13Pp
Column 1 · Strategy and Positioning · Era 2, Planning (1970s)
Portfolio Planning
Formulation, content · Major · Cluster I, Strategic Choice
Description
Day evaluated product portfolio models such as the growth-share matrix as tools for allocating resources across business units and diagnosed the assumptions and limits of these planning devices.
Managerial Implications
Run the business as a portfolio: some units generate cash, some need investment, and some should be exited. Use a simple matrix of market attractiveness and competitive strength to make the allocation explicit and to stop every unit from claiming growth funding. The discipline matters more than the tool; the risk is treating a classification as a decision rather than as the start of one.