One of the 12 Agile principles that we should all be holding in high regard states …

Agile processes promote sustainable development. The sponsors, developers, and users should be able to maintain a constant pace indefinitely.

The team is accountable to their sustainable pace.

Sustainable pace should be on all of our minds on Sprint Planning day.  The Product Owner brings forth 20 stories and the team negotiates them down to 15 with sustainable pace and their velocity range in mind.  For those teams that handle production support, we all know it can be the wild card.  During the planning session, we mitigate this risk by having team members predict their personal sprint capacity (50%, 80%, etc.), taking into account non-sprint meetings and a predictive measure of support.  Also, we can further manage this by only working on support that our Product Owner deems immediate work.  Any other support can be backlogged and planned into a future sprint. Now, should all hell break loose in the support arena, some stories may be dropped or some stories might not meet the team’s definition of done.  No one should take it personally.  No one should feel like they are disappointing their Product Owner or their ScrumMaster.  Besides, there’s always the next sprint!  Story points and velocity are just numbers.  They are not used to grade a team, but rather intended help a team plan.  These sorts of discussions around the sprint goals and support should be had each and every day with the team, the Product Owner, and the ScrumMaster as part of the daily Scrum.

Bob Hartman provides a balanced take on sustainable pace:

http://www.agileforall.com/2009/07/24/new-to-agile-work-at-a-sustainable-pace/

The person is accountable to their work/life balance.

So now, a bit about work/life balance … Your ScrumMaster and functional manager don’t necessarily know if you are pulling ridiculous hours to pull off a story.  If you’re at home working off hours, we can’t easily observe that.  If you send me an email at 8pm a night, I don’t know if you just had a quick thought or if you have negatively impacted your work/life balance.  We all need to speak up on this topic and engage in constant dialogue with management.  The occasional sacrifice is appreciated, but shouldn’t be considered your team’s sustainable pace.  In fact, by working continuous overtime and not making it highly visible to your team, Product Owner, and ScrumMaster, you risk upping your team’s velocity, which just sets unrealistic expectations.  That said, work/life balance is a personal thing.  There are many happy “workaholics” in the world (I might just be one of them).  My threshold is different than your threshold which is different than the guy next to you.  We are all personally accountable to our own work/life balance!