Use Traffic Delay to Measure Congestion

 “Traffic Delays to Triple” read a headline about highway congestion in my morning paper.  It turns out that planners use traffic delay to measure the cost of highway congestion.

This would be a good way to measure project congestion on your new product highway.

We’ve all experienced traffic jams (if you’re from Southern California you’re an expert).  When traffic is congested, it takes too long to get home, and your arrival time is unpredictable.  The figure below, based on Don Reinertsen’s The Principles of Product Development Flow (pages 170-172), shows how high traffic density reduces throughput.

Traffic density reduces throughput

With highway traffic, too many cars start to interfere with each other, they begin to slow down, and vehicle throughput declines.

The same thing happens in product development.  Companies’ most common headaches are that projects take too long and schedules are unreliable. Yet these same companies start too many projects, congesting project traffic, delaying projects and making schedules unreliable.

But how can you push back on project congestion without coming off as a whiner?  One way would be to build a case against congestion by assessing traffic delay as an objective measure of the cost of congestion.

Put a cross functional task force together for a retrospective on recent projects.  Estimate the total delays in weeks, weighted by the lifetime profit potential of each project to get a delay measurement in $M-Weeks.  (It would be better to use a financial cost of delay model to translate delay directly into economic loss.  But most companies don’t use these models, as I’ve lamented previously.)

Apply your best judgment to look only at delays that are caused by congestion:

  • Time spent waiting in queues at resource bottlenecks
  • Time waiting for an engineer from another project that didn’t finish on time.
  • Delay caused when an engineer was diverted to fight a fire with another project.
  • Delay caused by multitasking.  When sharing resources means alternately putting projects on hold while another one gets resources.
  • Cases where an expert needed to solve an unexpected problem was already committed elsewhere.
  • Opportunity delay, when a project might have been accelerated with more staffing. (For this one, estimate what the project schedule might have been with a reasonable staffing increase.)

Be sure to honestly estimate congestion delays without including delays from other sources, such as underestimated tasks, or “normal” process overhead.

This assessment will tell you how much project congestion is costing you.  If the figure is large, you have a concrete basis for better new project onramp control.  This will ease congestion and make projects faster and more predictable.  And maybe you’ll be able to get home on time.

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