Patterns: Implementing Self-Service in an SOA Environment

Chapter 5. Product mappings and product overview 97

Rational Software Architect provides the tools needed to create design patterns.

When developers recognize repeatable structures or processes they can create

patterns from them, allowing others to use these designs.

Patterns are stored in a RAS repository as a unique type of reusable asset in the

form of a plug-in. Users can browse the repository for useful patterns as they

model systems. The pattern user relies on the pattern documentation for

information about selecting and applying a pattern. Depending on the pattern

design, the pattern applier has the flexibility to apply all or only part of a pattern

as needed.

A set of sample patterns is supplied with Rational Software Architect and can be

seen in the RAS perspective. Another set of patterns is included with the product

and can be installed as an example.

5.5.3 Modeling

UML modeling provides a way of architecting systems in such a way they can be

communicated to the stakeholders. UML models show a specific perspective of a

system. Models are visual representations and as such are easily verified and

communicated. Models start at the conceptual levels and can be refined down to

detailed levels. Rational Software Architect supports UML Version 2 (UML 2).

Rational Software Architect supports modeling through all phases of software

development.

1. Capturing system requirements

The first step in any system design is to determine the requirements for the

solution. The IBM Rational RequisitePro® solution is a requirements and use

case management tool. This tool can be integrated with Rational Software

Architect, allowing you to map existing requirements to existing UML model

elements. You can also create requirements from existing model elements, or

create model elements from existing requirements definitions. The result of

this development phase is one or more use case diagrams that describe how

the system will be used.

2. Domain analysis

The next step is to build on the use case model by describing the high-level

structure of the system based on the system domain requirements. An

analysis model is used to capture this information. The analysis model

consists of class diagrams that model the static structure of the system and of

sequence diagrams that model the interactions between participants. The

analysis model describes the logical structure of the system but does not

define how it will be implemented.