Forum Replies Created
Forum Replies Created
August 26, 2009 at 4:41 am #185003
Completely agreeing with Sandoor… also as you mentioned 45secs is only on the assumption that all these 5 people work on a sequential process. if the process are parallel or a combination of both then individual timings will be completely different. Also one needs to include necessary wait/travel/setting/down etc. times into the process.Definitely needs more info and understanding to give a final answer.0August 13, 2009 at 10:58 am #184829
i wouldnt say that…in fact some links e.g. “Find a Job” are not working at all as of now 13th Aug 10:30AM IST. Although the discussion forum link is up but its way too slow for smooth reading and posting. I am an indian but currently accessing it from Srilanka behind my office firewall.0June 17, 2008 at 12:32 pm #172889
Check, if cost of air travel is linked with lead time of booking the tickets. If “yes”, then frame your problem statement around it.0February 4, 2008 at 8:28 am #168125
If 1000 pepole lie instead of 100 that does not make it the truth.0September 19, 2007 at 5:40 am #161415
Please do send me the tool at [email protected]
Thanks in advance0September 13, 2007 at 4:41 am #161060
Definetely… Six Sigma if applied in letter and spirit will help everywhere and anyone….0August 3, 2007 at 5:43 pm #159536
But in some situations even with samples more than 30 the data may be non-normal, in that case how can one use Z-test. I am sceptical of such thumb rules. One can not generalise all processe this way.
If all we work with are samples(which are supposed to follow t-distributions) and never populations then wy this Z-Test at all???
An what about 2 sample Z-test???
0July 17, 2007 at 11:24 am #158759
Anyone else would like to give his thoughts on AC?0July 16, 2007 at 5:13 pm #158713
Thanks for all your responses. they have really been infomative and useful.0May 29, 2007 at 8:53 am #156685
If the average price for a home is X dollars, half the houses will always fall below average and the rest above.
Cheers DD0January 31, 2007 at 7:50 pm #151349
the characteristic I’m measuring is time to perform the process.
I did think of using a histogram to summarise, but while this might be good pictorially, I also wanted some stats to add weight to the summary; what can you put with a histogram, other than min./max., mean, and comment on shape?
regarding stratification on a single control chart, how do you do this on minitab?0January 31, 2007 at 3:52 pm #151326
I think I might be able to answer my own question after reading your replies and more thought – how about using boxplots to combine the data – they show things statistically without corrupting the truth?
0January 31, 2007 at 3:01 pm #151324
there will actually be several charts for several people at one location, several charts for several people at another. I want to summarise statistically, if possible, how the overall process is currently performing before I introduce a change, then repeat the data collection and summarise statistically the overall improvement.
I get the point about keeping the charts separate, but the stakeholder is going to somehow want to see all the separate charts and data summarised to indicate the business benefit of introducing the change.
This is what I’m struggling to get to, any help appreciated thx.
0January 31, 2007 at 1:49 pm #151321January 31, 2007 at 1:23 pm #151320
so if I time order the data, and then combine the 2 data sets accordingly (i.e. data points will jump from op. A to B etc. as the tests will be done roughly at the same time) to produce a control chart, it is statistically valid even though the readings weren’t taken at the same place?
and if the answer is yes, then my control limits, standard deviation and mean are valid also?0January 27, 2007 at 9:46 pm #151160
thanks for your last post, it definitely helps, you have also helped in another way;
I looked up pretest/post design and also the Hawthorne effect;
if they are doing the process 2 / 3 times a day, and knowing that the process can be simulated in a ‘classroom’ setting, I could get their supervisor to ‘time’ them do the process 2 / 3 times at the start of each shift (in the classroom), then leave them to get the actual data for the shift.
This would constitute quite an effective control I think for when people ask me that ‘difficult question’.
and thanks again
DD0January 27, 2007 at 8:16 pm #151156
Thanks to both of you.
The average time is 10mins., quickest 5mins., worst case 40 mins., and the new tooling should enable the proces to be done consistently in less than 1 minute.
Please help with the estimation of standard deviation if you can.
