Senior consultants, not slide decks
Ask exactly who will be on your project — by name. Ask about their personal Sage X3 history. Insist that the team in the sales meeting is the team that will do the work. The largest single predictor of Sage X3 project success is who is actually staffed on it.
Real references in your industry and size
Talk to two or three reference customers in your industry and revenue band. Ask them what went wrong and how the partner handled it. Every project has problems; what matters is the response.
Methodology you can read
Ask for written methodology — discovery, design, build, test, train, go-live, hypercare — with deliverables you would actually use. Vague 'agile-ish' approaches are a red flag in ERP implementations.
Honest timelines and pricing
If a Sage X3 implementation timeline sounds too short to be true, it is. Mid-market implementations almost always run 6–12 months. A partner offering significantly less is either underestimating or planning to invoice change orders.
Cultural fit and direct communication
You will work with these people for a year. They will be in your finance team, your warehouse, your IT team. Pick partners who give you direct, honest answers — including the answers you don't want to hear.