Trending SPC Discussions

How to measure Process capabilitiy (Cp/CpK) for non-normal distribution?‎

The formulae widely used is based on Normal distributiion curve. But, we have seen processes which are completely different in terms of distribution. In those cases, how ‎ ... See More

In machining processes, for geometrical parameters what should be the Cpk/Ppk requirement?‎

How many points do you need to define for the rectangular command?‎

How many years of data do you have available?‎

What is the meaning if you find that the cp or cpk value less than 1 ?‎

Did we achieve or get CPk, PPk or Cmk value for unilateral tolerances? If yes please explain. ‎

 

Answer added by  Abdelkrim TRABELSI, Ingénieur Projet, Zodiac
11 years ago

How is process capability (Cp, Cpk) estimated for non-normal data?     First, we should discuss some general requirements for Process Capability Indices (Cp, Cpk) 1. You ... See More

 

Answer added by  Harikiran Rao, QA/QC Manager, Polypipe Middle East FZE
11 years ago

Process Capability enables you evaluate non-normal process capability using:  Box-Cox power Transformation  Johnson Transformation system  Clements Method using Pearson C ... See More

 

Answer added by  Ahmad Khreasat, Risk and Quality Officer, Royal Scientific Society - Policies & Risk Dept.
11 years ago

Actually you can't use Cp and Cpk on non-normal distribution. the forrmula is based on the assumption that the distribution is normal. thats why when we explain proc ... See More

 

Answer added by  pankaj Chaudhary, Quality Control Engineer, Jbm auto
6 years ago

SPC is a widely used quality tool throughout many industries. ... By monitoring and controlling a process, we can assure that it operates at its fullest potential. ... da ... See More