Plain definitions of the terms that appear in store operations, each with the calculation, a worked example and the mistake people make.
Operations vocabulary is mostly borrowed from warehousing and supply chain, where the terms have precise meanings and rather more infrastructure behind them than a six-person store has. That gap is where the confusion lives: the word is used correctly, and it means something the person using it cannot actually do.
Each entry gives the definition first, in one paragraph, then the calculation where there is one, then a worked example. The worked examples use invented numbers chosen to make the arithmetic clear. They are illustrations, not findings, and nothing here should be quoted as research.
The stock level at which you place the next order, derived from how fast it sells and how long it takes to arrive.
The buffer you hold for the times demand runs hot or the delivery runs late.
How many days your current stock will last at the rate it is actually selling.
The share of the stock you received that you actually sold in a given period.
The elapsed time from deciding to order to the stock being sellable, which is longer than any supplier quotes.
A third-party logistics provider: a company that holds your stock and ships your orders for you.
Counting a few stock lines regularly rather than counting everything twice a year.
The gap between the stock your records say you have and the stock actually there.
A written commitment to do something within a stated time, with a consequence if you do not.
A way of writing down who does the work, who owns the outcome, who gets asked and who gets told.
The written route a problem takes when the person who found it cannot resolve it alone.
A written procedure for a task that recurs, short enough that somebody actually opens it.