The Cost of long Build Times

The cost of slow builds

Let’s say you have 50 developers working in your company. Let’s also assume that the average time for a build is 10 minutes. If 10 builds are started per day per developer, we are at a build time of 100 minutes per developer, which means 83 hours of unproductive waiting time for the entire team – every day.

With an average developer salary of 50,600 Euros per year (average Vienna according to Stepstone), a 10-minute build costs ~1,807 € per day. Calculated over 5 days, that’s a cost of € 9,033.33 or € 469,820 over the year (with 260 working days).

Let’s make it simple and assume you can reduce the build time by 5 minutes. The saving: 4,517 € for 5 days or 234,867 € per year! 234,867 €, which is now being used productively.

Let’s consider this in working days: Your company, your department, your 50 developers get back 10,833 hours of waiting time per year – that’s five and a half working days per developer!

Of course, one could argue that this waiting time is not lost. A developer can do something else in the meantime. But multitasking has something to say about this. And multitasking also causes costs.

According to a study by the University of California, it takes about 23 minutes to resume a previous task with full focus. This means, if a new task is started during the waiting time, the costs actually increase because developers need more time to get back to the old task. The costs of a long build time are actually even higher and the reduction has an even stronger effect than shown here. The shorter the interruption, the better.