Ask a procurement team what they saved last year and you will get a number from the sourcing pipeline. Ask finance and you will usually get a smaller one. The difference is not dishonesty on either side — it is that the contract and the spending happen in different places, run by different people, measured differently.
Where value leaks
Leakage concentrates in a few predictable places: buying outside the agreement because the catalogue is awkward, price lists that were never loaded into the ERP, indexation clauses nobody is tracking, and volume tiers that are never claimed because nobody aggregates across business units.
Handover is a process, not an email
The moment a contract is signed it stops being a sourcing artefact and becomes an operational one. If no one owns loading the rates, briefing the requisitioners and setting the review date, the agreement will be honoured only where someone happens to remember it.
Measure what was spent, not what was agreed
A savings number sourced from the negotiation is a forecast. Reconciling against actual invoiced spend is harder, produces smaller numbers, and is the only version worth reporting. Teams that make the switch usually find their credibility with finance improves even as the headline falls.
Make the review calendar real
Most contracts contain a mechanism — a benchmark, a rebate, a service credit — that goes unused. A simple calendar of what can be claimed and when, owned by a named person, recovers more value in most organisations than the next sourcing wave.