Two months into my first reward job and I have inherited the sales commission plan

I joined a packaging machinery manufacturer in Bologna in August as its first reward specialist, about 1,400 employees. I came from HR administration and expected to spend the first year on grading and the annual review.

Instead, the sales director retired, and the commission plan for 45 salespeople in four countries has come to me. It is a spreadsheet with eleven years of amendments. Three people have already told me their payment last quarter was wrong, and I cannot yet say whether they are right.

I am pleased to be here and would welcome advice on where a complete beginner starts with sales pay.