The like-for-like swap is the failure mode
The MOC step skipped under schedule pressure isn't a footnote to the incident, it is the incident.
Every plant has the sentence. “It’s a like-for-like swap, we don’t need to run it through MOC.” Sometimes that’s true; a replacement in kind, by definition, doesn’t trigger Management of Change under 29 CFR 1910.119(l) (US, PSM-covered facilities). The problem isn’t the exception. It’s that “like-for-like” is a judgment call made at the exact moment the schedule is screaming, by the person who most wants it to be true.
The exception is where the work is
When you read US CSB investigation reports, a recurring pattern isn’t the absence of an MOC program, most sites had one. It’s a change classified as not-a-change that walked around the review that would have caught it. A slightly different alloy. A gasket rated for the wrong service. A “temporary” bypass that outlived the shift. Each looked like a swap; none was. Process-safety practice treats the determination of whether something is replacement-in-kind as itself safety-critical, deserving rigor rather than reflex. If the new component differs in metallurgy, rating, materials, or upset behaviour, it is not in kind, no matter how identical it looks on the shelf.
The tell is time. Nobody skips MOC when there’s slack. The shortcut appears precisely when the cost of stopping feels highest, which is also when the odds of a bad call are highest.
Before you buy
Pull your last 12 months of "replacement in kind" determinations. For each: who decided it was in kind, and could that decision be overruled by someone whose bonus doesn't depend on the schedule? If the classifier and the beneficiary of skipping MOC are the same person, you don't have a control, you have a rubber stamp.
Compliance says your MOC program exists and has signatures. The question is what happens at the fork when someone says “it’s just a swap” and the clock is running.