The Planning Fallacy and Self-Interest

Project plans usually include estimates of costs and schedules in addition to plans for work to be done, and the order of doing that work. Sometimes we fail to complete all the work we had in mind; sometimes we find we cannot do some work we wanted to do; sometimes we discover additional work we needed to do. But overall, the work actually done in a project does roughly approximate the work that was planned. Not so for cost and schedule. Cost and schedule can differ from projections by double, triple, and more, even when we make allowances for differences between work planned and work actually done.

In a 1977 report, Daniel Kahneman and Amos Tversky identify a particular cognitive bias, the planning fallacy, which afflicts planners. [Kahneman 1977] [Kahneman 1979] They discuss two types of information used by planners. Singular information is specific to the project at hand; distributional information is drawn from similar past efforts. The planning fallacy is the tendency of planners to pay too little attention to distributional information and too much attention to singular information, even when the singular information is scanty or questionable. Planners tend to underestimate cost and schedule by failing to harvest lessons from the distributional information, which is inherently more diverse and reliable than singular information.

But even when planners attend to distributional information, two forms of self-serving considerations can lead planners to make estimates that cannot be met. Here's how.

Self-serving bias

Choosing local experts is a common pattern for designating people to make estimates of cost and schedule. Usually the experts designated tend to be people who've done similar work in the past, and sometimes they must assess their own past work. When estimators must evaluate their own work, they have a conflict of interest that can compromise objectivity as a result of a cognitive bias known as self-serving bias. [Campbell 1999] Self-serving bias causes us to perceive ourselves more positively than objective judgment warrants. We tend to attribute successes to our own talents and decisions, and attribute failures to external factors.

When the The work actually done in a
project does roughly approximate
the work that was planned.
Not so for cost and schedule.estimators designated for a project were themselves involved in the past efforts they're evaluating for estimation purposes — what Kahneman and Tversky call distributional information — self-serving bias tends to lead them to biased conclusions, which they then use to make projections for the project whose cost and schedule they're estimating.

Organizational politics

From the perspective of objective estimation based on balanced assessment of distributional and singular information, organizational politics can make a bad situation even worse. Estimators who are evaluating past efforts in which they played roles can use their evaluations as tools of what psychologists call impression management — to make themselves look good. They can thus enhance their own prospects for advancement. [Drory 2006] In this way, politics can limit the willingness of estimators to faithfully represent sources of successes and failures in past efforts. In effect, to gain political advantage, estimators tend to attribute too much of the reason for past successes to their own actions, and too much of the reason for past failures to external factors or to the actions of others, especially political rivals.

The distortions that result from the planning fallacy, from self-serving bias, and from organizational politics can reduce the chances that estimators will produce reliable results. When that happens, cost overruns and schedule delays become more likely.  Top    Next Issue

Is every other day a tense, anxious, angry misery as you watch people around you, who couldn't even think their way through a game of Jacks, win at workplace politics and steal the credit and glory for just about everyone's best work including yours? Read 303 Secrets of Workplace Politics, filled with tips and techniques for succeeding in workplace politics. More info

Footnotes

Your comments are welcome

About Point Lookout

Thank you for reading this article. I hope you enjoyed it and found it useful, and that you'll consider recommending it to a friend.

Point Lookout is a free weekly email newsletter. Browse the archive of past issues. Subscribe for free.

Support Point Lookout by joining the Friends of Point Lookout, as an individual or as an organization.

Do you face a complex interpersonal situation? Send it in, anonymously if you like, and I'll give you my two cents.

Related articles

More articles on Project Management:

Status Risk and Risk Status

One often-neglected project risk is the risk of inaccurately reported status. That shouldn't be surprising, because we often fail to report the status of the project's risks, as well. What can we do to better manage status risk and risk status?

Nine Project Management Fallacies: II

Some of what we "know" about managing projects just isn't so. Identifying the fallacies of project management reduces risk and enhances your ability to complete projects successfully.

