How many weeks of history a small chain actually needs

Buyers sometimes arrive with a decade of monthly totals and almost no weekly file. Monthly totals hide Easter, hide a late delivery, hide a weekend market that stole Saturday.

For a chain of four to twelve stores we ask for weekly units, ideally two full years. One year can support a shorter horizon if the category is young — a new beauty counter, a shop that opened last March. Six months cannot support a twenty-six week apparel buy. We shorten the pages and write the limit on the first sheet.

Ten years of messy history is not a gift. Tills change. SKU codes get reused. A family called “blue” in 2018 is not the blue on the rail now. Cleaning that file would cost more than the study and still lie.

If a new store has no history, we treat it as a sibling of the closest shop in size and neighbourhood, and we print that sentence. The buyer can disagree. Disagreement belongs on the page, not in a hidden assumption.