You're evaluating the job, not the individual. If I am a casual or a part-time worker in one department, it's the job that's being evaluated. If I move to a different kind of job in another position part time—it would be better if I didn't have to have three part-time jobs—but pay equity is not about the individual, it's about the job.
On April 18th, 2016. See this statement in context.