This document discusses master data and structures in Profitability Analysis (CO-PA). Master data provides the fundamental data and defines characteristics and value fields that determine profitability segments. Structures are created by defining characteristics, value fields, and operating concerns. Master data consists of individual characteristic values that specify valuation levels through their combination into profitability segments. The document describes how profitability segments, characteristics, characteristic values, and structures are related and integrated in CO-PA. It also discusses valuation methods like using material cost estimates, conditions, costing sheets, and customer exits that are used to determine values in profitability segments.