This paper describes and illustrates a procedure developed for analyzing the impact on future capacity requirements and SO/sub 2/ emissions that results from changes in the planned retirement dates of electric generating units. Because of the complexity of these considerations, the approach described in this paper for analyzing retirement/refurbishment decisions is based on exogenously supplied information about changes in expected unit lifetimes. While detailed unit-specific information can be represented, the developed approach is based on generic representations and lifetimes to allow the broad implications of refurbishment strategies to be examined. 5 figures.