
Congestion on a U.S. highway. One common example of the nonlinearity of systems is the traffic jam. At low densities, adding one more vehicle to the stream of traffic has no measurable effect on the speed of the other vehicles. But as density increases, traffic slows, until it reaches a state like the one shown. How can this be? This phenomenon occurs because of interactions between the vehicles. That is, the natural flow rate is a nonlinear function of vehicle density. Photo courtesy U.S. Department of Transportation.
More often than we'd like, our projects are late or over budget. Or we find that the problem we've tackled is much more difficult than we thought. We aren't stupid (though some might argue otherwise), and we aren't trying to gild lilies our build empires (though some might argue with that, too). Still, these things happen with such regularity that there must be an explanation.
Part of the answer might be that much of the work we do is of a nature that our minds have difficulty comprehending. One property that gives us trouble is nonlinearity.
For example, consider the issue raised by Fred Brooks in The Mythical Man-Month. If three people can complete a task in six months, many would suppose that nine people can complete it in two months. We now understand that this belief is unfounded, and that our expectations are rarely met.
To understand why, let's begin by defining linear work. Work is linear when the outcomes are directly traceable from, and scale with, inputs. When work is linear, we can successfully plan the outcomes before we begin, because we can predict the course of the effort. To make linear tasks go faster, we can divide them into parts that we execute in parallel, without risking complication.
For example, two identical, independent assembly lines can produce output at double the rate of one single line, assuming that their supply and delivery chains are also independent. A manufacturing process implemented as independent assembly lines is a linear process.
But In a system that doesn't
obey superposition, the whole
can be different from
the sum of its partsnonlinear work doesn't follow this pattern. Although most of the work we do in project-oriented organizations behaves linearly in response to small adjustments, the nonlinearities dominate when we scale those adjustments to a size where we expect to derive large benefits. One attribute of nonlinear work that explains this phenomenon is its failure to obey superposition.
In a system that doesn't obey superposition, the whole can be different from the sum of its parts. In such cases, as we apply more and more resources, the yield per unit of resource can decline. In the case of Brooks's mythical man-month, this can happen because of increased need for management and communication, and increased difficulty in scheduling.
But superposition can fail for a wide variety of reasons. For example, when we decompose a problem into parts, and try to work on the parts separately, one task team might require — solely for scheduling purposes — that another task team take an approach that is less effective than it would have taken if it were free to act independently. We can easily generate numerous examples like this that show failures of superposition that confound our expectations.
In three weeks, we'll continue this exploration of the reasons why nonlinear work is so difficult to manage. Next in this series Top
Next Issue
Are your projects always (or almost always) late and over budget? Are your project teams plagued by turnover, burnout, and high defect rates? Turn your culture around. Read 52 Tips for Leaders of Project-Oriented Organizations, filled with tips and techniques for organizational leaders. Order Now!
Your comments are welcome
Would you like to see your comments posted here? rbrenEQuetChPjwYBDxmgner@ChacxXTxBssoFmfDfMugoCanyon.comSend me your comments by email, or by Web form.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:
Nine Project Management Fallacies: IV
- Some of what we "know" about managing projects just isn't so. Understanding these last three
of the nine fallacies of project management helps reduce risk and enhances your ability to complete
projects successfully.
The Injured Teammate: II
- You're a team lead, and one of the team members is suddenly very ill or has been severely injured. How
do you handle it? Here are some suggestions for breaking the news to the team.
Beyond Our Control
- When bad things happen, despite our plans and our best efforts, we sometimes feel responsible. We failed.
We could have done more. But is that really true? Aren't some things beyond our control?
Scope Creep, Hot Hands, and the Illusion of Control
- Despite our awareness of scope creep's dangerous effects on projects and other efforts, we seem unable
to prevent it. Two cognitive biases — the "hot hand fallacy" and "the illusion
of control" — might provide explanations.
How to Get Out of Firefighting Mode: I
- When new problems pop up one after the other, we describe our response as "firefighting."
We move from fire to fire, putting out flames. How can we end the madness?
See also Project Management for more related articles.
Forthcoming issues of Point Lookout
Coming May 25: On Reporting Noncompliance
- Regulating compliance with process design in organizations requires monitoring process usage. Typically, process monitors depend on reports by process participants. In blame-oriented cultures, fear of retribution can limit what these reports contain. Available here and by RSS on May 25.
And on 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.
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.
- 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?
Decis
ion 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.
- 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.
Follow Rick





Recommend this issue to a friend
Send an email message to a friend
rbrenEQuetChPjwYBDxmgner@ChacxXTxBssoFmfDfMugoCanyon.comSend a message to Rick
A Tip A Day feed
Point Lookout weekly feed
