C1. Consider Software as a Service before making the commitment to run an application at all

Prior to any consideration of systems architecture and design, during the process of requirements analysis, the availability and suitability of Software as a Service (SaaS) solutions should be considered.

The evaluation and selection of SaaS solutions depends on an interrelated set of considerations outside the scope of a technical system architecture discussion; e.g. precise specification of functional requirements by functional areas, accurate estimation of costs of alternative solutions, and ability of financial models to accommodate recurring costs of the SaaS solution.