Possible UMLBased Size Measures

Why do we size software? For many reasons. To estimate effort. To estimate memory requirements. To estimate processing or execution speed. This paper considers size measures that help us predict the effort needed to design, build and test computer software using object-oriented methods. The Unified Modeling Language (UML) is emerging as an industry standard for recording the results of object-oriented analysis and design. We focus specifically on the use of the products of the UML as early reliable measures of software size. These products include use cases, class diagrams, state diagrams, event trace diagrams, etc. There are too many UML products to use them all. Thus, we identified a subset suitable for early estimation of effort by examining the development process. The process determines the activities performed by the development staff, and so the sequence in which the products are generated. This enabled us to identify which products will be available early in a project. We estimate the size by combining estimates for the three aspects of software: data, control behavior, and function, as identified by [DeMarco, 19821. We examined the elements of UML notation, and the activities of the Object-Oriented Systems Analysis (OOSA) method. This metho