Dealing with Cost Estimation in Software Product Lines: Experiences and Future Directions

After 5 years invested in developing accurate cost estimation tools, Rolls-Royce has learnt about the larger potential of the tools to shape many aspects of the business. A good estimation tool is a "model" of a project and is usually used to estimate cost and schedule, but it can also estimate and validate risks and opportunities. Estimation tools have unified engineering, project and business needs. The presence of good estimation tools has driven higher performance and stability in the business. It was evident we needed this capability to underpin decisions in our new Software Product Line strategy. The objective of this paper is twofold. First, we report the experiences gained in the past on the use of estimation tools. Second, we describe the current efforts and future directions on the development of an estimation tool for Software Product Lines. At the heart of the Product Line estimation tool is a simple representation of the product - represented as the number of Lines Of Code (LOC). The next generation of tool, will need to consider wider aspects of product quality in order to create more accurate estimates and support better decisions about our products.