Just picked up a copy of Hubbard's How to Measure Anything - Finding the Value of "Intangibles" in Business. On a quick perusal (the number of unread books on my coffee table precludes anything more at present), the author makes a good case. Now, to apply it to quality control in janitorial service.
Over the years, I've seen a number of quality and management systems either designed for, or adapted to, what we do - Phoenix commercial cleaning service. They generally involve some sort of system of rating the job quality at a given time, to establish a baseline, and then some sort of commitment and methodology to improve, and to measure that improvement. Then, paste a gold star on your forehead (or not).
Problem is, the systems all seem to involve eyeballing portions of the job, and rating them. If there is no visible dust on baseboards, but perhaps a bit of grit felt by the inquiring finger, you define that as, say, a 90%. Add in window sills, and phone handsets, and restroom fixtures, and average the results.
Good, as far as it goes. But eyeballing surfaces for dust, and phone hand sets for grime or mascara, is a bit subjective. How do you differentiate a 90% from a 95%? How do you differentiate a good day on the part of the inspector from a bad? Or glasses that might need cleaning? Those measurements are the foundation of the system, and the foundation is built on shifting sand.
That's why, in our janitorial Phoenix operation, we measure indoor air quality. We use a simple, laser based airborne particle counter. Cost me as much as a used car, but it's a really neat toy. Central to our commercial cleaning Phoenix service is improving our clients' indoor air quality, removing spores, pollen, airborne bacteria and allergens - everything down to three tenths of a micron, using HEPA filtered vacuums, microfiber dust wipes and damp mops, and careful chemical selection.
National level studies of the above, and resultant indoor air quality readings, show a better than 50% reduction in daytime airborne particle count, in the size range of most allergens (half micron up to ten microns). If we are doing what we claim to be doing for our clients (assuming a fairly tightly sealed, multi-night per week schedule), those are the results we should show.
And, in general, we do.
So, using indoor air quality results of our service, compared to what the client had before us, as a good measure of our quality, I'm generating hard numbers as a foundation of our quality control system.