Clarifying and distilling the top-level functional and nonfunctional requirements of the software is a key prerequisite for success. If you don't know what to build, your chances of building something that customers want are pretty slim. Product managers often get caught up on features, but rarely ask what non-functional requirements (or system qualities) the customers need. Sometimes, stakeholders will tell us that the system must be fast, but that's far too subjective. Non-functional requirements need to be specific, measurable, achievable, and testable if we are going to satisfy them. The architect needs to work with all stakeholders and ensure that functional and nonfunctional requirements are well crystallized and consumable for development.

In today's agile world, requirement analysis is an almost ongoing activity. But the architect helps the team navigate the requirements and take decisions on what to do (which may not always be so obvious).