@Strayer. Okay but is DPMO always long term? Does not it depend on your sample size? Otherwise both DPMO and sigma level are short term and no 1.5 conversion have to be carried out 3 months, 2 weeks ago
Looking back at these answers I am still interested why it is not poisson instead of binominal? 3 months, 2 weeks ago
One question regarding your example:
Example : Suppose that we have a process with this characteristic:
Units/shift = 30,000
Defective parts = 300
Defects observed = 350
Opportunities = 15
Dpu = 350/30,000 = .011
DPMO = (.011/15) x 1,000,000 = 777
Yield : 1-(0.011/15) = 99.9922%
ZBench : 3.164 *From normal distribution…[Read more]
Thanks for all your replies. At the moment we use a control chart just for analysis of a few weeks of production. Based on an histogram and a control chart we could determine out of control situations, variety within the control limits and track both back to certain X-s. You’re right that using output just for control without analysis is useless,…[Read more]
Two short questions.
If I want to create a control chart where I measure the output each hour, should I just use an I-MR chart as my subgroup is an hour? However, output can range from 0 to infinity it is still discrete measure. So i’m not sure.
The other thing is that my output per hour is not normally distributed.…[Read more]
Thanks for all your responses. Indeed, it depends maybe on your aim of making a SIPOC (and luckily no jail if you do it otherwise:)). In our case we have students carrying out a LSS green belt assignment in practice. As they are unfamiliar with the process to improve at the start of their internship, we think it is very useful to have a SIPOC like…[Read more]
I have a question/opinion regarding the SIPOC. I see often two types of SIPOCS in practice.
1) where people just define the main process steps, the inputs for all these steps en outputs for these steps.
I often regard it as very confusing and hard to understand where each input arrives in the process and where outputs leave the…[Read more]
Thanks! By the way, why is it based on a binominal distribution? Isn’t it about defectives (a part could have many ctq’s/defectives) which corresponds with a Poisson distribution? 2 years, 3 months ago
@straydog Thanks. Never thought about that. This implies that it is more and more difficult to achieve higher sigma scores, the higher your current score is. Am i right?
I have a question regarding DPMO. If you calculate DPMO, why would you want to look up the corresponding sigma level? And does it have any meeting as the DPMO can consist of multiple items with (often) non-normal distribution of some of these items. 2 years, 5 months ago