Nonlinear Work: When Superposition Fails

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. [Brooks 1982] 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 issue 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!

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.

This article in its entirety was written by a human being. No machine intelligence was involved in any way.

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:

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.

Scope Creep and Confirmation Bias

As we've seen, some cognitive biases can contribute to the incidence of scope creep in projects and other efforts. Confirmation bias, which causes us to prefer evidence that bolsters our preconceptions, is one of these.

Avoid Having to Reframe Failure

Yet again, we missed our goal — we were late, we were over budget, or we lost to the competition. But how can we get something good out of it?

Anticipating Absence: Quarantine and Isolation

When the pandemic compels some knowledge workers to quarantine or isolate, we tend to treat them as if they were totally unavailable. But if they're willing and able to work, even part-time, they might be able to continue to contribute. To make this happen, work out conditions in advance.

Rational Scope Management

In project management, rational, responsible scope management helps us focus on the task at hand. But rational scope management lets us adapt our work to changes in external factors, and changes in our understanding of the problem.

See also Project Management and Project Management for more related articles.

Forthcoming issues of Point Lookout

Coming May 14: Working with the Overconfident

A cognitive bias known as the Overconfidence Effect causes us to overestimate the reliability of our judgments. Decisions we make based on those judgments are therefore suspect. But there are steps we can take to make our confidence levels more realistic, and thus make our decisions more reliable. Available here and by RSS on May 14.

And on May 21: Mismanaging Project Managers

Most organizations hold project managers accountable for project performance. But they don't grant those project managers control of needed resources. Nor do they hold project sponsors or other senior managers accountable for the consequences of their actions when they interfere with project work. Here's a catalog of behaviors worth looking at. Available here and by RSS on May 21.

Coaching services

I offer email and telephone coaching at both corporate and individual rates. Contact Rick for details at rbrenDJpmhgyaDTwBQXkhner@ChacmGoYuzfZpOvDQdRkoCanyon.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