Compound COGS.
The board sees three flags.
PHM shows one compound event.

The standard model runs three independent sensitivities and produces a combined COGS impact of +4.2%. It is not wrong — it is incomplete. PHM runs the same three signals simultaneously and produces +9.7%. The 2.3× compound factor is not an adjustment or a multiplier applied at the end. It emerges from the interaction: energy stress reduces scheduling flexibility at the exact moment logistics delays extend lead times at the exact moment steel costs arrive. Each mechanism makes the others worse. The highest single delta is P[4] — the steel lag arriving in June, not yet visible in any standard model.

The 2.3× compound factor is not an estimate. It is derived from the documented interaction coefficients across three simultaneous P[0], P[3], and P[4] activation events. PHM has mapped this configuration against three historical precedents: the 1973 oil shock, the 1980 stagflation cycle, and the 2022 European energy crisis. In all three cases, simultaneous activation produced compound COGS outcomes 1.8–2.6× worse than the sum of independent sensitivities. The 2022 precedent is the closest match at 91% signal configuration alignment. The preparation window exists because the compound factor is predictable — but only if you read the full signal environment before the steel lag arrives in June.

BMW and Stellantis are simultaneously operating under active procurement cost reduction mandates. This is not a negotiation position — it is a structural response to the same signal environment activating on their own P&L. The pass-through that would normally offset compound COGS is blocked at the exact moment the compound cost pressure is arriving. The supplier is caught between two sides of the same signal event: input costs rising, customer pass-through window closing. This is what the outside-in layer adds — the reading of the customer environment that the standard model, which stops at the company boundary, cannot produce.