TL;DR: Using an upgraded (and fixed) Parallel Build Process Template allows to use multiple TFS2012 build agents simultaneously, which can be more than welcome when building metro apps that target all three supported platforms. A build that took 11 minutes can go down to 3.5 minutes.
Download the Parallel Build Process Template for TFS2012 here.
CI is a wonderful feature, especially when associated with Gated Checkins.
You’re certain that what’s in your source control is in line with your build definition and constraints, and that there is always a binary that respects a minimum set of rules. This does not ensure that your app is bug free, but still, that’s a minimum.
Build time matters
The downside of this validation is that there cannot be multiple builds running at the same time. This can become a bottleneck when multiple developers checkin within the duration of a single build run.
This means that the longer your build gets, the longer a developer might wait for its task completion because of a long build queue, and increase its task switching cost. If a build fails, the developer needs to unshelve its changes, make the necessary adjustments, then check-in again.
Below 4 minutes of build time, this stays in the acceptable range where the developer’s task context may not be lost if the build fails.