Formalization & Data Abstraction During Use Case Modeling in Object Oriented Analysis & Design

摘要

In object oriented analysis and design, use cases represent the things of value that the system performs for its actors in UML and unified process. Use cases are not functions or features. They allow us to get behavioral abstraction of the system to be. The purpose of the behavioral abstraction is to get to the heart of what a system must do, we must first focus on who (or what) will use it, or be used by it. After we do this, we look at what the system must do for those users in order to do something useful. That is what exactly we expect from the use cases as the behavioral abstraction. Apart from this fact use cases are the poor candidates for the data abstraction. Rather the do not have data abstraction. The main reason is it shows or describes the sequence of events or actions performed by the actor or use case, it does not take data in to account. As we know in earlier stages of the development we believe in ‘what’ rather than ‘how’. ‘What’ does not need to include data whereas ‘how’ depicts the data. As use case moves around ‘what’ only we are not able to extract the data. So in order to incorporate data in use cases one must feel the need of data at the initial stages of the development. We have developed the technique to integrate data in to the uses cases. This paper is regarding our investigations to take care of data during early stages of the software development. The collected abstraction of data helps in the analysis and then assist in forming the attributes of the candidate classes. This makes sure that we will not miss any attribute that is required in the abstracted behavior using use cases. Formalization adds to the accuracy of the data abstraction. We have investigated object constraint language to perform better data abstraction during analysis & design in unified paradigm. In this paper we have presented our research regarding early stage data abstraction and its formalization.