FOOM methodology

Users' requirements of an information system are modeled in the analysis phase of the development process. The requirements can be modeled with various modeling methods. In this study we compare two alternative methods for modeling the functional requirements: one is the UML Use Case (UC) model; the other is OO-DFD transactions (Object-Oriented DFD is a variant of DFD that includes data classes rather than "traditional" data stores). Each of these modeling methods consists of diagrams accompanied with narrative, semi-structured descriptions explaining their details. We conducted a controlled experiment that compared the comprehension of the two models (i.e., the diagrams and their descriptions) of a certain system, and the quality of models created for a certain system with each of the two modeling methods. The main results of the experiment are that models created with the UC method are of better quality than models created with the OO-DFD transactions method because the former are simpler and less detailed; creating highly-detailed models are error-prone. Interestingly, in spite of the difference in the level of detail and structure, the experiment reveals no significant difference in comprehension of models of the two methods. The results call for improvement of the modeling methods in a way that considers the advantages of each of them; and thus we propose an improved method sketch that we call Enhanced Use Case (EUC), which will be evaluated in future work.

The software analysis process consists of two main activities: data modeling and functional modeling. While traditional development methodologies usually emphasize functional modeling via dataflow diagrams (DFDs), object-oriented (OO) methodologies emphasize data modeling via class diagrams. UML includes techniques for both data and functional modeling which are used in different methodologies in different ways and orders. This article is concerned with the ordering of modeling activities in the analysis stage. The main issue we address is whether it is better to create a functional model first and then a data model, or vice versa. We conduct a comparative experiment in which the two opposing orders are examined. We use the FOOM methodology as a platform for the experiment as it enables the creation of both a data model (a class diagram) and a functional model (hierarchical OO-DFDs), which are synchronized. The results of the experiment show that an analysis process that begins with data modeling provides better specifications than one that begins with functional modeling.