Risk and Cost Driven Architecture (RCDA)

Risk and Cost Driven Architecture (RCDA), developed by Eltjo Poort at CGI, is a pragmatic framework for enterprise and software architecture that frames every significant decision as a trade-off between risk reduction and cost. Architecture stops being a documentation exercise and becomes a continuous negotiation: which decisions warrant investment now because deferring them is expensive, and which can wait because the cost of being wrong is bounded.

The framework matters because most architectural discussions confuse activity with progress. Diagrams accumulate, ADRs get written, technology choices are debated — and meanwhile the system grows in directions nobody owns. RCDA asks a sharper question: what is the risk we are buying down, what does it cost, and is that ratio defensible against the alternatives?

The articles in this collection apply RCDA thinking to concrete situations. Technical debt is treated as a financial instrument with interest payments rather than a vague quality complaint — small shortcuts compound into dominant cost drivers three years in, and the metaphor of “forgotten pennies and lost dollars” captures the mechanism precisely. Visibility comes first: analyzers, code metrics, and Azure DevOps dashboards illuminate debt that would otherwise stay hidden in the codebase until it forces a rewrite.

A second cluster addresses retiring legacy .NET projects, where the question is no longer “how do we keep this running” but “what is the cheapest path to forward motion”. Modular extraction, strangler patterns, and risk-weighted prioritization replace the all-or-nothing rewrite that usually fails. Cost-driven decisions name the constraint explicitly rather than hiding it behind technical preference.

The voice across these articles avoids architecture astronautics. Decisions are documented, justified by risk and cost, and revisited when circumstances change. That discipline is what separates RCDA from the framework-of-the-month cycle that surrounds it.