Why do some professors have less than 8 service credits?

In the 2017 collective agreement, there was a change introduced as to how the service credits are calculated. These changes are that from October 1, 2017, the credits are earned on the basis of one month credit for each calendar month in which the employee teaches 30 hours or more as a partial load teacher. If you have questions about how service credits are calculated, please speak with your Associate Dean.

Given that prior to October 1, 2017, service credits were earned based on .5 per month in which the employee taught 30 hours or more, there are differences in service credit levels depending on when they were earned.