![]() |
![]() |
![]() |
![]() |
![]() |
Overview of the SOMT Method
The SOMT method provides a framework that shows how to use object-oriented analysis and SDL-based design together in a coherent way. The framework is based on describing the analysis and design of a system as a number of activities. Each activity deals with some specific aspects of the development process. The work done in the activities is centered around a number of models, that document the result of the activities. As an integral part of the SOMT method, guidelines are given for the transition between the different models. The activities and the main models used in SOMT are illustrated in Figure 613.
As can be seen in Figure 613, SOMT consists of five major activities:
- Requirements analysis. The purpose of the requirements analysis is to analyze the problem domain and the requirements on the system to be built, essentially by analyzing the system as a black-box in its intended environment.
- System analysis. The purpose of the system analysis is to identify the architecture and most important objects that must be represented in the system to achieve the required functionality.
- System design. The purpose of the system design phase is to precisely define the architecture of the system including the detailed interfaces between different parts. In the system design the architecture of the system is also analyzed in terms of implementation strategies and decomposition into work packages for different development teams
- Object design. The purpose of the object design is to define in detail the functionality including the behavior of all objects.
- Implementation. The purpose of this phase is to create the executing application that implements the requirements.
As seen above, SOMT uses a number of different models to describe different aspects of the system. In many cases there are relations between objects in the different models. One especially important relation is that in some cases one object can be seen as an implementation of another object. In SOMT this type of relation is called implink (short for implementation link) and corresponds to a design decision taken during the development. The creation and maintenance of implinks forms an important part of the SOMT method. Two points can be made:
- Since the transition between different models is a creative process involving a number of engineering decisions, this is a manual, but tool supported, activity.
- The major tool support is a Paste As functionality that will allow you to copy an object in one model and paste it into another model while automatically creating an implink. For example: an object model class from the analysis object model may be pasted as an SDL process type in the system design model.
Note that the Paste As functionality can be seen as an implementation of transformation rules between the different models, e.g. from object models to SDL design models.
Another important aspect of implinks is that they facilitate consistency checks between the different models.
It is important to note that even though the description in SOMT of the different activities is a sequential description, this does not mean that in practice these activities can or should be carried out in sequential order. On the contrary, depending on the size and complexity of the application, the different activities can be organized in a number of different ways. This is the topic of the SOMT Projects.
http://www.ibm.com/rational |
![]() |
![]() |
![]() |
![]() |