Context switching

We can “generate” available thrust, and up the angle of the projected line, by minimizing the amount of context switching. Context switching is caused by constant interruptions and fragmentation of the work in progress when working on too many things simultaneously, even if all of them contribute to the software solution. By reducing context switching, and providing an environment where programmers can zone in on their work for longer periods, we can increase the available thrust compared to an environment where these factors are not in consideration. Measuring how much effective time we gain by minimizing context switching is not very difficult. The nonscientific way to do it is to ask a developer about how much time a day they feel is being lost from interruptions, or to add 5–15 minutes for each interruption and get an average number of interruptions. Since context switching can easily contribute to 30–50% effective time loss (you read this correctly), it is imperative for a scrum master or project manager to familiarize themselves intimately with ways to minimize it: 

• Keeping an open and functioning communication network within the team (communication does not equal chatter) 
• Ensuring people are available for feedback when needed
• Guarding the team from undesired external communications (when someone, a manager maybe, comes with a random and unrelated request)
• Scheduling meetings according to how developers work
• Identifying queues, applying WIP limits (work in progress limits), and facilitating short cycle times
• Having stories clearly specified
• Promoting direct interaction, communication, and collaboration between all team members (improving sociometrics)

These are all examples of things we can do to minimize context switching for the team. The time loss is not the only negative that comes with context switching. Sometimes brilliant ideas will disappear or never appear because the creative context was not preserved for long enough. These are losses that are difficult to measure, but not so difficult to feel.