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. (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

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.