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Derek Benson

Statistics

Baby Steps With Quality Improvement

How a new parent calculates SleepPK

Published: Thursday, June 8, 2017 - 11:01

How early is too early to introduce quality into your everyday life? Have we missed out on improvement opportunities in our personal lives along our paths to achieving our career goals as quality professionals? These questions have me pondering how life could have been different for me growing up with a little more emphasis on data analysis for improvement.

A little knowledge of Walter A. Shewhart’s plan-do-study-act (PDSA) cycle could have been useful, for example, in helping the high school version of myself maximize test scores while minimizing the time spent agonizingly studying. Would I have spent less total time studying for that A+ grade had I reserved a small chunk of time every night reviewing notes instead of hours cramming at the last minute?

Even further back, perhaps the pre-teen version of myself would have been more understanding about my dad’s insistence on me keeping my room clean had I attended a seminar on quality hosted by the famous W. Edwards Deming. Deming’s eighth point on management reads, “Drive out fear, so that everyone may work effectively for the company.” If you had seen my room, you would have felt the fear that Dad was attempting to drive out!

It was around that age that I likely first watched Alice in Wonderland and was introduced to Lewis Carroll, who said, “Begin at the beginning... and go on till you come to the end: then stop.” Now that I’m a new father and possessor of the guilt of missed opportunities in my own life, what better advice than to start at the beginning?

I let my professional training kick in, collected data related to my son’s diaper consumption for six months, and am officially ready to answer the questions: Are babies predictable and, if so, am I capable of surviving this? Now, of course, we understand in all stretches of the imagination that this question is ludicrous. It didn’t take me six months to learn that! I decided to follow two processes—diaper consumption and sleep achieved—through the first six months of my son’s life because I was just curious if statistics would agree. (Or correlate?)

Thanks to SQCpack’s Six-Way Analysis, we’re presented with the following results for interpretation.

Daily diaper consumption

http://www.pqsystems.com/eline/2017/05/data_in_everyday_life_large2.png
Click here for larger version

I collected the number of diapers used per day and plotted the average weekly result over time. I also conceived that my bank account could survive anywhere between 0 (wishful thinking) and 10 diapers per day; these are my specifications (of course, I could have only used an upper specification). After identifying weeks one and two as special causes (there were so many I lost track), diaper consumption is pretty predictable according to the left side of the Six-Way Analysis. On any given day, I can reasonably expect that without some non-normal variation (let’s not go there), I would be changing, on average, 7.68 diapers per day. My capability summary, however, shows that the actual process variation is wider than my specifications. With a Cpk of 0.86, there’s room for improvement!

Thinking of changing diapers brings to mind a related topic: daily sleep patterns.

Daily sleep achieved

http://www.pqsystems.com/eline/2017/05/data_in_everyday_life_large.png
Click here for larger version

 

More specifically, how many zzz’s have Mom and Dad achieved? I’ve reasoned that a productive day at work should require 7 to 13 (dreaming again) hours of sleep the night before. It’s here where we see that statistics agree with common sense. The steep changes on our range chart on the left suggest there’s no telling what you’re going to get from night to night. Our Six-Way Analysis shows that it is reasonable to expect that optimal sleep will not be achieved consistently in the future. My “SleepPK,” as I’ve defined it, is extremely undesirable.

But there’s hope. We clearly see that better sleep is on the horizon. With better sleep comes higher energy. With higher energy comes more brilliant ways to apply quality improvement to everyday processes. Though babies are clearly not predictable, they are pretty fun!

Originally published May 5, 2017, on the PQ Systems blog.

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About The Author

Derek Benson’s picture

Derek Benson

Derek Benson is an application support manager for PQ Systems, developer of quality control software solutions. In his role as a member of the PQ Systems training team, Benson provides both on-site and remote assistance to customers around the globe. He brings a background of technical experience to his support role, and leads seminar and webinar training for new and practiced software customers. Recent consultancy clients include Amsted Rail, Timet, Grote Industries, and Continental Structural Plastics. Benson holds a bachelor’s degree in business from Ashford University.

 

Comments

Parenting SPC

A great start, now you can start designing how to analyze:

           - frequency (and intensity) of school fundraisers

           - cash flow variations for the latest <select an electronic device or article of clothing>

           - rate of hearing loss (yours) vs. age (child's)

           - blood pressure while teaching driving

           - how much you miss them when they move out