To change anything, you must act.

There is nothing more destructive to team performance, trust, and credibility than committing to do something - the TALK - and then not doing it - the WALK. 

Unexpected things do come up.  There are times when you over commit.  But there are no excuses for not communicating and meeting commitments.  

The only acceptable options:

1) Negotiate a new date with the person you made the commitment to before it is too late to recover.

or

2) Ask for help from the team to meet the commitment when the date cannot be changed. 

Why would you tolerate anything less?

What would need to change in your organization to take walking the talk to the next level in your organization?