The primary objective of this study was to develop an electrical aging model for XLPE cables aged at room temperature in air. A model successfully describing various experimental results on films and cables is presented within this report. The basic parameters involved in the model are explained, and difficulties associated with data interpretation are discussed. Another objective was to relate breakdown and electrical aging. It is shown that there is indeed a relation between the two processes, and the parameters influencing the relationship are indicated. It appears that statistical analysis of breakdown data is crucial for a coherent and useful interpretation of such data. With care and attention, it seems possible to reliably extrapolate fast breakdown results obtained under high fields to long life under low fields. Several experimental difficulties and pitfalls are noted, as well as some work that remains to be done in order to better simulate actual cable operation in service.