Establish the business case for the system and delimit the project scope, identify all external entities with which the system will interact and define nature of this interaction at a high-level. Identify all use cases and describe architecturally significant ones. The business case includes success criteria, risk assessment, and estimate of the resources needed, and a phase plan showing dates of major milestones.

Analyze the problem domain, establish sound architectural foundation, develop the project plan, and eliminate the highest risk elements of the project.  Architectural decisions considering the system wide scope, functionality and nonfunctional requirements such as performance requirements. In the elaboration phase, an executable architecture prototype is built in one or more iterations, depending on the scope, size, risk, and novelty of the project. This effort should at least address the critical use cases identified in the inception phase, which typically expose the major technical risks of the project.

During the construction phase, all remaining components and application features are developed and integrated into the product, and all features are thoroughly tested. The construction phase is, in one sense, a manufacturing process where emphasis is placed on managing resources and controlling operations to optimize costs, schedules, and quality. In this sense, the management mindset undergoes a transition from the development of intellectual property during inception and elaboration, to the development of deployable products during construction and transition.

The outcome of the construction phase is a product that is integrated on the adequate platforms and meets the operational capability, a product ready to put in hands of its end-users with necessary user manuals.

The transition phase is entered when a baseline is mature enough to be deployed in the end-user domain. This typically requires that the usable set of the system has been completed to an acceptable level of quality and that user documentation is available so that the transition to the user will provide positive results for all parties.