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Beware High Tech Sirens In Manufacturing

Phoenix Systems is joined by an unlimited number of manufacturing experts training for statistical literacy and process control implementation. Phoenix Services, the W. Edwards Deming Institute®, and Harbour Consulting are three such organizations, each dedicated to improving manufacturing methods and results. Phoenix Systems has been working with manufacturing operations at every level, from the corporate staff to plant managers, to machine operators and skilled trades persons.

Phoenix Systems and Phoenix Services have worked extensively with companies that have spent great sums of money over the past 4 decades to improve the statistical literacy of its workforce. Recent experiences have highlighted leadership’s need to continue leading their organizations to embrace these principles, to understand their processes, and to listen to the voice of the system.

High Tech Sirens In Manufacturing

Ok, I’m using a common word, but intending uncommon meaning, so allow me to clear that up immediately. The common meaning of Siren is a loud horn or warning device.

The less common meaning is from Greek mythology, “a sea nymph, half-woman and half-bird, who was believed to sing beguilingly to passing sailors in order to lure them to their doom on the rocks she sat on”.

Consider this scenario. Phoenix Systems experts have trained your machine operator to manage 500 process inputs and variables to create the most robust manufacturing process for your widget, increasing uptime and decreasing failures, scrap and rework.

The slide adjustment and cushion pressure of a metal stamping press, two key set up variables, are established during die tryout and confirmed using Formability Analysis executed The Phoenix Way. A recipe is established and documented on a set up sheet and stored in a file or three ring binder.

This manufacturing process includes equipment that was created by several different companies. This equipment may include crude means to set up variables (a scribed mark to indicate the physical location of a die gauge). It may include high tech means (a library function in a computer that stores a ‘recipe’).

While the high tech solution appears to be an advancement in process control, observations made by Phoenix Systems and Phoenix Services experts suggest the opposite. On its own, this library function is actually one of the biggest threats to manufacturing process control today. It’s a temptation that has proven too great for many to resist. It is the modern version of the Sea Siren, luring machine operators to ‘crash on the rocks’.

That system relies on the library values to be controlled. Phoenix Systems and Phoenix Services experts observe operators changing library values in response to special cause variation that doesn’t exist during the next production run. We’ve seen operators change the library values in response to variation whose source they haven’t even identified. This is the worst form of output control masquerading as process control.

The library function is a high tech siren, tempting your operators just like the mythical sirens of sailing lore that attracted sailors with unreal promises while distracting them from the threats (Rocks!). Operators have unreal expectations of the recipe’s accuracy and performance and don’t see the threat posed by making changes to the library function every time they experience bad results. Eventually the manufacturing process is unable to run, experiences high scrap and rework rates, and the operator is convinced the cause is incoming material from a supplier.

In most manufacturing settings, there isn’t any control over setting the library values. If you have the ‘keys’ to the press, you have permission to set new library values and the old values are lost forever. Most managers are unaware of this behavior in their organizations.

If the library isn’t controlled, it becomes a new version of an old tactic called Last Panel, where processes are set to recreate the last run. See the Deming Nelson funnel exercise for a simulation of this flawed strategy.

Recipes, within a broader process control strategy, are effective. High tech tools that support re-setting to your recipe can be a great tactic, but you must apply controls that carefully manage the processes by which these tools are employed so you don’t lose the desired benefit.