Units of measure

Buy in cases, hold in eaches, sell in either — with one conversion definition doing the arithmetic.

Inventory → Units of measure.

An item has a base unit — the unit stock is held and costed in. Around it you define related units with a conversion: 1 case = 24 each, 1 pallet = 40 cases.

Then set defaults: a purchasing unit, a stocking unit and a selling unit. A PO in cases receives 24 eaches per case; an invoice in eaches relieves the right quantity; the valuation stays in the base unit throughout.

Why not just do the maths yourself: because a mis-keyed conversion on a receipt is a costing error that survives every subsequent transaction. Defining it once means it can only be wrong once.

Conversions must be exact — a unit that does not divide evenly into the base is rejected rather than rounded.