How to avoid taking three lefts when you can go right: Making the architectural perspective count

摘要

Although current trends in software development methodologies allow for changes to requirements at various phases of development, modifying the existing system design to reflect these changes is often architecturally challenging. In many real world instances, seemingly simple updates to user or functional requirements often have a significant impact on several dimensions of the overall system architecture. The effects of this impact make the realization of the change architecturally infeasible within the constraints imposed by other requirements, the existing architecture, the technical environment, and the available resources. Here, we describe two instances of this issue that were encountered in an industry project to highlight why it is critical to have a visible, distinct, and continuously updated mapping between requirements and constraints. We share some insights from our experiences, and outline possible approaches that would help establish a dialogue between the product manager and the system architect in a project, before modifications to requirements are accepted.