A supplier comparison is a moving object. A revised offer arrives, a quantity changes, and someone corrects the delivery condition. The working document should accommodate those changes. The decision record needs to preserve what was actually compared.

That distinction shaped an internal procurement implementation documented in my public portfolio. This article discusses its anonymized design pattern. It introduces no new deployment or measured purchasing benefit.

The central question is simple: when someone revisits a purchase decision, can the system show the evidence and assumptions that existed when the choice was made?

Give the objects different lifecycles

The original supplier document, normalized offer, working comparison, and decision snapshot serve different purposes.

The document records what the supplier provided. Normalization records an interpretation: which number is the unit price, which unit applies, and what conditions accompany it.…