Speak to your AD team, ask them to set the account to not allow interactive logins (users should not be using the service account) and ask them if they can put any alerts or notifications to let them or you know if the account does become locked. If it does, you should investigate who or what is entering a bad password and resolve the source of the problem.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability