This chapter provides two kinds of background information that we consider important to the subject area. First, we surveyed the supply chain management, operations management, and management science literatures for those works contacting life-cycle issues and at the same time that use quantitative or modeling approaches. We then developed synoptic summaries of these publications and provide some analysis of their central topics, trends, and themes. Hopefully the results will be a helpful reference guide to the related literature to date for both practicing managers and researchers. In the second part of the chapter, we introduce the standard quantitative methods and models used for mathematical life-cycle models. These have been developed under the label of diffusion models and most of the work has been carried out by marketing scientists. This topic should be useful to practitioners in making forecasts, constructing estimates related to capacity, and other supply chain management forecast and planning issues. We also note that some research needs in this area.