Hello TW,
Probably the answers to your questions will vary a lot between small/big companies, different industries... country could also be a factor.
A1: Sales people alone cannot make such decisions, at best they can propose this as a strategy to keep a specific group of customers or increase sales volume on certain product group. This is more related to company strategy, planning and for sure people from Finance/Controlling also play an important role. I am just speculating here, because in the companies I worked in as a business user, we did not use SD rebate agreements.
A2: At least here I can provide a more reliable information - in the bigger operations there is an expert responsible for rebates handling (usually the same person is responsible for pricing - commercial department, but I have seen a case in a very small operation where they put in charge their billing expert, while the pricing user handled promotions planning as a second responsibility). So I think this depends on the resource availability in the company and the volume of data that should be processed.
A3: I can think of several possible reasons:
- The transaction for creating rebate agreements in ERP is not very user-friendly and if you have a lot of agreements to enter with multiple conditions it can take a while. Instead of entering data like a bot, the person can use the time for activities that add value.
- Excel is not just a lot faster for data entry, but most people in sales/finance are very advanced users, which don't need a lot of training or support for using it.
- Since excel is faster, if you have a lot of agreements to enter, you will not need to hire 5 people and pay salaries and SAP licenses.
- If rebates are handled in some non-SAP software, which can produce some files as a result, you can just upload them (I doubt that this is the case here, nobody in their right mind would use xls in this case, they would ask you about csv, dbf, xml instead).
Excel upload in SAP by key users can be a very unpleasant experience, I hope that your customer is planning to delegate that to central master data team.