If you ever ventured in the direction of Lean in you software development journey you have probably heard about flow. If you read about Kanban and had a go at using it, you looked very carefully at how your work flows. You would have read perhaps that your work should flow well.
Flow is not a natural term we are necessarily used to though, unless we talk about water. In the early days it’s intuitive to equate flow and speed. It’s the easy conclusion to make when adopting our fluvial experience. So it often comes as a surprise that we are also advised to slow down in order to improve flow.
It certainly felt counter-intuitive when I first come across the idea. Even after having read more on the subject, while cognitively it became clearer, my intuition was still in denial. Until I could experience it first hand in reality.
Few years ago I used to drive from Newark to Nottingham. The journey was pretty straightforward, took about 45 minutes and run something like this: drive a single carriageway A46 for few miles, turn right at the Saxondale roundabout, through Radcliffe with a 40 mph limit and then a dual carriageway to the Nottingham ring road.
After a few years elsewhere, I found myself driving to Nottingham again. I was more worried this time though, as serious roadworks already begun to upgrade A46 to a dual carriageway and with them a 40 mph limit where you could previously drive 60 mph.
I fully expected for my journey to take longer. On the first day, I left home early to add some extra contingency and found myself arriving way too early. I thought I have simply avoided the morning peak. On day two similar thing happened. I started setting off slightly later and still arrived on time. I checked my timing, it turned out I was doing the journey in under 40 minutes.
How could this have been if there certainly weren’t fewer cars and I had to drive more slowly for most of my journey? It turned out a lower speed limit helped improve the flow. Remember the Saxondale roundabout and a limit on the road right after it? It was a bottleneck on that road. As cars now approached the bottleneck more slowly it didn’t clog up so much. The queues on the approach visibly shortened, reduced waiting time and thus my total journey time.
Today the A46 upgrade is almost completed. I no longer drive to Nottingham. The surprise, the experience and the realisation that slowing down really does help go faster is still here and has now become part of my intuition. I have seen it work in IT many times since.