Friction & Viscosity

Friction resists motion; viscosity is resistance to flow. In physics, friction opposes relative motion between surfaces; viscosity is the internal resistance of a fluid to deformation. Both make change harder and costlier. The same idea applies to organisations, markets, and behaviour: things that should move often don't, or move slowly, because something is resisting. The model helps you find and reduce the resistance — or, when you want stability, add it deliberately.

Friction shows up as switching costs, approval layers, and habit. Customers don't switch because the effort of moving is high. Projects stall because every step meets resistance. Viscosity shows up as slow flow: information that doesn't spread, decisions that don't propagate, or change that oozes instead of runs. High-viscosity organisations need more force (pressure, leadership, crisis) to achieve the same flow. The strategic question is whether you want to reduce friction and viscosity (faster change, easier switching) or increase them (stickier customers, more stable processes). Usually you want less internal friction and more friction for competitors trying to take your customers.

Startups often win by reducing friction in a high-friction industry — one-click ordering, instant approval, no paperwork. Incumbents sometimes rely on friction as a moat: complexity and switching costs keep customers in place. The model is neutral: friction can be friend or foe depending on where it sits. Map where resistance is, who benefits from it, and whether you should be lowering or raising it.