Variation vs. Victory
Changing nappies taught me about variation. Here’s why.
“2 minutes and 31 seconds, sucker!”, I exclaimed as I finger-gunned my wife with one hand, whilst holding our baby with the other. “A full 10 seconds quicker than yesterday!”
“Not bad, but not great either”, remarked my wife.
“What do you mean?”, I asked defiantly.
“Well, yesterday you were 10 seconds slower than the previous day. The comparison doesn’t mean much. It was probably just a smaller poop today.”
“I assure you it was a category 5 Poo-nado”, I retorted.
“I’ll call it an improvement if and only if you maintain that record for a full week of nappy changes.”
As my ego crumbled, something in my head clicked.
In organisations it is easy to jump to big conclusions from just a few numbers. We may see one recent piece of work take more time to complete, and conclude teams are becoming lazy. We see another piece of work take less time, and conclude teams are improving. But neither of these conclusions are necessarily true.
As W. Edwards Deming reminds us, “life is variation, variation there will always be”. There will always be ups and downs - and about equal amounts of each. Any piece of work has an equal chance of being delivered earlier or later than average. We can therefore no longer simply compare the time it took to deliver one piece of work to the next, because “it will always be difficult to determine just how much of the difference [...] is due to variation in the numbers, and how much, if any, of the difference is due to real changes in the process” suggests Donald J. Wheeler.
So, everything varies. Comparing any two results offers little insight other than confirming variation exists.
But, if everything varies, how do we know if we’re improving?
When we introduce a process change, we expect it to positively impact all subsequent work. A real improvement in project delivery should bring all future projects closer to a shorter average delivery time.
So, real improvement requires a consistent change in results, not just a one-off.
The takeaway? Don’t be fooled by variation in the form of one fortuitous nappy. Zoom out - true improvement requires a consistent change in results over time.
