Business portfolio analysis is a technique that analyzes a company's different business units or products in the same way an investment portfolio is analyzed. It uses tools like the BCG matrix and GE nine-cell matrix to evaluate business units based on factors such as market share and market growth. This helps companies allocate resources more effectively by identifying strong business units in attractive markets that should receive more investment, and weak units in unattractive markets that may need to be improved or divested. While portfolio analysis provides a systematic approach and encourages strategic evaluation, the analyses can oversimplify strategies and produce static snapshots that may not account for changing market conditions.