I struggled to find a satisfactory definition of fit for purpose architecture.

Here is the best I could come up with. Please suggest any improvement you can offer, and add links to other definitions that you found helpful.

A solution/application/system/service architecture is fit for purpose when it is acceptably and reasonably:

– fit for its intended purpose: does what it’s supposed to do (meets the requirements of its users and sponsor)
– appropriate: is aligned to the existing strategy and as congruent as possible with the target architectures and roadmaps
– of a necessary standard: adequately addresses the concerns of those stakeholders with enterprise requirements
– economically viable: implementable within a reasonable time and at a reasonable cost

Enterprise Requirement is a requirement that exists beyond the boundaries of the program. These are sometimes referred to as standards, policies or constraints. Regulatory, Security, Strategic alignment, Business Continuity, Operability, Outsourcing, Policies, etc. are examples of enterprise requirements.