This paper defines a methodical approach, named Solution Architecting Mechanism (SAM), to coping with the architecture complexity of enterprise information systems in IT solution designs. This comprehensive mechanism consists of eight interconnected modules: Solution Architecting Framework for eServices, Prescriptive Artineering Method, Solution Open Architecture Planning, Architecture Stack and Perspectives, Model-centric Architecting Process, Architecture Lifecycle and Readiness Maturity, Common Application Platform, and P20 Tao Model. Collectively, these modules form a holistic discipline guiding the process of development of architected solutions in an enterprise computing environment. Several unconventional concepts and thinking styles are proposed in this document. Part of this overarching mechanism has been extensively utilized in one form or another to develop various IT solutions across a broad range of industrial sectors. Reference solutions are presented to illustrate the exemplary implementations of some key elements in SAM. Best practices as well as lessons learned are discussed in the context.