Software Architect's Handbook

Constraints

Constraints are some type of restriction on the solution and may be technical or non-technical in nature. Some constraints on a project might be captured and classified as a functional or non-functional requirement, or they might be explicitly categorized as a constraint. Either way, the important thing is that they are decisions that have already been made and must be honored. Typically, a constraint cannot be changed, and the software architect does not have any control over it. However, if you have reasons why you believe a constraint should be changed or removed, there may be situations in which you could provide your input.

Constraints can pertain to a number of aspects of a software project. The following are some examples ...