Revenue Concentration & Pareto Analyzer

Revenue is supplied historical line-item amounts, in one currency. Repeated lines in the same order sum; orders count distinctly per customer. Dates must be ISO calendar dates. Positive spend is required for concentration. RFM ties receive equal scores using midrank bands; no predictions or causal claims. Basket analysis deduplicates products per order and examines pairs, at most 100 products and 2,000 baskets. Inputs stay in browser memory. No workbook is created. Table limits: 5 MB total text, 25,000 rows, 64 columns and 200,000 cells; expensive operations have stricter limits. Processing can be cancelled.