Milestone: Lifecycle Architecture

At the end of the elaboration phase is the second important project milestone, the Lifecycle Architecture Milestone. At this point, you examine the detailed system objectives and scope, the choice of architecture, and the resolution of the major risks.

Evaluation Criteria

The project may be aborted or considerably re-thought if it fails to reach this milestone.

Artifacts

Essential Artifacts (in order of importance)	State at milestone
Prototypes	One or more executable architectural prototypes have been created to explore critical functionality and architecturally significant scenarios. See the note below on the role of prototyping.
Risk List	Updated and reviewed. New risks are likely to be architectural in nature, primarily relating to the handling of non-functional requirements.
Development Case	Refined based on early project experience. The development environment, including the process, tools and automation support required to support the construction team will have been put in place.
Project-Specific Templates	The document templates used to develop the document artifacts.
Tools	The tools used to support the work in Elaboration are installed.
Software Architecture Document	Created and baselined, including detailed descriptions for the architecturally significant use cases (use-case view), identification of key mechanisms and design elements (logical view), plus definition of the process view and the deployment view (of the Deployment Model) if the system is distributed or must deal with concurrency issues.
Design Model (and all constituent artifacts)	Defined and baselined. Use-case realizations for architecturally significant scenarios have been defined and required behavior has been allocated to appropriate design elements. Components have been identified and the make/buy/reuse decisions sufficiently understood to determine the construction phase cost and schedule with confidence. The selected architectural components are integrated and assessed against the primary scenarios. Lessons learned from these activities may well result in a redesign of the architecture, taking into consideration alternative designs or reconsideration of the requirements.
Data Model	Defined and baselined. Major data model elements (e.g. important entities, relationships, tables) defined and reviewed.
Implementation Model (and all constituent artifacts, including Components)	Initial structure created and major components identified and prototyped.
Vision	Refined, based on new information obtained during the phase, establishing a solid understanding of the most critical use cases that drive the architectural and planning decisions.
Software Development Plan	Updated and expanded to cover the Construction and Transition phases.
Guidelines, such as Design Guidelines and Programming Guidelines.	The guidelines used to support the work.
Iteration Plan	Iteration plan for the construction phase completed and reviewed.
Use-Case Model (Actors, Use Cases)	A use-case model (approximately 80% complete) - all use cases having been identified in the use-case model survey, all actors having been identified, and most use-case descriptions (requirements capture) having been developed.
Supplementary Specifications	Supplementary requirements capturing the non functional requirements are documented and reviewed.
Optional Artifacts	State at milestone
Business Case	Updated if architectural investigations uncover issues that change fundamental project assumptions.
Analysis Model	May be developed as a formal artifact; frequently not formally maintained, evolving into an early version of the Design Model instead.
Training Materials	User Manuals & other training materials. Preliminary draft, based on use cases. May be needed if the system has a strong user interface aspect.

The Role of Prototyping

The Rational Unified Process gives the architect and project manager the freedom to construct prototypes of several types (see Concepts: Prototypes) as a risk reduction strategy. Some of these prototypes may be purely exploratory, and are subsequently discarded. However, it is likely (certainly for larger or unprecedented systems) that the architecture will have been constructed as a series of evolutionary prototypes - covering different issues as elaboration proceeds - and by the end of elaboration, will have culminated in an integrated, stable architectural base. We do not mean to suggest here that the prototyping effort during elaboration should result in a set of architectural fragments, which need not be integrated.