Hockey sticks are essential equipment for hockey players; whether amateur or professional, you can’t play without them. But unless we’re making them, we should never see hockey sticks in our business. The hockey stick I’m talking about here is the familiar pattern of a sharp increase in output at the end of the month or quarter.
This pattern is known as the hockey stick because it shows even process output
until the end of the month or quarter. Then it spikes up sharply, like the
business end of a hockey stick. The bad news is that no matter how many computer
systems and scheduling controls are put in place, the hockey stick production
curve is alive and well. Some of the largest companies on the planet still
follow this horribly wasteful practice.
The good news is that it is relatively easy to rectify, once we understand how
When managers are behind on the production
commitment near the end of the month or quarter, they do everything possible to
accelerate output. They might reallocate resources and capacity toward the back
end of the production process to get half-finished WIP to finished inventory.
They schedule overtime. They postpone scheduled training or improvement events.
They delay some capacity-draining changeovers or preventive maintenance. In
general, they go through many different mental and physical gyrations to
squeeze a little more out of the system for the last part of the month or
All of this and more is done in a desperate attempt to meet the
production commitment. But the single-minded pursuit of that goal creates huge
amounts of waste, both direct and indirect. The direct waste comes from
unnecessary overtime and unnecessary consumption of resources. The indirect
waste is insidious; it comes from a process that is not running at a constant
If you do this, everything that you did at the end of the period will come back
to bite you in the beginning of the next period. Postponed maintenance,
changeovers and training events will have to be batched, cutting into
production. The back-end WIP that was accelerated through the process is no
longer there, so you have to refill the process from the beginning. This in turn leads to a temporary drop in
output. In the end, you’ll achieve the same output over both periods, but
you’ll consume considerably more resources doing so than you would have by
sustaining a level output.
The real shame is that you’ll only get the “benefit” once from using the hockey
stick to “cheat.” After that, it’s only about avoiding the pain of reversing
the behavior. It only helps you once if you pull production ahead in month one,
because you stole from month two to get the output for month one. As a result,
you have to continue the hockey stick behavior just to stay even for month two,
and every month thereafter as long as the addiction
All it takes is one period of stopping the behavior to reverse this addiction.
It will hurt the month you stop the behavior because you will still have the
gap in the front part of the month and not be able to make it up in the back
end. But you will have broken the cycle and can return to a less wasteful
practice. The hockey stick behavior is such a serious manipulation of the
numbers that manufacturers should have to report it in the footnotes of their
The 2009 economic crisis is causing many
manufacturers to reduce output. If you’re trapped in hockey stick behavior,
this is a great time to break the cycle and put countermeasures in place to ban
the hockey stick from returning.
Jamie Flinchbaugh is a founder and
partner of the Lean Learning Center in Novi, MI, and the co-author of
The Hitchhiker’s Guide to
Lean: Lessons from the Road. He shares his successful and
varied experiences of lean transformation as a practitioner and leader through
companies such as Chrysler and DTE Energy. He also has a wide range of
practical experience in industrial operations, including production,
maintenance, material control, product development and manufacturing
engineering. Jamie is a graduate fellow of the Leaders for Manufacturing
Program at the Massachusetts Institute of Technology, where his research thesis
was on implementing lean manufacturing through factory design. He also holds a
B.S. in Engineering from Lehigh University in Bethlehem, PA, and an M.S. in
Engineering from the University of Michigan. To contact Jamie directly, go to
the web site www.leanlearningcenter.com.
Leading Lean: Ban the Hockey Stick!
April 22, 2009