iSixSigma

Atkins

Activity

  • Atkins replied to the topic Histogram in the forum General 15 years, 5 months ago

    I usually take the range of the data and divide by 10 (cells).  The I take whatever the interval came up to be and round it off to something that will give me reasonable cell intervals (e.g., whole numbers in an ideal world).  The actual number of cells then is whatever that rounded number turns out to create.

  • Atkins replied to the topic Histogram in the forum General 15 years, 5 months ago

    I usually take the range of the data and divide by 10 (cells).  The I take whatever the interval came up to be and round it off to something that will give me reasonable cell intervals (e.g., whole numbers in an ideal world).  The actual number of cells then is whatever that rounded number turns out to create.

  • Atkins replied to the topic Special or common in the forum General 15 years, 5 months ago

    A simple tweak is unlikely to affect unassignable (common) cause cause of variation, but might instead introduce assignable (special) cause.  Since common cause variation is inherent to the design of the process it often takes more than just a tweak to reduce it.
    However, it all depends on what type of process it is, what kind of a tweak you d…[Read more]

  • As others have indicated, there are many BB certification, and most likely follow similar paths.  Which is best for you probably depends on what you plan to do with it.  If it related to a current (or future) employer, would they value one over another?  If it’s as a consultant I doubt it matters; if you’re certified you’re certified.  Cer…[Read more]

  • Stan is correct.  One of the classic books on SQC is Grant & Leavenworth, which consists of two major sections:  SPC and Acceptance Sampling.

  • Atkins replied to the topic True Root Cause in the forum General 15 years, 6 months ago

    Good point … good RCA requires both domain knowledge and problem solving knowledge.  In my experience each type of knowledge often should come from different sources.
    A domain expert will jump to conclusions based on their biases, previous experiences, last problem seen, etc.  The problem solving expert will not have sufficient domain e…[Read more]

  • Atkins replied to the topic True Root Cause in the forum General 15 years, 6 months ago

    There is nothing magic about the number 5 in 5-whys.  I’ve worked with situation that were 9-whys.
    Perhaps the best thing about the number 5 is that if you go that many levels, at least you’re not staying at the symptom level.  However, there is still a chance you’re still working at the physical level and not the system (e.g., policy) l…[Read more]

  • Occurrence is related to the specific cause (#1, tool breaking), since the undersize diameter could be caused by more than one cause, and each is addressed separately.

  • For mechanically oriented applications I believe Shanin is simpler and highly effective.