Design cost centres, budgets and rules

Set up — Procurement & Approvals.

Structure it once, properly. The decisions here are the expensive ones to change later.

The order matters. Cost centres first, because everything else points at them. Budgets next, on the cost centres that need controlling — not on all of them. Then the approval rules that give the budgets teeth, then the per-person limits that decide how much ordering never reaches an approver at all. Finally, hand the whole thing to the customer's own admin, because their organisation chart changes and yours does not.

Two decisions here are hard to reverse: the cost-centre codes, which have to match the customer's ERP exactly, and whether a limit blocks or routes. Get those from the customer in writing before you configure anything.