Commander's Intent is a military planning mental model that communicates the desired end-state of a mission so clearly that subordinates can make correct decisions without further orders — even when the original plan has broken down. Developed formally in the US Army in the 1980s, it solves the pervasive organizational problem of compliance versus initiative: teams that execute orders literally but miss the point when conditions change.
Entropy is a thermodynamic concept — the tendency of closed systems to drift toward disorder — that applies broadly to organizations, software, relationships, and physical spaces. Without continuous energy input to maintain structure, systems naturally degrade. Understanding entropy explains why code quality deteriorates, why organizational cultures drift, why relationships require maintenance, and why "letting things run themselves" rarely works.
Getting Things Done (GTD) is a personal productivity system and mental model designed to offload the burden of remembering tasks from the brain to a trusted external system. Developed by David Allen in 2001, it focuses on the principle that "your mind is for having ideas, not holding them." By systematically Capturing, Clarifying, Organizing, Reflecting, and Engaging with tasks, GTD neutralizes the Zeigarnik Effect and reduces Cognitive Load. Understanding GTD allows individuals to achieve a state of "Mind Like Water," maintaining high-performance focus even in environments of extreme information overload and complexity.
Scale Effects describes how systems behave qualitatively differently at different magnitudes. What works at 10 people often fails at 100, and what works at 100 often fails at 1,000 — not because the people or strategy are worse, but because scale changes the fundamental dynamics. Understanding scale effects is essential for organizational design, startup scaling, infrastructure planning, and biological systems.