Skip to main content

Logic Decay

The failure mode in which agentic logic produces increasingly incorrect outputs not because the code is defective, but because the data environment it was calibrated for has shifted — a miscalibration that compounds silently until it produces a visible error.

Extended Definition​

Logic Decay is the most insidious of the three primary autonomous system failure modes because it is invisible at the point of origin. A software bug is present from deployment and detectable by testing. Logic Decay is introduced by environmental change after deployment: customer behaviour shifts, market pricing moves, an API updates its schema, regulatory parameters change. The logic gate that produced correct outputs in Q1 continues executing in Q3 — against a data environment it was never calibrated for. Each individual output is plausible. The accumulated drift is not. The error compounds until it produces a failure that is impossible to miss, at which point it has typically been running for weeks.

  • Continuous Regression Loop — The Continuous Regression Loop is the architectural response to Logic Decay: it detects environmental miscalibration through Ghost Trials before the compounding error reaches the revenue loop.
  • Ghost Trial — The Ghost Trial is the detection mechanism for Logic Decay: simulated production data through live logic reveals when the calibration no longer matches the current data environment.
  • Deterministic Failure — Logic Decay is converted into a Deterministic Failure event when the Continuous Regression Loop detects it: the deviation is flagged, logged, and escalated before it reaches live transactions.
  • Context Leakage — Both Logic Decay and Context Leakage produce silent, compounding errors; the distinction is that Logic Decay originates in environmental data drift while Context Leakage originates in task-level intent drift within a single workflow.
  • Architectural Certainty — Protecting against Logic Decay through Continuous Regression Loops is a design requirement for Architectural Certainty: a system without environmental drift detection cannot maintain reliable autonomous operation over time.
  • Handoff Friction — Both Handoff Friction and Logic Decay produce outputs that appear valid but are incorrect; Handoff Friction occurs at integration boundaries while Logic Decay occurs in the core business logic calibration.

Articles​

References​

  • Lexicon — canonical definition
  • Wiki — extended entry

Metadata​

First used: 2026-03-23
Pillar: What We've Learned

Part of the Arco Lexicon Ecosystem — maintained by Arco Venture Studio