This paper assumes that the establishment of requirements for software intensive systems is a two stage process: (i) a business analysis, to identify opportunities for business improvement; followed by (ii) a computing- oriented analysis to identify and define where computing facilities might support that business improvement. With that assumption, the remainder of the paper is concerned with investigating the resulting problem of integrating business analysis and computing analysis to provide an effective overall analysis procedure. In particular, the paper considers the integration of Soft Systems Methodology (SSM), a behaviour based business analysis technique, and Object-Oriented Analysis, specifically, Shlaer-Mellor Object-Oriented Systems Analysis (OOSA). The experimental use of the resulting technique on a generic billing system project in British Telecom is also discussed briefly.