Core Concept:  The graph quantifies the cost of a solution (vertical axis) and the likely hood that it will be implemented in the future (horizontal axis).  Solutions that are cheap regardless of their certainty have a higher tendency to be implemented (Q2&Q4 – ‘good buys & ‘cheap tricks’).  Expensive solutions must have a very high-level of certainty in order to be implemented (Q1 – ‘life-savers’).