A Practical Formally-Based Modelling Method for Object Oriented Information Systems

Most of the popular modelling methods that have been used for object oriented information systems are informal, and their use seems to impose certain limits that are difficult to overcome. Firstly, informal methods tend to produce low-quality models. For example, Hayes and Coleman has shown in [5] that the OMT models of Rumbaugh method are ambiguous, incoherent and incomplete. Secondly, informal methods also tend to lead to ineffective modelling processes. The problem can often be traced ultimately to the informal characteristics of the model. Essentially, an imprecise model cannot effectively alert the analyst as to what kinds of information to look for and what kinds of problems to consider; nor does it provide a suitable framework to record all the relevant information obtained during the modelling process.