Regarding random sampling & quasi-experimental design, the process is done 2 / 3 times a day, so I was planning on getting 10 people at 3 different sites (as per Sandor’s post) to take the data over 3 weeks (to give the 30 data points per person), then repeat with the new tooling.
This I think does not qualify as random, but the problem is I am time limited and need to complete the study within the 6 weeks.
So maybe I need to explore the quasi-experimental design in more detail as suggested, unless you can advise further.
0January 27, 2007 at 1:40 pm #151146
Thank you Sandor,
I think I get what you’re saying. Because I have 30 people each taking 30 data points (in this case, time to do the process), that one site should be well represented, assuming there are no special causes, like time of year, shift etc., which in this case it is safe to assume there aren’t.
I similarly don’t see reasons why this site should differ greatly from the others, I could perhaps screen this by asking a set of questions to the other sites, as a justification for not including them on the test.
At the end of the day I asked the stakeholders if they wanted one site only or multiple sites, their response was ‘one would be easier’.
I just wondered about the ‘margin of error’ rule of thumb, where a survey of 50 could have a 14% error, not sure that applies in this case though, perhaps you could help confirm this?
Thanks0August 29, 2006 at 2:33 pm #142453
Were you from Omnex Chennai earlier?
DD0February 16, 2006 at 8:46 pm #64223
As your deployment gains more traction, you will find it difficult to use spreadsheets. At my company, we built an internal system but eventually recognized that we could not easily implement it enterprise-wide. Consequently, we used a cross-divisional team to develop the criteria for evaluating Six Sigma project tracking systems.
Based on our requirements, we identified three companies and ultimately decided to use PowerSteering because their system was customizable and flexible to meet our current and future needs.
Remember, no two Six Sigma implementations are the same; therefore, I recommend that you decide on a system that can to more than track projects.
DD0April 5, 2005 at 6:02 am #117227March 10, 2005 at 5:02 am #116179
I fully second that. Its totally baseless to assume the 1.5 sigma shift and adams theory has no grounds
DD0October 8, 2004 at 6:56 am #108721September 23, 2004 at 9:17 am #107816
Once you have decided to transform the data after thoughroughly undrestanding your process characteristics(assuming there is no other way of getting the normal distUse a Lambda of -0.5 as it gives you a better transform into a Normal dist(see below) I have used Minitab14 to get this
N N* Mean StDev Median Minimum Maximum Skewness Kurtosis
16 0 2.8 3.19186 1.25 0.5 11.4 1.77312 2.65146
Box-Cox transformation for Normal distribution: Lambda = -0.5
Goodness of Fit Test
Distribution AD P LRT P
Normal 1.575 (<) 0.005
Normal (After Transformation) 0.376 0.369
Lognormal 0.440 0.255
3-Parameter Lognormal 0.816 * 0.001
Exponential 0.646 0.304
2-Parameter Exponential 1.169 0.032 0.013
Weibull 0.633 0.088
3-Parameter Weibull 0.377 0.432 0.000
Smallest Extreme Value 1.956 (<) 0.010
Largest Extreme Value 1.224 (<) 0.010
Gamma 0.723 0.074
3-Parameter Gamma 0.260 * 0.000
Logistic 1.321 (<) 0.005
Loglogistic 0.449 0.217
3-Parameter Loglogistic 0.650 * 0.001
ML Estimates of Distribution Parameters
Distribution Location Shape Scale Threshold
Normal* 2.80000 3.19186
Normal (After Transformation) 0.87116 0.39277
Lognormal* 0.50351 1.03606
3-Parameter Lognormal -0.73721 2.48225 0.49500
2-Parameter Exponential 2.30500 0.49500
Weibull 0.99052 2.78697
3-Parameter Weibull 0.54634 1.47157 0.49500
Smallest Extreme Value 4.54748 3.90589
Largest Extreme Value 1.55563 1.76479
Gamma 1.08674 2.57651
3-Parameter Gamma 0.41591 5.54211 0.49500
Logistic 2.18928 1.55931
Loglogistic 0.43032 0.60239
3-Parameter Loglogistic -0.42644 1.40205 0.49500
* Scale: Adjusted ML estimate
Here is the transformed Data
WLR Transformed Data Back Transform11.4 0.29617 11.44.6 0.46625 4.68.3 0.34711 8.32.9 0.58722 2.95.7 0.41885 5.70.7 1.19523 0.70.7 1.19523 0.70.8 1.11803 0.81.1 0.95346 1.12.2 0.67420 2.22.4 0.64550 2.41.1 0.95346 1.10.5 1.41421 0.50.5 1.41421 0.51.4 0.84515 1.40.5 1.41421 0.5
To Transform it back I have used the calculator functionof minitab using the formula ANTILOG( – 2*LOGT(‘Transformed Data’))
Hope this helps
DD0August 4, 2004 at 12:01 pm #104985
Whats your problem dude?
