Want to know why PROCESS VARIABLES are important for manufacturing zero defects?

Manufacturing activity involves processes which are influenced by the Material, Machine, Measurement, Method, Man and Environment. Understanding the impact of the changes on the outgoing quality is the key to process control. Controlling these variables is the experienced way of assuring quality instead of the still traditional way of 100% inspection. I have listed the hints to understand the process variables.

  • Frequency of changing machine/equipment as well as material batch?
  • Frequency of change | tool | fixture/clamping | wear parts?
  • Frequency of resharpening  including wheel dressing)?
  • Frequency of measuring equipment change/calibration?
  • Frequency of operator | manpower changes?
  • Process Design for 100% First Time Rate after every change?
  • Validated zero repeatability error (100% FTR) during changing?
  • Process Control for 100% Every Time Rate inbetween the changes?
  • Validated with 100% checking over at least 3 days?
  • Upstream control (Tool Certification, Operating License, Controlled Ambience)?
  • Measurement for control practical during the maximum frequency?
  • Measurement trigger is robust?

Checking the FTR, ETR, Downstream Rejections and Customer Complaints will reinforce the importance of process variables.

Finally, recognising that each one of us can only influence the future and not the past is a strong motivator to start with the basics to understand the process variables.
Happy Reading!