Direct answer
Define the commercial unit first
Put the quantity, price basis, time period, and included costs at the top of the worksheet. A correct formula still gives the wrong business answer when pieces, M, impressions, cases, orders, or annual volume are mixed.
- Make the assumption for forecast variance visible.
- Make the assumption for safety stock visible.
- Make the assumption for stockout vs excess visible.
- Make the assumption for obsolescence visible.
Use scenarios, not a universal benchmark
Run the current state and proposed state with buyer-supplied inputs. Then change one assumption at a time so the decision-maker can see which inputs drive the result.
Example: If a quote changes quantity basis, freight treatment, or order cadence, preserve both versions instead of overwriting the first comparison.
What the number leaves out
Keep technical equivalence, quality risk, approval effort, inventory exposure, service, change control, and operating fit beside the calculation. A modeled saving is not a supplier recommendation or guaranteed outcome.
Boundary: This page organizes buyer and project information. It does not approve a film structure, gauge, barrier target, seal condition, food-contact position, shelf life, recyclability claim, machine setting, or supplier for a specific application.
Related work
See something that needs correcting? Tell Matt.