The Planning Fallacy: Why You Miss Your Deadlines, And What to do About it

Thomas Oppong
Oct 22, 2018 · 6 min read
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How often do you find yourself racing at the last minute to finish a task?

If you’ve ever missed a deadline the planning fallacy may well be the culprit.

Most people are more conscious about time and how they use it. They have a better awareness of how much of it they will spend on impending tasks.

Others are very prone to be optimistic when ‘budgeting’ it. They display an optimism bias and underestimate the time needed for every task for the day.

This is a common pitfall when managing time, called ‘the planning fallacy’.

We consistently underestimate how long it will take to write a post, an ebook, record podcast, complete a side project, or hold a meeting.

The planning fallacy was first proposed by Daniel Kahneman and Amos Tversky in 1979.

This phenomenon can occur regardless of your knowledge that past tasks of a similar nature have taken longer to complete than generally planned.

“The more steps you have in whatever project or task you’re working on, the greater the chance that in one of those steps you’re going to hit a snag and it’s going to turn out to be atypical,” writes Julia Galef of Big Think.

Planning fallacy is one of the most common and consistently demonstrated cognitive biases.

For example, a house can only be built on time if there are no delivery delays, no employee absences, no hazardous weather conditions, etc.

Even if each hurdle is unlikely, there is a high probability that at least one will occur.

In every project, people rarely consider the what ifs, which is why they underestimate their task completion times.

The good news is that being aware of how cognitive biases affect you can help you be on the lookout for them, and change your behaviour to compensate.

Resist the tyranny of the urgent

Urgency wrecks productivity. Your ability to distinguish urgent and important tasks has a lot to do with your success.

Dwight D. Eisenhower once said, “What is important is seldom urgent and what is urgent is seldom important.”

Urgent tasks require your immediate attention: phone calls, meetings, tasks with tight deadlines, and other issues that require you to take action quickly.

Important tasks help advance long-term goals and complete serious projects. They are tasks that actually push the needle.

But unfortunately, we tend to put important tasks aside and deal with the urgent tasks that provide a rapid sense of accomplishment but doesn’t help advance long-term goals.

Kat Boogaard of Trello explains, “Our brains have the not-so-helpful tendency to conflate real, productive work with those other small, menial, and mindless tasks. By totally pushing those out of your mind (and off your to-do list) for now, you won’t be tempted to color code your inbox when you should actually be completing that presentation that’s due in two hours.”

Learn to limit the amount of time you’re wasting on non-urgent/non-important tasks.

The fundamental approach to solving this vicious circle of work is to understand the difference between urgent tasks and important tasks.

Break big tasks into smaller pieces

When you are making predictions, pay attention to the steps you need to take, and not just the outcome.

People who procrastinate often feel overwhelmed and the task seems insurmountable.

By breaking a bigger project into smaller tasks, the work is more manageable and less intimidating.

Think of each component that is involved in the process, and allocate time for it to be completed.

Examine the parts of any task, and figure out step-by-step what you need to do to get it done.

Create a timeline for completing your tasks. Having a deadline will make you more focused for each task.

Give yourself 30 minutes to complete something or an hour. If the task is too large to complete in an hour, break it into smaller tasks, and time box those smaller tasks.

To help you stick with your new work hours, set appointments for 30 minutes after you’re supposed to get off work. So if you tell yourself you’re absolutely going to leave work at 5 p.m. (or even better, at 3 p.m.), set an appointment for 5:30 p.m. and stick to it.

Set a hard deadline.

Set a specific goal for the end of that length of time, and set it in stone.

If you set a tighter deadline for each of your tasks today, you’ll be inspired to find the most productive way to meet those deadlines and get your work done.

Make a list of the tasks you need to accomplish by close of day today. Then, think about how much time it will take to accomplish each of those tasks.

Once you begin your work, you’ll find you’re in a race against the clock.

That’s exactly what you want because it will inspire you to get it done.

When you’re done, take a look back and see how you’ve fared. Measure your progress and improve accordingly.

Did you inflate the time required for some tasks?

There may be some tasks that you simply can’t cut hours on or some that you can cut even more time from.

Adjust your schedule to work better, faster and smarter.

Use the Pomodoro technique

The Pomodoro technique teaches us to work with time, instead of struggling against it. It can help you power through distractions and get things done in short bursts.

The Pomodoro Technique, strictly about time-management was developed by Italian entrepreneur Francesco Cirillo. He created this simple study habit (when he was still a college student in the late 1980s) to maximize his productivity and reduce a feeling of burnout.

It focuses on working in short, intensely focused bursts (20/30/40 minutes), and then giving yourself a brief break to recover and start over.

The technique requires a timer, and it allows you to break down your large complex task into manageable intervals.

Once you start a task, you aim to finish it before attending to urgent but unimportant tasks.

Beware of “time bullies”

Say no more often.

”Saying “No” means you have time to focus on your own creation, tasks and projects, rather than responding and reacting to requests.

In the words of Paulo Coelho: “When you say YES to others, make sure you are not saying NO to yourself.”

Don’t get suckered into tasks you don’t have time for.

Saying No is hard, but it means you say Yes to focus and sanity. Use your power of choice to say “Yes” or “No” when you mean it.

Key takeaway

If you are able to recognize and address this issue before it gets out of hand, you will be less likely to allow it to impact your success.

Human judgment sucks.

Don’t rely on your personal, subjective judgment of how long something is likely to take or how involved it will be because that’s likely to suck.

Measure and compare.

How well did past projects performed in terms of their PLAN versus the ACTUAL time it took to complete?

  • What went well?
  • What didn’t go so well?
  • What can you do differently next time?

Rely on evidence.

Track your progress and base your decisions on past evidence.

Dig deeper

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Thomas Oppong

Written by

Founder @AllTopStartups | Contributor at Business Insider. I share tools for wealth, health and happiness at

A network of business & tech podcasts designed to accelerate learning. Selected as “Best of 2018” by Apple.

Thomas Oppong

Written by

Founder @AllTopStartups | Contributor at Business Insider. I share tools for wealth, health and happiness at

A network of business & tech podcasts designed to accelerate learning. Selected as “Best of 2018” by Apple.

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