A customer called today confused about her data. She wanted to draw a control chart and thought the data might have a binomial or poisson distribution. She thought it was attribute data. She’d used the QI Macros Control Chart Wizard to create a control chart of her data and it chose an XmR chart. She wasn’t sure that was right. When I asked her what kind of data she had, she said, “write-offs”.
Write-offs are money, plain and simple. Money is variable (a.k.a. continuous or measured) data.
I explained that to her and suggested she stop worrying about what kind of distribution she has and just look at her data.
Continue Reading "Binomial, Poisson, Attribute, Continuous Data Control Chart Confusion"
In his speech Sunday at IHI, Don Berwick called for everyone to “recommit to improvement science” (step 5 in ERA 3 of healthcare transformation).
He sounded annoyed with the lack of use of Lean Six Sigma tools and methodologies.
I understand his frustration. I was there in 2006 when he asked everyone to “pledge allegiance to science and evidence.”
Over the years, I’ve done a stroke tally of the quality tools used in IHI poster presentations.
I gave each poster one checkmark for each type of tool used.
Sadly, even with all of the emphasis on control charts, Pareto charts and other tools of quality, they are used rarely in poster presentations.
Continue Reading "IHI 2015 Poster Use of Quality Tools"
Control Charts show your data as a line graph with average and sigma lines to determine stability. The average and sigma lines are calculated from your data. It’s easy to create a control chart in excel using the QI Macros. See http://www.youtube.com/watch?v=5TVKz4OQTp0
Continue Reading "Use Control Charts to Determine Process Stability"