AbstractThis paper presents a technique called FCF (Formally specified Component based Framework development method) to develop frameworks by connecting components whose functional aspects are formally specified. In FCF, three rules are imposed on component extraction/design from the perspectives of the framework's hot spot and its algebraic specification. Then, on the basis of the rules, problems for specifying the functional aspect of a framework which is composed by connecting components are clarified, and these are solved by a descriptive device and a theoretical extension of algebraic specification. Then, using these solutions, the components of business transaction processing extracted and designed following the rules are specified, from which the solutions are evaluated. © 2003 Wiley Periodicals, Inc. Syst Comp Jpn, 34(8): 62–76, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10280