01. Two tools, two directions
A CRM — customer relationship management — follows what happens before a sale and around it: leads, opportunities, follow-ups, the history of exchanges, quotes sent. It answers “where do we stand with this customer”.
An ERP — enterprise resource planning — follows what happens once the sale is closed, and everything that makes it possible: purchasing, stock, production, invoicing, accounting. It answers “what comes in, what goes out, and what does it cost us”.
The overlap sits at the boundary: the quote and the invoice belong to both worlds. That is exactly where the two systems must talk, or the same order gets entered twice.
02. Which one to start with
The right answer is not theoretical: start with the one whose disorder costs you most today, and you already know which that is.
If deals are lost because a follow-up was forgotten, if a customer’s history leaves with the salesperson who leaves, if nobody can state the month’s forecast without rebuilding a spreadsheet, the CRM is what is missing.
If your stock on file does not match the shelf, if a product’s margin requires an investigation, if invoicing retypes what sales already recorded, it is the ERP.
Many companies only need one of the two, for a long time. Buying both because they are sold together doubles the budget, the timeline and the training load, for value that only arrives on one of the two fronts.
03. Connecting them rather than replacing everything
If you already own one of the two and it works, replacing it to get a homogeneous suite is rarely worth it. A well-built connection between the two costs less than a migration, and preserves habits already learned.
What has to flow is limited and known: the customer record, the accepted quote, the issued invoice, the payment received. A clear flow on those four objects is enough to remove double entry, which is the real problem.
- The customer record, created once and shared.
- The accepted quote, which becomes an order without retyping.
- The issued invoice, visible from both sides.
- The payment received, which closes the opportunity.