accounting systems on the market. Integration is no longer the risk item it was ten years ago.
Three questions to ask before you sign
Whoever the candidate is, ask the same three questions. They do the sorting for you.
1. "Show me the mobile app, in airplane mode." Ask the vendor to switch off the phone's connection during the session, then pull up an asset's history, fill in a report, take a photo, capture a signature, and reconnect to sync. That is a thirty-second demo. Many modules fail this test.
2. "Demonstrate the full flow, without switching screens or tools." Customer request, quote, signature, work order, scheduling, mobile execution, invoice, payment chasing. End to end, on the same database, with the same data. If the demo breaks off with "that part is handled in the finance module" or "that point would be covered by a custom development", you have your answer.
3. "How many of your customers are maintenance contractors like me?" Not manufacturers doing in-house maintenance: companies that invoice their work to third parties, of your size, in your trade. Ask for three referenceable customers you can call. The number, and the precision of the answers, tell you more than any feature matrix.
Choose the tool built for your business
The real trade-off is not between a large general-purpose system and a small specialised tool. It is between a system that already knows your value chain and a system you will have to teach it to, line of code by line of code. For a maintenance contractor, the vertical CMMS is the core system, and the ERP — where one is needed — is the accounting complement. Not the other way round.
See it for yourself before you launch your tender. Request a demo: we'll walk you through the full flow, from quote to invoice, in 45 minutes.