Our y-value sets the salary floor, so it's an effective tool for establishing a baseline. Depending on disciplines and areas of expertise, sometimes faculty members are hired at salary rates above the y-value. The y-value gives us a metric to decide, based on someone's education level and experience, where they fall in the grid, but it's not a perfect measurement. Would it resolve all the problems? Absolutely not.
A key component of what has achieved success here at Dal is not only having that y-value measure, but also revisiting the analysis in advance of bargaining or new collective agreements to give us an opportunity to temperature-check and know whether we're meeting the mark in terms of pay equity.
I don't think there's any system you could just implement and trust that it would take care of things forever. It's something you have to keep checking back on.