phasestages

Phasestages is a conceptual framework for analyzing and organizing processes that unfold through a sequence of phases, each containing several stages. The concept emphasizes two levels: phases represent major periods characterized by distinct objectives and deliverables, while stages are finer-grained steps within a phase that specify concrete activities and milestones. Transitions between phases are often governed by gates or decision points, ensuring progress and resource allocation decisions.

Phasestages is used in fields such as project management, product development, systems engineering, and research programs to describe how work progresses from initial idea to completion. The model helps align governance with workflow by pairing high-level phase objectives with stage-level criteria for advancing.

Common configurations include four or more phases such as initiation, feasibility, design, testing, and deployment, with multiple stages within each phase (feasibility study, risk assessment, concept validation, prototype testing, verification). Gates at phase boundaries determine go/no-go decisions.

Examples: In software development, phase 1 is Discovery with stages like market research and requirements elicitation; phase 2 is Planning with architectural design and risk analysis; phase 3 is Execution with implementation and integration testing; phase 4 is Release with user acceptance and deployment.

Advantages include clearer accountability, improved resource planning, and structured risk management through formal decision points. Limitations include potential rigidity and overhead, which can hinder rapid iteration, especially in agile environments, unless adapted to incorporate flexibility and fast feedback loops.

See also: stage-gate model, waterfall model, product lifecycle, systems engineering.