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Planning fallacy: why it always takes longer than you think to get things done


Human beings are generally "pretty lousy" at estimating the time they will need to complete a task, says Heidi Grant Halvorson on Fast Company – and obviously that has implications for managers everywhere.

Grant Halvorson explains: "Psychologists refer to this as the planning fallacy, and it's an all too common problem – one with the very real potential to screw up our plans and keep us from reaching our goals."


Studies into planning fallacy point to several different biases we have when we estimate how long it will take to do something:

• We routinely fail to consider our own past experiences while planning.

• We ignore the possibility that things won't go as planned and our future planning relies too heavily on best-case scenarios.

• We don't give enough consideration to all the steps that make up the task, or think about how long each part will take.

What's more, certain people are more prone to planning fallacy than others, and studies suggest that people in positions of power are especially vulnerable because "feeling powerful tends to focus us on getting what we want, ignoring the potential obstacles that stand in our way".

Grant Halvorson recommends three steps for managers making a plan and estimating how long it will take:

1) Consider how long it has taken in the past.
2) Think about how it might not go to plan.
3) Map out all steps needed to get it done.

The author says: "This is particularly important when you are in a position of power, so make sure that there are safeguards or reminders in place to help you to consider all the information you should. Otherwise, you may fall victim to the everything-takes-15-minutes kind of optimism that can lead to disaster."

Source Article: How Long Will This Take? Three Steps To Being A Better Judge Of Time
Author(s): Heidi Grant Halvorson
Publisher: Fast Company