IBM SG24-7368-00 manual Additional design points

Separation of concerns

Separation of concerns allows developers to address each set of stakeholder concerns independently.

Integration

Integration is achieved by requiring the use of a common set of design elements across multiple sets of concerns.

System decomposition

System decomposition subdivides the system by structure, rather than by function, enabling the framework to provide levels of structure that enable parallel development.

Scalability

Scalability is achieved by using the same framework, whether the system under construction is an enterprise or a product component or anything in between.

This last point gives MDSD great power and elegance—we can use it to reason effectively about any system, from organization to product component. It dispenses with artificial complexity introduced by having a different methodology at each level, and identifies powerful abstractions common to each. It creates a methodology that is easily internalized by practitioners and applicable to many domains.

Additional design points

The design of MDSD is also intended to:

￿Apply the RUP framework to systems development

￿Employ the appropriate semantics and modeling languages

￿Provide tool assets

￿Maintain all model levels as program assets

Let us now take a look at each one.5

Apply the RUP framework to systems development

The RUP life cycle and disciplines are shown in Figure 2-2.MDSD follows the RUP in these ways:

￿Life cycle: Focusing on removing risks, MDSD follows RUP's four phases by leveraging the team's evolving understanding of the project details.

5The following material is adapted from Cantor, Rational Unified Process for Systems Engineering, The Rational Edge, August 2003.

22Model Driven Systems Development with Rational Products