Navision Advanced Distribution or Navision AD, was a special release of Navision Financials 2.60 in 2000, containing advanced distribution and warehousing functionality. The functionality was originally developed by US partner Lanham Associates as a very successful add-on in the US. In the hand of Navision it initially became a failure. It was too slow and couldn't do what it was supposed to do. And it could not be integrated with Navision Manufacturing.
When Navision Attain was released in 2001 they where both merged into the main product. AD became the foundation of the advanced warehouse management functions still in NAV.