We propose a methodology for information systems analysis and design which is a hybrid of two main streams in software engineering, the functional (or process-oriented) approach and the object-oriented (OO) approach. System analysis, which aims at eliciting and defining user requirements, continues to be carried out in the functional approach, utilizing data flow diagrams (DFD). System design, which aims at designing the software, is carried out in the OO approach, yielding an object model that consists of an object schema and a behavior schema (i.e., methods and messages). The transition from the functional model (in the analysis stage) to the OO model (in the design stage) is enabled by the use of ADISSA methodology, which facilitates design of the object schema from DFD data stores, and design of the behavior schema from transactions, which by themselves are derived from the DFDs.