As per the Pay Equity legislation, if employees do not have the same compensation structure then they are different job classes.   That being said, they are some scenarios where they may be the same job class if the employee has the understanding and there is a formal organizational policy that new employees start on a temporary/hourly basis and achieved salary/permananet basis through specific work milestones.  If you have questions whether or not 2 employees are in the same Job Class, please contact an HCI consultant or legal representation.