As stated earlier, work flows are sequences of related activities performed by specific roles. UP defines five core workflows in its life cycle:

1.    Requirements: Figuring out (from the customer) what the system should do.

2.    Analysis: Refining, elaborating and describing in utmost detail the requirements collected from the requirement workflow.

3.    Design: Planning the system architecture to reflect the requirements of the customer.

4.    Implementation: Coding and development of the software.

5.    Test: Verifying the quality of the product to be delivered.

The project life cycle in UP is divided into four phases (They are described in more detail in the next section):

1.    Inception: During the inception phase the requirements are gathered and analyzed and the functional and non-functional needs are established. Technical proofs of concepts are conducted and details of the hardware infrastructure and software architecture are drafted.

2.    Elaboration: During the Elaboration phase detailed analysis of the requirements is made and the solution is designed. Tests plans are built.

3.    Construction: During the Construction phase the actual solution is developed. This involves software development, but also specification & development of the test data and finally tests executions.

4.    Transition: During the Transition phase the solution is rolled out to a limited number of users, piloted and enhanced if need be. Then it is rolled out to all the end users.

Phases and Workflows in Iterations -- Bring it together

Figure 1 best describes the essence of UP. As you can see, in the row headers we have the UP phases, in the column headers we have the UP workflows, and in the row footers we have the iterations planned throughout the project. The curves determine the relative amount of work needed in each phase throughout each workflow.

Figure 1

As you can see, one phase can have multiple iterations. For example, you can see that the inception phase is mostly concerned with requirements, where as the elaboration phase is more into analysis and design with a hint of implementation. The interesting curve is the testing workflow. As you can see, this curve spikes in every phase. Hence, we can conclude that testing is involved in all phases of UP, ensuring worthwhile quality.