Reference system to manage the general customer data

Each customer is automatically granted a payment index reflecting his payment behavior over a certain period of time. The payment experience is defined as the weighted average delay over the 6 last months. It is expressed in days. The payment index value should be
 100 corresponding to "good payment experience "
  200 for "bad payment experience"
  blank for "new customer" meaning good payment experience
A customer with no payments registered in teh last 6 months gets a bad payment index.

"Two aspects : 1/ customer who contact Solvay for the first time and then doesn't buy Solvay product 2/ regular customer for the GBU ""A"" who wants to buy a product sales bu GBU ""B"" . He is consider as a prospect by the GBU ""B"""