The Demand–Capacity Principle: A General Systems Framework for Problem Difficulty, Overload, and Resolution

Why do otherwise different systems—people, organizations, computers, electrical grids, healthcare services, machines, and ecosystems—develop recognizably similar states of backlog, strain, degradation, and failure? This conceptual paper proposes the demand–capacity principle as a domain-neutral account of their shared structure. For a bounded system, specified function, time horizon, and acceptable performance standard, difficulty arises when the demands that must be handled fall outside the system’s feasible response capacity. The familiar expression Demand > Capacity is treated as shorthand for a multidimensional, time-dependent mismatch. The paper distinguishes precipitating events from the structural conditions that make them difficult to handle. It relates the framework to queueing theory, cybernetics, person–environment fit, job demands–resources theory, conservation of resources, stress physiology, resilience engineering, and operational overload protection. It develops seven propositions, measurement requirements, boundary conditions, and a research agenda. It also proposes demand–capacity management as an umbrella term for reducing or reshaping demand, increasing or restoring capacity, changing timing and allocation, importing external capacity, and preserving feedback and reserve. Load shedding is defined as an acute special case rather than the complete solution. This is version 1.0 of a conceptual preprint. It has not been peer reviewed. It substantially develops the argument first published in the author’s Substack essay, “The Root Structure of Every Problem.”