A sustainable pace is the rate of development that the team can maintain consistently without burning out team members.

This idea of a sustainable pace is one of the central drivers behind XP (eXtreme Programming) . Any development team can hack out gobs of code over a one-year period, but sustaining code much beyond this period is a costly and difficult proposition.

XP suggests that activities should be built into the everyday work, rather than bunched up and performed only at particular points during the development cycle.  For instance, inspect the code all the time through pair programming and collective code ownership, and continually specify the system through automated tests all the time.  This prevents roadblocks in the process from occurring that prevent maintaining a sustainable pace throughout the entire development cycle.

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