Implementing an ERP: what it delivers and what it leaves out

An ERP — an integrated management system — brings together in one place what used to live in a separate program per department: accounting, invoicing, purchasing, inventory, production, and often sales.

The underlying advantage is not having more features: it is that the same piece of data stops existing in three places. And the underlying disadvantage is that an ERP does not cover everything well, and it is worth knowing what it leaves out before discovering it halfway through the project.

What it delivers

A single master of clients and items. No more duplicates with two codes, which break every report and send invoices to the wrong entity.

The complete economic cycle. From order to invoice to payment, with no manual gaps.

Accounting traceability. Every movement backed by its record, which is what lets you close a fiscal year without reconstructing anything.

Aggregated information. Being able to look at the whole company instead of adding up departmental spreadsheets.

The three criteria when choosing one

That it be comprehensive, able to cover the areas without leaving gaps that get patched with spreadsheets. The practical test: how many times a new client gets typed in from the moment they arrive to the moment they are invoiced. If it is more than once, it is not that comprehensive.

That it be modular, so it can be implemented in stages. And here is an uncomfortable and revealing question: what happens when you need something that is in another module. If the answer is a contract extension every time, the real cost is not the one in the initial quote.

That it be open. That it allows connecting to what you already have and to what is coming. It is the criterion that most determines the cost of the next five years.

There is a longer piece on criteria for choosing an adaptable ERP.

What an ERP does not cover well

And not out of neglect: it is simply not its domain. Specifically, four things about maintenance.

The asset record as a history. Not the item purchased, but the equipment installed: where it is, what serial number it has, what has been done to it, what anomalies remain open, and how much it has cost so far.

Frequency. An ERP does not generate the six-monthly inspection of two hundred pieces of equipment on its own, nor check whether the due date falls on a holiday or whether the technician is on vacation. And it does not account for wear depending on a counter — hours, cycles, kilometers — instead of the calendar.

Field work. This is the clearest gap. ERPs are built for an office, and maintenance happens on a rooftop, in a basement, or in a warehouse without coverage.

The relationship with whoever receives the service. Who reported it, with what priority, what was promised, and what can be proven afterward.

Where maintenance fits, then

As a piece that coexists with the ERP, not one that competes with it. The boundary is agreed before connecting anything:

The ERP governs clients, items, and pricing. The CMMS governs assets, interventions, and consumption.

It makes sense if you think about where each thing is created: a new client is created in the sales process; a spare part consumption is created when a technician opens the box.

With that boundary clear, the flow organizes itself. Master data comes from the ERP; toward the ERP go closed work orders with their hours and material, which is exactly what it needs to invoice.

What to ask about integrations

“Does it integrate with X?” does not work — the answer is always yes. What matters is what data travels, and in which direction.

Not every connector does the same thing. GMAO Cloud’s integrations catalog lists the scope of each one, and it is worth demanding that level of detail from any vendor: for example, Sage X3 imports clients, addresses, and items but does not export work orders.

And if your system is not on any list — the most common case — what matters is that generic channels exist: REST API, SOAP, direct database access, and CSV and FTP exchange.

The order of the projects

The practical question when you need to do both: ERP first, or maintenance first?

ERP first if the problem that hurts most is the economic cycle: slow invoicing, duplicates, impossible closings.

Maintenance first if what hurts is operational: missed inspections, inventory that does not add up, being unable to prove what was done, clients who call to ask. And especially if there is a regulatory obligation involved, because legal maintenance rests on the work order history, checklists, and documentation with their dates.

What almost never works is doing both at the same time. They are projects that compete for the same people.

What gets underestimated in an ERP project

Three line items that always show up and are almost never in the initial estimate.

Data cleanup. Migrating clients and items with duplicates, inconsistent codes, and empty fields only moves the problem elsewhere. That work is done by the company, not the vendor, and it is usually what sets the real go-live date.

Processes nobody had written down. An ERP forces you to decide who does what and in what order. Where that was not agreed, the project stalls until someone agrees on it, and that is not a technical delay.

Temporary coexistence. For months, the old system and the new one live side by side. It is the phase where the most mistakes happen and the one most often left out of planning.

The same applies, on a smaller scale, to a maintenance rollout: the big line item is not the software, it is the work of getting the data and the processes in order.

What not to do

Migrating the ERP in order to do maintenance. It is expensive, has a long learning curve, and puts the invoicing cycle at risk. If the ERP works, the sensible move is to leave it alone and add the piece it is missing.

Syncing everything in both directions. Start by bringing in clients and items and sending closed work orders. Add the rest only once that has been running for months without anyone needing to look at it.

Expecting real time. It is almost never necessary. Having closed work orders arrive every night is usually enough, and much cheaper to maintain.

If you want to see how it would fit with your current ERP, you can write to us or request a demo.