System Dynamics - Cost Growth (AI vs No-AI)

This toy model uses Engineering Quality as a state Q(t) (automation, CI speed, tests, guardrails, refactoring discipline). Quality acts as an inverse multiplier on operations and maintenance cost. AI primarily amplifies the control loop (change capability), accelerating software volume growth (V(t)).

This chart compares total cost for three regimes (Average, Quality Investment, Sloppiness), each shown with and without AI. AI-on uses aiAmplification = 2.0; AI-off uses aiAmplification = 1.0.

Total cost proxy: C = C_D + C_O + C_M with C_O ∝ λ·(1/Q)^b, C_M ∝ B·(1/Q)^g, and λ ∝ V·r·(1/Q)^a·g(φ).