Blame the system

American statistician W. Edwards Deming defined two origins of variation in a process or system. Common cause of variation is the noise in the system, constantly occurring and predictable by a measure of probability. Special cause of variation is one that is novel and unpredictable, one that is always a surprise – this is the signal in the system.

Deming wasn’t the first person to distinguish between the two – credit should also be given to his contemporary Walter Shewhart – but he’s as good an introduction to the concept as any.

In questions of management and organisation, it’s vital to distinguish between the two. Treating common causes, i.e. those arising in the system, as if they were due to individuals in your work force not only gives you no insight into the function of the system, but also runs the risk of demoralising your team. The tendency to do this is particulaly prevalent because experiments by Deming have shown that this type of variation is not evenly distributed among workers, because the system affects people in different ways. The fact that a member of your sales team sells on the lower end of a given range compared to a colleague is in as much as 94% of cases (Deming’s approximation) the product of the system.

Want to change the system? You can’t do it by forcing your workforce to work harder. This only breeds resentment. It is the responsibility of management to see how behaviour is affected by the system, and consider how the system can be changed to improve outcomes.

For more information on Deming’s ideas, try starting with this video on burnt toast. Never stop learning!

Maths nightmares

I only have one nightmare theme these days.

I’m almost always back in Llandrillo College, before I went to university. It goes one of two ways: I suddenly remember a maths class I’m supposed to have taken, or I find myself sitting in a maths exam I’ve not prepared for. I’m overcome with absolute dread as I struggle to think how I ended up at this pathetic state of ignorance.

Then I wake up. The exam isn’t real, but the dread of my relative innumeracy is very real.

It’s not like I absolutely can’t do maths. Couldn’t pass a proper maths A level though, let alone the IB Higher Maths exam. I got lost somewhere between algebra and calculus.

I’ve tried Khan Academy before, but at the time it had no way of estimating your ability of big chunks of the math curriculum, and going through all the really elementary stuff was way too time consuming. Now I’m pleased to see they have a pretest which immediately skips the stuff you know well enough to progress.

It’s been a few months since my last nightmare. My old maths teacher Tony Thomas made a cameo appearance, handing me a dismal failing grade on a practice paper just like he did in 2007. Except he wasn’t in a pub kitchen at the time like the dream.

Now I’m studying something a little more in the realm of the computer scientists and economists, perhaps there’s more incentive to get the maths up to speed. Will 2014 be the year I reclaim the love of maths I lost somewhere around the age of ten? We’ll see.