The quest for quality reliability has pushed manufacturing companies to continuously upgrade their processes and increase the capability to deliver uncompromising quality. What was considered a benchmark for high quality conscious companies is now a norm.“0 ppm” is no more an achievement but a given, strongly demanded and driven by OEM`s.
One day my quality and Manufacturing heads walk into my room to get a Corrective action report (required to be submitted to customer) signed by me. On reviewing the report one of the reason post 5WHY analysis was “operator mistake”, and training of operator provided as a corrective plan. That made me think.
I casually pulled on a few more CAR`s and not to my surprise, 38% of the CAR`s had identified “operator mistake” as either the main or one of the reasons.
I joined a large MNC as a manufacturing engineer. The company was rated one of the best in the cluster of vendors in the Customer ratings. I could sense the high focus on quality and pride people took in establishing quality environment. One day while reviewing the project on improving the productivity of a particular line, it was realised the bottleneck operation was the final inspection? That got me intrigued.
A VTR analysis threw up that the final inspector was supposed to verify the product at 37 places before placing it in the bin. Obviously, the line kept stopping after every few minutes and as a result, all the downstream operationsaligned to the bottleneck cycle time and thus impede the rate of output. On further probing and referring toquality concern reports from the same line, I realised, that for every quality concern faced at customer or identified during FMEA review, most prevalent ICA (interim corrective action) was to allocate the task of verifying to the final operator. As a result, over 5 years, the final check points increased from 13 points to 37 with a marker as a proof of check. Adding the fatigue factor (the part had to be checked in various directions and orientations), the average cycle time became approx. 45 second, while the next bottleneck operation cycle time was hardly 27 seconds. This was atrocious, pulling down the line capacity by almost half.
What happened Here?
While the cross functional team was extremely conscious on shipping a good quality product with a single-minded dedication to protect customer (the teams were under pressure to obtain 0 ppm status with OEM, as it affected their incentive), the company missed on the basics – reliablemistakeproofing.
This might be scenario with many companies, where in quality assurance plays a big role in establishing outgoing quality and top management projecting the quality performance at end customer as an achievement while internal processes are heavily undermined with waste of inspection, too much of setup, high internal rejections, and reduced line rates etc. Surprisingly, the final inspector tuns out to be one of the most important skill in the skill matrix.
Typically, when a quality defect occurs or is identified in the process, the standing guideline must be to address it through a simple, reliable mechanical inline poke yoke.
Next step is to ensure that there are reliability studies done on the Poke yoke installed. The Poke yoke verification process should be defined and that should make part of management quality review process.
One of the measures could be %age of potential failures covered through Poke yoke, and out of that % that is covered through mechanical poke yokes that needs least maintenance.
All corrective actions termed as “inspection point added” must be treated as an ICA and all active ICA to be part of management review.
Cost of installing an ICA should be captured and highlighted in terms of increased cycle time, increase in headcount, or increase in rejections or number of deviations approved.
As a philosophy,special appreciation awards must be constituted for simple, economical, and mechanical Poke yokes. Remember,simple is easy to maintain.
Teams must take targets to eliminate “number of inspection points” till it comes to “zero”.
Move away from terms like” operator to be trained”, this sounds more like excusefor a poorly designed process with low controls. When processes start being defined by operators, they are no more self-certified and thus do not have long term reliability.
The variability of manpower must be brought down as a campaign and as part of Quality culture.
To reach the pinnacle of quality, move to a self-certified quality process than to quality assured.
About the Author
Mr. Vibhas Raina
Project Director at Mind
( A subsidiary of Great Wall Motors )