Mental simulation shows up in at least three places in the RPD model: diagnosing to form situation awareness, generating expectancies to help verify situation awareness, and evaluating a course of action.
The middle one is least intuitive. "If my understanding is correct then we should see X next." This helps validate understanding and is common in time critical situations. It may not be communicated commonly in those situations though, which is why the first C in STICC model is a great reminder to communicate this information.
