• It has not helped them in avoiding the dismal status… so should we stop using six sigma for process improvements? I would do that if anyone can share something that’s better…
    any help??

  • Very interesting topic… thanks

  • Hemanth replied to the topic Roll Throughput Yield in the forum General 12 years, 6 months ago

    RTY = Yield of process 1 x Yield of process 2
    Let us say you have casting and machining operations. You start with 100 units of which 80 pass through Casting (80% yield). Of these 80 units (passing through casting) only 64 pass through Machining operation (again 80% yield for machining operation). Your RTY = (80/100) x (64/80) = 0.8^2 = 0…[Read more]

  • Y= Phase screening effectiveness for system test or Requirement Screening effectiveness
    Data element: No of defects (or requirements) found during System test / Total no of defects (or requirements) found during System test and thereon
    You can do a MSA on defect, to ensure everyone understands the definition correctly. Since defect as such is…[Read more]

  • “How do we check relation between causes & effects, & which cause is most critical among causes?”
    Hemanth: There are quite a few tools but mainly regression analysis and Design of Experiments can help you check cause and effect and also the most critical one’s. To know which causes are more critical I would suggest to conduct DOE’s.
    “What do we…[Read more]

  • Hi
    In all the cases the degree of freedom is 5. Let us understand the concept of degrees of freedom. It is the possible values we need to know about a population whose mean is known (this is an assumption which is always made in statistics but often neglected). So in our case where we have 6 outcomes with a know mean (i.e. 4) you only need to k…[Read more]

  • I feel, you should evaluate the success internally based on the success factors that you would have established during the initial days of deployement. One very important criteria (my thoughts) for decentralisation is six sigma has not only provided significant business results but also has changed the business processes in such a way that Six…[Read more]

  • Hemanth replied to the topic Top 10 topics in the forum General 13 years ago

    Thanks Stan
    I will try these out sometime.

  • Hemanth replied to the topic Top 10 topics in the forum General 13 years ago

    No shortcuts, though below are few items that will help you understand most of the stuff if known in depth:
    1. DMAIC
    2. ANOVA
    3. Normal Curve / probability distributions
    4. Quality Function Deployment
    5. Statistical Process Control
    6. 7 QC tools
    7. Measurement system analysis
    8. Read book by Elliahu Goldratt (The goal is the best…[Read more]

  • Hi Vinod
    Hope your DOEs are coming along well.. in case they are not..try doing this (I should have suggested this before, its been a long time I left manufacturing…)… start collecting data on each part and record all the parameters (that you can) against each part…once you have sufficient readings (may be 50 – 100) you can just compare the…[Read more]

  • Hemanth replied to the topic Chi-square test? in the forum General 13 years, 5 months ago

    Chi Square is the counterpart for ANOVA… it achieves the same purpose as ANOVA does for variable data.
    Chi Square analysis is useful when you have the discrete response and more than 2 levels to compare (eg: defect rate for Material A, B and C).
    There are other applications for Chi-Square, like dependency testing as suggested in one of the…[Read more]

  • Hi Catherine
    That is painful… I do agree that identifying someone from inside for such roles helps but this is no excuse for calling people for i/v to show that they are i/v’ing people from outside as well…
    I am convinced if one is good it is just a matter of time till he/she gets what they deserve… not many agree with me though, but I do…[Read more]

  • Regression is a dangerous tool, since the data is taken in an uncontrolled environment (the only advantage over DOE). You might want to check two points before accepting the model and the decision of how many samples required to get two separate values for Y with same value of X.
    1. Normally a parameter whose second order has relation with…[Read more]

  • Hemanth replied to the topic OTD and Lead Time in the forum General 13 years, 6 months ago

    Hi Nizar
    Glad the post was helpful.
    This one’s a trick question  (if you really dig deeper)..
    On time delivery (% lots delivered on time) is a Y for sure from define phase.
    Lead times for each process step is (as I call it) Low level Y. So if we measure these for each process step (as part of measure phase), obviously steps which have higher…[Read more]

  • Hemanth replied to the topic USL in the forum General 13 years, 6 months ago

    Please do not be..!!
    I agree with your post..two replies are better than one..!!

  • Hi Vinod
    I agree with the previous post you can still do the DOE, try working towards creating a more variable data, eg: we did this with wrinkles (if I remember this correctly, its been a long time), we used to look at the number of wrinkles rather than just a good / bad response metric. Also, you could use options like area as another metric…[Read more]

  • Hi
    Another example could be taken from any software project:
    Deliverable: is the working software product that meets the customer requirements, delivered on time and within budget.
    Output: the requirement documents, design documents, planning documents, MOMs training material (if not specified as part of deliverable), SOW, contracts etc
    KPOV:…[Read more]

  • Hemanth replied to the topic OTD and Lead Time in the forum General 13 years, 6 months ago

    Hi Nizar
    The answer lies in your question. In define phase you could look at the ontime delivery (% lots delivered on time) and in the measure phase look at the lead times (with a break up for each process step) for the entire process. This will help since you would have better information in form of variable data at the same time measure your…[Read more]

  • Hemanth replied to the topic USL in the forum General 13 years, 6 months ago

    Hi Abhishek
    Either I didnt understand the question right or the world has gone ahead since I last visited the forum.
    But nevertheless I would still go ahead and share my thoughts.. any time you are setting an expectation with any process (be it USL or the acceptable limit), you have to consult the customer. I dont know why you want to…[Read more]

  • Hemanth replied to the topic Criticisms of SS in the forum General 14 years, 2 months ago

    Hi Samir
    I agree with you it is very essential to ensure the current process baseline and agreement on data collection mechanism before moving to analyse phase. Though the Grasp and Appreciate… step comes after the Analyse phase in the roadmap you shared.. and hence the question in my previous post…

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