Files open from Service Programs

["Guenther, Mike" <MGuenther@xxxxxxxxxxxxx>]

  Is there a significant performance hit from leaving files open that were 
opened by activated service programs in a job stream?
We have certain batch jobs that run specific service programs hundreds of 
times.  We don't explicitly close the files from these 
service programs anywhere in the job stream.  These open files stay open during 
the run of subsequent programs in the job stream.  Is this Bad?

Thank You,
Mike