This document discusses defining business units and strategic business plans. It discusses segmenting broad product groups like shampoo into specific units based on factors like target markets, product types, and product-market characteristics. It provides examples of segmenting the shampoo market based on attributes like target customer groups (e.g. mothers, young women, men), product types (e.g. dandruff, dry scalp, ethnic), and defines assessable business units. Guidelines are outlined for determining whether to combine or separate business units based on factors like marketing skills, technology, distribution channels, and competitive positions. Finally, examples are given of how businesses like airlines could be defined through a product-market matrix.