-Estimation of Software Size and Effort Distributions

All too frequently, a software cost estimate is required in the early stages of the life-cycle when requirements and design specifications are immature. To produce a cost estimate under these conditions requires extensive use of expert judgment and addressing significant estimation uncertainty. Research has shown that expert judgment under the right conditions can yield relatively "accurate" estimates [Hihn & Habib-agahi, 19901. Unfortunately, most expert judgment-based estimates do not meet these conditions and frequently degenerate into outright guessing. Especially, when the estimate is made without the assistance of a cost estimation professional. At its best, expert judgment is a disciplined combination of a best guess combined with historical analogies. Using the method of paired-ratio comparison matrices provides a formal systematic way to extract, combine, and capture expert judgments and how they relate to analogous reference data [Saaty, 19801. A version of which is supported by the SEER-SSM (Software Sizing Model) tool. which is primarily advertised as a tool for estimating software size but can be used to estimate virtually anything requiring expert judgment [Bozoki, 19931.