During the Base Architecture phase you specify requirements in greater detail and develop the base architecture in sufficient detail to reduce re-work on an iterative development. Emphasis shifts now to prioritizing requirements and completing their detailed specification, analyzing them, designing a solution to satisfy them.

To prove the architecture you may implement and test an "end-to-end skeleton" of working code that supports the high-risk use cases for your system. At the end of this phase you hold a review where the project architect and stakeholders assess the state of the project and agree:

• Project vision has stabilized and is realistic
• The requirements for the project can be met
• Architecture is stable and sufficient to satisfy the requirements
• Current expenditures are acceptable and reasonable estimates have been made for future costs and schedules
• Project team has a realistic chance to succeed
• Detailed plans for the next few Build Solution iterations are in place

Phase starts when the Business Case is approved.

• to develop the architecture design
• to produce a plans for following Build phase project management stages
• to detail all use cases
• to start to create program/configuration specifications or test scripts (depending on development approach)
• to start to create interface definitions
• to start to develop the test plans (Unit, Integration, Regression and Acceptance)

Main deliverables of the phase are:

• Component Model
• Nodes and Connections Model

Work products that may be used during the phase include:

• Use Cases
• Business Process Model
• Test Plans
• Prototypes (which may require program specifications, test scripts or configuration specifications)
• Project Management Documents

The phase ends when sufficient work has been performed to understand the E2E design of the solution and prevent major rework if multiple iterations of development are required and when the project architect has approved the design. To understand if sufficient design detail has been achieved, the baseline solution should be sufficient to obtain a fixed price development contract with minimum uplift for risk if a 3^rd party was contracted for the development.

The following quality management activities need to be performed:

• Peer inspection of any deliverables (E.g. Fagan inspection method )
• Architecturalapproval of the design
• Test Manager (where existing) approval of test plans
• Quality review of any test plans
• Security approval of design
• Phase end checklist