Elbrin

  I am surprised everyday at the number of so called “Certified” Six Sigma Black Belts, Green Belts and Master Black Belts that don’t understand the most basic principles of Quality Improvement.  Add to that the absolutely inept leadership so prevalent in American business today, and you have the situations alluded to previously in this th…[Read more]

I hate to give the default answer, but “it depends”.  How variable is your current process?  How senssitive do you want to be to “POSSIBLE” assignable cause?  How quick do you need to respond to “POSSIBLE” assignable cause?
I would say if you are just beginnig to look at this process, start with rule #1 and if you have points that break this rul…[Read more]

IE
 These are the very type of questions that the DAMIC methodology is designed help us find the answers to.  Stock-out vs. excess inventory is a sinsative balance.  My first question back to you would be, is it a constraint, meaning are you missing delivery dates, losing sales, or building up WIP down line due to these stock-outs.  If so the…[Read more]

Richard,
It sounds like you have 2 numbers to deal with, you have a $60000 hard savings.  How the owner chooses to spend that additional hour will determine what other claims you can make.  I would provide him with alternatives.  Such as, an ower of this kind of business is often involved in sales.  How many hours does he spend making a sal…[Read more]

Follow up questions:

Has your leadership provided clear goals (e.g. $XX cost out, Decrease cycle time by X%, Reduce defects by X%?) If so base your pareto on these.
What current data sources are available that you can leverage?
Are there business units that are more willing partners than others?
Are there any quick hits that would not…[Read more]

Tommy, Everyone
MiniTab has an excellent help menu and even better online technical support.  I suggest you use it.
https://customer.minitab.com/

 I am no authority on automobile quality measures, but I have always been suspect of these reports.  If I understand correctly the ratings are based on counts only, with no calibration for the severity of the defect.  So the compliant can be anything from a squeak to the engine dropped out the bottom, and they are counted the same.  If the qua…[Read more]

Case and Point

Cpk requires a clearly defined spec. limit, most service processes do not have this.  If it is truely important to the overall performance of the orgainzation, get your leadership, better yet your customer, to establish these limits.  If not quit doing it, it’s waste.  Either way it requires leadership to make a decision, good luck.

EdG,
I understand that the nature of web forums often dictate how and what questions get asked.  I was not basing my statement solely on posts to this board, but what I observe from belts in the field and in training.  I see too much focus on generating multiple charts that all say the same thing.
Just my thoughts….

R squared is a goodness of fit for the estimated regression equation.  Sums of Squares Regression/Sums of Squares Total.  Simpley put how much of the total variation can be attributed to identified factors (Between) vs. error (Within).  R squared adjusted is basically the same taking into account degrees of freedom.

JR,
I am not suprised to hear that Toyota would embrace Six Sigma as a methodology.  As a world class leader and inovator in Continuous Improvement I am glad to hear they are integrating Six Sigma with the Toyota Production System a.k.a. Lean.  I must admit I envy you working for such an industry leader.

Forget about the control charts if you are not meeting your customers demands it does not matter if your process is in control or not.

davchr,
It sounds like you are asking this in the context of monitoring the performance of a process, rather than seeking improvements.  You are really the best person to answer that question.  You know your process, logical sub-grouping, and random sampling techniques are key to intellegent data analysis.  If 32 consecutive samples is not re…[Read more]

 The answer of whether control charts are robust to normality issues or not is, “It Depends.”  How precise do you want or need your control charts to be?  I personally always use Individual and Moving Range charts together.  If short term variation indicates an unstable process, the individual chart is of no use.  If however the process is stable…[Read more]

Brit,
 Median is used to describe central tendency in non-normal data, because of outliers.  A single extreme outlier can significantly skew the mean, but will have little effect on the median.  Variance, Range and Standard Deviation are still used as dispersion measures for non-normal data.  Non-parametric tests such as Mann-Whitney and Kur…[Read more]

Mike,
This discussion seems to have broken down into personal attacks.  Your ability to pull a single line from my post and explode it way out of context is a bit disheartening.  With this sort of ability I am sure you would make a great politician.

IE,
This is a classic Theory of Constriaints exercise.  Without addtional information it is difficult to offer any meaningful advise, however, if the machine is the constraint to your process, this is where you need to concentrate your efforts.  Exploit the constraint, Subordinate everything to the constriant, Find ways to Elevate the co…[Read more]

I am unclear, are you looking to improve your Rma process, or reduce the number of returns due to product defects?

Do not choose one over the other.  These are not conflicting approaches, they are complementary.  Use SS to Define Measure and Analyze, when it comes to Improve and Control think Lean.  If you want an excellent beginers guide to Lean try “Lean Production Simplified”, by Pascal Dennis.