In the previous article I talked about using the Mean to help you determine initial KPI targets. There is an old saying in statistics that goes like this:

 “A man had one foot in a bucket of ice water and another foot in a bucket of boiling water and he said that on the average he felt just fine!”   

So when we look at actual KPI data (for example turnaround times) it is not only useful to know the Mean   but also the “spread” or standard deviation.  One very simple and visual example to illustrate this concept comes from target shooting. In target number “1” we see that there is no consistency. The marksman could not control his or her breathing, probably jerked the trigger and probably was watching something other than the front sight. In other words, the marksman was lacking a solid procedure and the skill to follow that procedure. Now suppose he or she got some mentoring from one of the experts on their team. After a week of receiving some coaching and practice their results now look like target number “2”.  Even though none of the shots are in the bulls-eye, this set of holes (or for our analogy, turnaround times, etc.) is much, much better!  Why?  Because they are consistent and predictable! Since consistency is a prerequisite to great service, we have measurably improved the performance. Next: how do we get the results in target number 3?  With a pistol, the group can be moved into the bulls-eye area by adjusting the windage and elevation on the rear sight. If we have a service team all hitting metrics consistently as in target number two, then we can either move the bulls-eye (declare a new target value) or improve a procedure that the team uses. So we can move the target to where the team is, or improve the team to meet the target.  Use the data you have and look at the variability around your service. You can use standard deviation to measure and discuss this spread. Tip: An Excel spreadsheet formula to calculate the standard deviation in cells B1 through B9 would look like this: “=STDEV(B1:B9)”.  Once you know this spread, you can take action if necessary and “tighten up the spread”  through training and improved procedures. This will help you measure, and therefore position you to improve, the consistency of your service.

This entry was posted on Saturday, November 17th, 2007 at 9:52 pm and is filed under Service Tools, Service Tips, Measuring Service, Accountability in Service. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.