As people often think too positively about their own plans, these plans may fail due to unforeseen issues. There are also a number of cognitive biases related to planning: normalcy bias, optimism bias, and planning fallacy. But I can add even more, because almost every bias can influence people’s decision making. Fortunately people invented a number of methods to make better plans.
One of these methods consists of imagining what can go wrong before making any decision or acting on a plan.