De-couple Stages

Problem: How do you de-couple stages (architecture, design, coding) in a development process?

Context:

A design and implementation process for a well-understood domain.

Forces:

Stages should be independent to reduce coupling and promote independence between stages.

Independence hampers information flow.

Independence creates opportunities for parallelism.

Solution:

For known and mature domains, serialize the steps. Handoffs between steps should take place via well-defined interfaces. This makes it possible to automate one or more of the steps, or to create a pattern that lets inexpert staff carry out the step.

Resulting Context:

The new organization allows for specialization in carrying out parts of the process, rather than emphasizing specialization in solving the customer problem. This approach is "safe" only for well-understood domains, where the mapping from needs to implementation is straightforward. Domains that are well-understood are also good candidates for mechanization. For less mature domains, the process should b uild on the creativity of those involved at each stage of the process, and there should be more parallelism and interworking.

This pattern prepares for Hub-Spoke-and-Rim

Design Rationale:

See the forces.

Next: Hub-Spoke-and-Rim