Nonlinear Work: When Superposition Fails

Much of the work we do is confounding, because we consistently underestimate the effort involved, the resources required, and the time required to get it done. The failure of superposition can be one reason why we get it wrong.

How We Waste Time: II

We're all pretty good at wasting time. We're also fairly certain we know when we're doing it. But we're much better at it than we know. Here's Part II of a little catalog of time wasters, emphasizing those that are outside — or mostly outside — our awareness.

Defect Streams and Their Sources

Regarding defects as elements of a stream provides a perspective that aids in identifying causes other than negligence. Examples of root causes are unfunded mandates, misallocation of the cost of procedure competence, and frequent changes in procedures.

See also Project Management and Cognitive Biases at Work for more related articles.

Forthcoming issues of Point Lookout

Coming June 1: Mental Accounting and Technical Debt

In many organizations, technical debt has resisted efforts to control it. We've made important technical advances, but full control might require applying some results of the behavioral economics community, including a concept they call mental accounting. Available here and by RSS on June 1.

And on June 8: Flexible Queue Management

In meetings of 5-30 participants, managing the queue of contributors can be challenging. A strict first-in-first-out order can cause confusion and waste of time if important contributions are delayed. Some meetings need more flexible queue management. Available here and by RSS on June 8.

Coaching services

I offer email and telephone coaching at both corporate and individual rates. Contact Rick for details at rbrenEQuetChPjwYBDxmgner@ChacxXTxBssoFmfDfMugoCanyon.com or (650) 787-6475, or toll-free in the continental US at (866) 378-5470.

Get the ebook!

Past issues of Point Lookout are available in six ebooks:

• Get 2001-2 in Geese Don't Land on Twigs (PDF, )
• Get 2003-4 in Why Dogs Wag (PDF, )
• Get 2005-6 in Loopy Things We Do (PDF, )
• Get 2007-8 in Things We Believe That Maybe Aren't So True (PDF, )
• Get 2009-10 in The Questions Not Asked (PDF, )
• Get all of the first twelve years (2001-2012) in The Collected Issues of Point Lookout (PDF, )

Are you a writer, editor or publisher on deadline? Are you looking for an article that will get people talking and get compliments flying your way? You can have 500-1000 words in your inbox in one hour. License any article from this Web site. More info

Public seminars

The Power Affect: How We Express Our Personal Power

Many people who possess real organizational power have a characteristic demeanor. It's the way they project their presence. I call this the power affect. Some people — call them power pretenders — adopt the power affect well before they attain significant organizational power. Unfortunately for their colleagues, and for their organizations, power pretenders can attain organizational power out of proportion to their merit or abilities. Understanding the power affect is therefore important for anyone who aims to attain power, or anyone who works with power pretenders. Read more about this program.

• A recording of a program presented June 29, 2017, Monthly Webinar, sponsored by Technobility Webinar Series. PMI members can earn 1.0 Category 'A' PDU by viewing this program. View this program now.
   
• A recording of a program presented June 29, 2017, Monthly Webinar, sponsored by Technobility Webinar Series. PMI members can earn 1.0 Category 'A' PDU by viewing this program. View this program now.
   

Bullet Points: Mastery or Madness?

Decision makers in modern organizations commonly demand briefings in the form of bullet points or a series of series of bullet points. But this form of presentation has limited value for complex decisions. We need something more. We actually need to think. Briefers who combine the bullet-point format with a variety of persuasion techniques can mislead decision makers, guiding them into making poor decisions. Read more about this program.

• A recording of a program presented June 24, 2020, Monthly Webinar, sponsored by Technobility Webinar Series. PMI members can earn 1.0 Category 'A' PDU by viewing this program. View this program now.
   
• A recording of a program presented June 24, 2020, Monthly Webinar, sponsored by Technobility Webinar Series. PMI members can earn 1.0 Category 'A' PDU by viewing this program. View this program now.