Slowing down to gain output is such a paradox that resistance is often the response. Based on eight years of observing what goes on in most meat-processing plants, a universal goal has always been to get meat in the box. Obviously, getting product processed and ready-to-ship is the main goal for production managers. Too often, the problem is that how a management team gets meat in the box may be more wasteful than productive. Moreover, the natural response for more processing is faster processing. The difficulty is that faster usually means more mistakes. When we put our Lean Thinking hat on, more rework, more problems and more waste is not the path towards more "meat in the box".
I propose that slowing down productions’ pace will ultimately increase the amount of product put through the line. Typical responses to suggestions to slow down are drowned out by a chorus of management and supervision that says, in essence, "we can’t slow down; we have so much to do that we must speed up". The Lean response to this chorus of resistance starts back at the goal: meat in the box.
Efficient, effective production
All principles of Lean thinking contribute to efficient and effective production. Most importantly, for production efficiency is the principles of flow and pull. Flow is a production rhythm. This is product moving continuously at a rhythmic pace. Stopping and starting, or batch and queue, are the opposite of flow. Pull is a customer-based principle. Pull affirms that production starts with an order. How fast and by when the ordered product is pulled through the production process is called takt time. Clear evidence of flow and pull variance are over-production, over-processing and rework. Instabilities or variance in work processes leads to more effort for less output.
Over-production is the worst of all waste. Meat processors have long made money by making product today, freezing it and taking in big profits later. This business strategy should be revisited given the current global and national economy. Consider whether or not it is really profitable to place meat products in the freezer on the speculation that there will be a market day that brings returns that outweigh the costs.
In over-processing the workers cut larger portions than needed. Workers may add extra spices or trim excessively. Over-packaging can occur with additional paper, wrapping or thicker millage than required. Sometimes production workers weigh precisely when there is substantial tolerance or exact weights are not in the specification. Or the reverse may be true and "give-away" is out of tolerance. In short, more effort or material is put into a product than is required.
Rework is a term that describes processing needed to correct mistakes. Rework results in additional time, material and labor costs. Rework results in lower net productivity. The reasons for rework, overprocessing and over-production are numerous.
One factor that is often the culprit is excessive speed. More speed than is warranted creates breaks in flow. Furthermore, a production run does not have to go fast if there is no order (pull) for the output. For example, bottlenecks results occur when the grinder, sausage stuffer or bacon slicer is producing more product than wrapping, labeling or packaging can handle. Slow down the fastest machine. Observe if other equipment and workers can more efficiently keep up the pace. Most importantly, measure output and rework for that line. Output and rework should demonstrate an inverse relationship if the slowdown is effective. Less rework and more output in the same time frame should prove the old adage "slow and steady win the race".
An example of this phenomenon occurred in several lines of a recently audited ground-beef plant. The most significant gains came on two lines that made 4 oz. hamburger patties for a fast-food chain. These were fresh patties produced by machine five at a time. The pace was set by the forming machine. The next step downstream from the patty former was a worker who had to stack the patties 10-high, reform the row of five down to four and then slide the 40 patties into a bag. The worker downstream from the patty former worked at a frantic and constant pace. More often than necessary, the paper inserts would become misaligned, pieces of hamburger would retard the slide motion and other things would go wrong. Paper was trashed.
Patties were held on a side table hoping for reentry into the flow. The worker could not have been more dilligent in his work, but output was significantly compromised by the amount of rework. The most obvious constraint was the operator’s manual actions needed to get the size of the five formed-patty row down to four. It was a difficult maneuver and sometimes the stack would fall or spill onto the floor. The clear engineering fix was for the former equipment to make the same number of patties that were needed for bagging. This is a possibility, but it is costly and takes equipment out of service. What worked was slowing the patty forming machine down.
This example illustrates flow. The line can only go as fast as the slowest work action. The pace has to be in rhythm with the full-line operations. It might seem intuitively obvious that faster means more output, but remember that output should also be compared to rework and other wastes. On the wall in my workshop I have a quote posted. The quote says "the hurrier I go, the behinder I get". A true measure of productivity includes all factors, output and waste. The better measure therefore, is net pounds per hour of meat in the box.
Dr. Glen Miller is Senior Lean Consultant for Performance Essentials, Inc. More information can be obtained regarding Lean Manufacturing at www.performanceessentials.com.We would like to hear from you — to comment on this story or to request reprints, contact us by e-mail at: firstname.lastname@example.org.