Cost Reporting Elements and Activity Cost Trade-offs for Defense System Software. Volume II. Executive Summary.

This technical report examines the costs of developing and maintaining computer software for major defense systems. A process model is described which depicts the relations among activities and phases of the software life cycle, identifies the product and cost information that is normally available, and specifies the milestones. This process model is normally used as the basis for selecting the elements of a software cost reporting system. The suggested reporting system also includes descriptions of the final product, time phasing of product development, a standardized list of Computer Program Components, and a standardized list of labor categories. During the study, data was collected from several sources including the following Air Force organizations Electronic Systems Division, Aeronautical Systems Division, Space and Missile Systems Organization, and Data Systems Design Center. Cost estimating relationships for each phase of the software life cycle are explored, using the process model and the data. The importance of trade-offs in cost between phases is demonstrated. The report also contains estimating relationships for evaluating the cost effects of software size, computer capacity constraints, programming language, and changes in requirements. It also addresses the separation of two activities, error correction and product improvement, during the maintenance phase of the life cycle. Results are integrated with other software cost estimating techniques. Author