Skill, experience and years of service are the criteria the EBA discusses (oh, yes, and operational requirements). Qantas have produced a complex skills matrix with 7 different "weighted" bands, with about 20 different "skills" spread across the bands.
So far all of their efforts seem to have been concentrated on the skills matrix because nothing has emerged about the other criteria of experience or years of service. Hope the next two matrix aren't as complex as the first.