A company's strategy evolves from one version to the next because of the importance of keeping the company's business model fresh and up-to-date. ongoing turnover in the managerial and executive ranks (new managers often decide to shift to a different strategy). changing management conclusions about which of several appealing strategy alternatives is actually best. pressures from shareholders to boost profit margins and pay higher dividends. the proactive efforts of company managers to improve this or that aspect of the strategy, a need to respond to changing customer requirements and expectations, and a need to react to the fresh strategic maneuvers of rival firms