DD0July 29, 2004 at 1:37 pm #104613
Not every six sigma tool may be of high value in construction. (I can’t see a DOE, for example.) But the philosophy and some of the tools can be brought into play.
A couple years ago, I interviewed for a six sigma position with Neumann Home Builders in Illinois. They wanted somebody to plan their processes for getting people into their new homes, etc. I don’t know if anything ever came out of it, but here’s a lead for you.0July 29, 2004 at 1:30 pm #104610
To me, Six Sigma is a philosophy and a set of tools that can be used in a variety of functional areas to address waste.
Supply Chain Management (SCM) is a function. (And it can be a very tough function! Suppliers can be very tough to work with.) Six Sigma can be used in SCM, just like it can be used so many places.
0July 6, 2004 at 4:47 am #102956July 4, 2004 at 8:16 pm #58161
Your question is a bit broad. Immediate answer is to gain support for SixSigma from the leadership. But I’m not sure if youcurrently have responsibilty for SixSigma or if you knowing the benefits of it simply have the view that it can help to improve the business. Please be bit more specific so that the advice can be of merit to help you.0May 20, 2004 at 1:50 pm #100530
On eyear or three years, depends on how your company wants to make the determination. My comapny uses one year savings in all aspects.0March 29, 2003 at 5:54 am #84290
A good question indeed. There is no harm in going from 6 to 7 og 8. In fact airline industry operate at 10 or more for flight take off & landing, but for all practical purposses in an industry where humal life is not at risk six sigma is a good enough improvement benchmark.
More than that may not be worth the Time, money$$ and effort.
Thats my take, Hope it answers your query.
DD0February 20, 2003 at 5:22 am #83122February 18, 2003 at 6:15 pm #83076February 18, 2003 at 5:44 pm #83073
In much the same way as it is done at other places. Start with a problem statement and apply DMAIC methodology to attack the problem.
let me know for further help.
Regards0February 13, 2003 at 7:45 am #82962
Std. dev.=SE Mean/sq.root(number of samples)0August 6, 2002 at 8:33 am #77866
Can you post your e-mail id so that I can send them your contact details. They will be in touch with you soon.
DD0August 6, 2002 at 5:19 am #77863
The Indian companies that are practicing Six Sigma I know are Wipro, Allied Signals, Texas Instruments, Telco… etc. to name a few. Also there are a host of multinationals using SS(e.g. GE, FORD) There is an expert cosultants to six sigma named OMNEX located in chennai who are consultants to Ford & its suppliers. I can send you the contact details if required.
Hope this helps
DD0July 19, 2002 at 11:52 am #77377
Yes as Gabriel says you can post it on his site. I am curious too.
Thanks for sharing
DD0July 10, 2002 at 6:18 am #77091
MheIts not as arbitrary as u posted this. This site is fully devoted to some six thing you r takling about. Please look aroung you before you leap.
Do some homework yourself, and then post any query that you may have.DD0July 10, 2002 at 5:22 am #77090
You have not made it clear weather you as an organisation is new to six Sigma or not. Anyway assuming that you people are new to it.
There are a lot of ways in which you can use it in HR. Basically Six Sigma can be applied anywhere where there is a process(in your case transactional) or product to improve an existing process(DMAIC) or setup a new process(DFSS).
Whatever you do at HR e.g Hiring, Pay, Personnel Database, Training, everything has a procedure and definetely a process is going on. You can work on improving the time, no to errors, rework..etc etc basically defects or you can implement a robust new process.
Hope this answers your query. In case you need more info you are welcome.