COSMIC Approximate Sizing Using a Fuzzy Logic Approach: A Quantitative Case Study with Industry Data

In software engineering, the standards for functional size measurement require that the functionality to be measured be fully known for accurate measurement results. Therefore, in the early phases of software development, when there is a lack of detail, approximate sizing approaches must be used instead of the standards themselves. Approximate sizing techniques are typically based on the analysis of historical data of the functional size of a number of completed projects within an organization. For organizations without historical data on the functional size of their completed projects, this paper proposes a fuzzy logic model to approximate functional size early in the software development process. It also reports on a quantitative case study of this approximation technique from industry, and compares its performance with the Equal Size Band approximation approach.