Architecture process

With proper design, the features come cheaply. This approach is arduous, but continues to succeed.

Dennis Ritchie

Architecture work is a process — It takes time, it takes effort, and it takes experience.

Find and document the major and critical use cases and requirements. Establish an outline candidate architecture which contains the most crucial subsystems. The most important risks are identified and prioritised. The project is roughly estimated.
The requirements and use cases are specified in detail, and the candidate architecture is elaborated into an architecture baseline which will guide the construction and transition phases. The remaining project is planned in detail.
The system is designed and build, guided by the architecture baseline. Even though the architecture is stable, the developers may suggest adjustments to the architecture as they find better ways to structure parts of the system. The product is developed into a running release of the complete system, covering all use cases and requirements. The product may still have defects, but some customers will be able to use the system.
The product is brought to a beta release, and remaining defects are found and fixed. The transition phase is complete when the product is fully and unconditionally released.