Despatch Schedule Addon

Requirement is Sales Department executive should plan based on the available inventory. For example Customer A, B, C placed the sales order for an item X on the same date . In this Sales Department has to take the decision based on the customer history( it places the main role) when it has to dispatch ,how much qty should dispatch , to which customer ( based on the balance history) , what about the route of each customer . These information should give to Sales manager for approval . Then the sales manager approval then only sales executive will start the dispatch process.

Please let me know any functionality is available in Navision?