Multiple Jobs being run at Work Center

We are running version 6.10.541 with Data Collection.
Our dilemma: We can log into multiple jobs during one Work Center 'session' ( let's say make (3) of part "X" , (1) each for Jobs 'a, b & c') it takes (1) hour total to finish all parts, then log out of the jobs.

However Vantage credits (1) hour for this part to each job, since we were logged-in for an hour on all three.
Other than logging-in and out of each job 3 or more times, does anyone know of a Work Center Set-Up, or other parameter that can be adjusted that would correctly allocate the actual time ? (in the example: 20 minutes to each job).