Eligible amount in the compensation plan

Summary

What is the best practice to store the yearly Dollar amount for incentive payment to be used in the compensation plan

Content

We have a compensation plan in which we use it for Incentive payment. We are using a DFF in the assignment page to store their yearly $ amount, and that value gets referenced in the compensation plan. i wanted to see if there is a better place or better practice for storing that $ amount vs a DFF in the assignment page.

This came about because we are building a promotion plan, and in that plan we want managers to edit that amount. it looks like i can't update that DFF using the promotion plan, so i wanted to see what are other users doing?