Joel Splosky posted an article discussing the tension between software development team efficiency and ability to respond opportunistically. The story he tells in “From the ‘you call this agile?’ department” is how interrupting a developer for 2 hours to work on an emergency sales-related task can delay their overall primary by anywhere from a day to a week. Task switching imposes a significant cost on productivity–knowledge work has a startup cost and achieving flow is difficult. So, why interrupt? As Joel points out, the net cost to the company of the reduced productivity might be offset be the extremely high value of the two-hours of work. He suggests that Agile development methodologies are designed to minimize the costs of just this sort of situation.
I’ve written about it before, but Tom DeMarco’s book Slack addresses this very issue. According to DeMarco, these sorts of interruptions are part of business. He likes Agile methodologies, but his solution is more straightforward: make sure your teams has enough Slack, the free time to do unscheduled and unplanned work.
