The cost of context switching
We joined a new client few weeks ago. We were told to improve things slowly as the teams were performing pretty well for the last months. We accepted the challenge as we saw a lot of things were implemented well but we just changed one thing. We asked the teams members of the different teams to be aware of context switching. The result is an increase of 20% of the velocity in just few sprints.
Scientific have demonstrated with fMRIs that individuals cannot more than one task at the same time. Only impulses in each different hemisphere of the brain may happen at the same time. Studies demonstrate that IQ test results vary with and without interferences (phone calls, emails, etc) for the same people. The results decrease in 10 points when people are interrupted while performing the test in comparison to performing the test without interruptions.
On the other hand, if we try to analyse how computers multitasks, they execute the tasks one after the other but very fast. Soo fast that we have the perception things happen in parallel. For example, different softwares running at the same time, etc. The true is computers can do small operations for each of the softwares we have opened very fast but humans cannot do the same. If we try to switch from one small tasks to another, there is a cost intrinsic in move between then. For medium or complicate tasks this cost is even higher. As a consequence, we cannot do the same than computers. We need to focus in tasks for a some time. Specially when we are performing complicate tasks, we need some time to really get the understanding and context to get the job done properly.
Collaboration between team members is fundamental. We all know that. It is one of the fundamentals of Agile. So, how can we balance the reduction of context switching with the necessary collaboration between team members? This is something that may vary between teams and companies. Something which is really working in our client is the use of messaging apps like Slack, HipChap, Campfire or any of the others. These tools allow team members to ask for anything they need from their peers whose may have a look to requests on real time or later depending of their load at the moment. We encourage team members to unblock their peers as soon as possible explained in this article from Airbnb.
Most of the companies love to work in several projects at the same time. Everyone believe that of all the projects are important, we need to demonstrate progress in all of the at the same time. The reality of this is that, as demonstrated by thousands of the projects studied by Yale University, the projects ends up delivering almost twice later than if they were prioritised and serialised reducing context switching of the teams. More about this in our category priorities.
We found really interesting the experiment by Harvard Business Review that prove the statements above at The Multitasking Paradox.