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2.4 The Rational Unified Process 51

Phase Iteration

Figure 2.12 Phases in
the Rational Unified
Process Inception Elaboration Construction Transition

interact with the system and define these interactions. You then use this infor-
mation to assess the contribution that the system makes to the business. If this
contribution is minor, then the project may be cancelled after this phase.
2. Elaboration The goals of the elaboration phase are to develop an understanding
of the problem domain, establish an architectural framework for the system,
develop the project plan, and identify key project risks. On completion of this
phase you should have a requirements model for the system, which may be a set
of UML use-cases, an architectural description, and a development plan for the
software.
3. Construction The construction phase involves system design, programming, and
testing. Parts of the system are developed in parallel and integrated during this
phase. On completion of this phase, you should have a working software system
and associated documentation that is ready for delivery to users.
4. Transition The final phase of the RUP is concerned with moving the system
from the development community to the user community and making it work in
a real environment. This is something that is ignored in most software process
models but is, in fact, an expensive and sometimes problematic activity. On
completion of this phase, you should have a documented software system that is
working correctly in its operational environment.

Iteration within the RUP is supported in two ways. Each phase may be enacted in
an iterative way with the results developed incrementally. In addition, the whole set
of phases may also be enacted incrementally, as shown by the looping arrow from
Transition to Inception in Figure 2.12.
The static view of the RUP focuses on the activities that take place during the
development process. These are called workflows in the RUP description. There are
six core process workflows identified in the process and three core supporting work-
flows. The RUP has been designed in conjunction with the UML, so the workflow
description is oriented around associated UML models such as sequence models,
object models, etc. The core engineering and support workflows are described in
Figure 2.13.
The advantage in presenting dynamic and static views is that phases of the devel-
opment process are not associated with specific workflows. In principle at least, all
of the RUP workflows may be active at all stages of the process. In the early phases
of the process, most effort will probably be spent on workflows such as business
modelling and requirements and, in the later phases, in testing and deployment.