Run a mental simulation before committing to a course of action

Before acting on a recognized situation, mentally run through how your intended response plays out.

Why it works

In the RPD model, experts do not compare options — they evaluate one option by mentally simulating its execution. This simulation checks for show-stopper failure modes without the cognitive cost of generating and comparing multiple alternatives. If the simulation reveals a flaw, the plan is modified or discarded; if it holds up, action follows. The bottleneck is the quality of the simulation, not the number of options evaluated.

How to do it

1. When you have a course of action in mind, pause for sixty seconds and mentally walk through what happens if you execute it.
2. Specifically ask: "At what point does this fail, and what does failure look like?"
3. If you identify a failure point, ask whether the plan can be modified to avoid it before discarding it entirely.
4. If the simulation reveals no show-stoppers, act — do not manufacture additional options to compare.

Evidence

Klein’s RPD model, derived from observation of experienced decision-makers, identifies mental simulation as the primary evaluation mechanism in fast expert decision-making. Independent laboratory work on mental simulation supports its role in problem-solving and planning. Mitchell, Russo, and Pennington found that adopting a prospective-hindsight (“back to the future”) stance — imagining an outcome as already having happened — improves the specificity with which people simulate how events unfold. (observational)

Mental simulation quality depends on the accuracy of the underlying mental model of the domain. Overconfidence in simulation is a known failure mode, particularly in novel situations where the model is poorly calibrated.

Sources

• Klein (1998), Sources of Power: How People Make Decisions
• Mitchell, D. J., Russo, J. E., & Pennington, N. (1989). Back to the future: Temporal perspective in the explanation of events. Journal of Behavioral Decision Making, 2(1), 25–38.

Common mistake

Running the simulation only for the parts of the plan you are confident about and skipping the step where it transitions to something unfamiliar — the failure point is nearly always at a boundary.