S.M Junaid is the Production Manager of Procon Engineering Pvt (LTD) from Karachi, Pakistan. He periodically shares kaizen examples with us. His previous contributions can be found here and also here. Today’s kaizen example is titled “Elimination of Rework Muda in Stamping Parts”.
The following are the observations and the vital reason of defect / rework MUDA which has been observed during production of sheet metal components.
Dies tempering (heat treatment) is a basic requirement in the manufacturing of dies specially piercing punches, bushes and cutting edges. We are going to cut or pierce a metal by another metal.The tool metal must be harder than the cutting metal, so the cutting tool should be properly tempered. Lacking this in tool manufacturing increases burrs in sheet metal parts trim edges and piercings. This ultimately results in to rework MUDA in production because the customer (assembly lined) needs burr free parts.
What is more interesting is the realization that the COPQ or Cost of Poor Quality is often much larger than it first appears. Typical elements of the COPQ include inspection cost, testing cost, rework cost, customer returns etc. However there are many other costs which are not traditionally measured as part of quality cost, but significant nonetheless. Junaid came up with the COPQ Iceberg to visualize this.
“Defect MUDA is like an ice berg where the hidden portion of ice berg is larger than the visible portion. The hidden portion is more dangerous than visible portion so there is a need to eliminate the hidden portion of Ice berg to save our journey toward MUDA elimination.”
This is a great application of the lean principle of “making problems visible” to the important topic of the cost of poor quality. It’s important to take a deep breath and dive deep to see what is beneath the surface.