Sridhar
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Sridhar replied to the topic cusomer satsfaction survey analysis in the forum General 20 years, 6 months ago
Hi Erik,
Tahnks for the reply. I did try this method, but the problem is most of the cells i got or less thank 5 and i dont know what to do. Can you suggest what to od if i have celss less than 5.
Another question is because i am having all the combinations can i apply ANOVA(DOE) to fine out which plot and which grade gives me…[Read more] 
Sridhar replied to the topic Working out the TO BE Zst value in the forum General 20 years, 6 months ago
Hi,
I dont think you have to wait for 220 tasks, because any way you are converting them into defects per million opportunities. If it is 220 or less it doesn’t matters, the final metric you are going to say is defects per million opportunities.
sridhar

Sridhar replied to the topic FMEA Case studies in the forum General 20 years, 6 months ago
Hi chandra,
Send me your mail id.
sridhar

Sridhar replied to the topic why 3.4 parts per million ? in the forum General 20 years, 6 months ago
Hi,
This 3.4 comes from the normal distribution curve. You check a stad normal distribution curve at 4.5 sigma value. Multiply the area outside this curve by one million you get 3.4. You may ask why we take 4.5 instead sigma.
Then 1.5 sigma assumed as long term shift. That is the process may shift 1.5 std deviations in the long term. T…[Read more] 
Sridhar replied to the topic statistical six sigma impretation in the forum General 20 years, 6 months ago
Hi,
Probably you did n’t get the right concept of six sigma. Six sigam implies that you are able to incorporate 6 std deviations in between your target (center) to the closet specification limit. Now when you say 5 sigma implies you are able keep 5 stad deviations in between your target and closest specification. This implies that your std…[Read more] 
Sridhar replied to the topic Normality Testing Question in the forum General 20 years, 7 months ago
Hi,
I think i will go with the Erick. For this kind of data it is better to do the contingency table approach. I am not sure whether i understand your question correct or not. I am trying to explain what i understood.
the resutls are
Large deals small deals …[Read more] 
Sridhar replied to the topic Tools to Prioritize Six Sigma Projects in the forum General 20 years, 7 months ago
Hi,
It is very simple but the only disadvantage is you know when you have around 10 things to prioritize you cant compare all the 10 at a time. Thats what we can avoid with avoid. It compares only pair wise and later on you can even check whether any bias is there in this scores. If so do it again until no bias. Yes it also have some dis…[Read more] 
Sridhar replied to the topic Tools to Prioritize Six Sigma Projects in the forum General 20 years, 7 months ago
Hi Antony,
can you send me your mail id, i will send you one paper and an excel sheet to do prioritization using AHP.
sridhar

Sridhar replied to the topic DOE with attribute response in the forum General 20 years, 7 months ago
Hi,
You have to take a transformations on the response data if it is of attribute type, depending on the distribution. May be in your case it may follows poission distribution. Take a transformation do the similar analysis as you will for continuous response.
You can look into minitab for this. Are you can go through this…[Read more] 
Sridhar replied to the topic Prioritization Diagram in the forum General 20 years, 7 months ago
Hi,
Try with AHP ( Analytic Hierarcy process ).
sridhar

Sridhar replied to the topic How many sample should I take…. in the forum General 20 years, 7 months ago
Hi,
Sample size calculation depends on the following factor.
1. Your confidence level
2. Margin of error
3. Std deviation of population ( in case of proportions it is sqrt(p*q)
Once you assumed these values calcualte the sample size as
n = Z^2 * std deviation / (error)^2
The final decision on sample size depens o…[Read more] 
Sridhar replied to the topic Tools to Prioritize Six Sigma Projects in the forum General 20 years, 7 months ago
Hi,One way of prioritizing is AHP (Analytic Hierarcy Process). The concept is comparing at a time only two characterstics i.e. pair wise comparision. All the pair combinations are compared and given a score on a scale of 1 to 9. Once all the combinations are over then we standardize the scores get the most important ones. One more advantage of…[Read more]

Sridhar replied to the topic Justifying outlier in the forum General 20 years, 7 months ago

Sridhar replied to the topic Calculating Cpk using Japanese Method in the forum General 20 years, 7 months ago
Hi,
This is just the manipualation of the formulas. I will prove the calculations.
Cpk = min { USLAverage/ 3*sigma , Average – LSL / 3*sigma}
Cp= (USL – LSL)/6*sigma
sigma = (USLLSL)/6*Cp
Putting sigma in Cpk equation
Cpk=2*Cp/(USLLSL)*min{USLAverage, AverageLSL}
= 2*Cp/(USLL…[Read more] 
Sridhar replied to the topic How to Identify Maverick lots statistically in the forum General 20 years, 7 months ago
Hi,
Box cox method is used to make the non normal data to norma.
You can go through this handbook
http://www.itl.nist.gov/div898/handbook
this gives you some information about the box cox method. After that you can use any statistical pakcage like MINI TAB etc which will do the transformation.
thanks
sridhar

Sridhar replied to the topic How to Identify Maverick lots statistically in the forum General 20 years, 7 months ago
Hi,
Why dont you try for some transformations like Box – Cox. Generally this transformation makes the data closely to normal. Then you calculate your control limits and convert back to your original values.
sridhar

Sridhar replied to the topic Determining Sample Size in the forum General 20 years, 7 months ago
Hi,
The simple formula to calculate the sample size is
n = Z^2 * p*(1p)/(error)^2 for infinite or very large population
If you have a finite population make the correction as below
Sample size(for finite population ) = 1/{(1/n) + (1/N)}
n= same as calculated by the above formula
N = Populat…[Read more] 
Sridhar replied to the topic new technology evaluation criteria in the forum General 20 years, 7 months ago

Sridhar replied to the topic When to use Cpk or Cp to determine the six sigma value? in the forum General 20 years, 7 months ago
Hi,
Always use Cpk for six sigma calculation. When your process is at target then both Your Cp and Cpk are same. Cpk is always less than or equal to Cp. Use Cpk for six sigma calculation.
thanks
sridhar

Sridhar replied to the topic FMEA Case studies in the forum General 20 years, 7 months ago
Hi,
Send me your e – mail i will send you two papers.
bye
sridhar
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