Model Churn Exposure

Model Churn Exposure is the share of a client deliverable that breaks when the underlying model version, price tier or rate limit changes. Foundation model platforms ship new versions and routing changes on their own schedule, so any agency workflow pinned to a specific model inherits that vendor's release cadence as a delivery risk. The framework asks three questions per client engagement: how many prompts or pipelines name a model explicitly, how much of the output quality depends on that specific version, and who absorbs the cost of re-testing when it shifts. Mixture-of-experts routing choices already move output quality and inference cost inside a single model family, which means even a silent backend change can alter results. Agencies that map churn exposure before signing a retainer can price re-validation work into the scope instead of eating it, and can keep a second provider warm for the two or three workflows where a swap is cheap.