Rank Busy Product Groups Within Each Customer

How it behaves

Use this when the user asks which product groups contribute the most sales or quantity for every customer, a set of customer ledgers, or a customer group, without making one call per customer. It performs server-side dense ranking within each customer and period partition and returns complete-customer contribution. Use busy_analyze_customer_product_group_sales instead when the question concerns one customer and needs zero-sale groups or previous-period growth. This tool is ledger-level and does not provide canonical cross-company, gross-profit, collections, branch, territory, or salesperson analysis.