In Half Life Forster documents a detailed study of corporate survival trends, and examines and extends the existing landscapes, tools, models and indexes used to monitor the corporate life cycle. Forster goes on to describe the creation of a new business fitness landscape model, introduces two new business risk parameters, creates a new business diversity fitness index, and completes a macro analysis of the extinction rates associated with the 100 largest corporations in the United States. With these new tools Forster establishes a new model for viewing the mean life and half life of large corporations and for studying the impact that related and unrelated diversification in industry participation has on a corporation's effective lifespan. Forster suggests that established corporations don't survive just by being the fittest, but that they survive rapid discontinuous change by finding a new optimum position in a new business fitness landscape.