Decision support system for purchasing management of large projects

The Decision Support System (DSS) may be used under two scenarios. Under the first scenario, we have a project to execute, and we are looking for a good way to manage the purchasing to minimize the expected costs. The decisions under our control are when and from whom to order each item. Under the other scenario, we are bidding for the project, and wish to assess the cost associated with the purchasing decisions which we should consider before making our bid. In both cases we take into account expected out of pocket costs as well as lateness and/or expediting penalties. The DSS is designed to help choose the best supplier for each item and schedule the placement of the orders - decisions which are very difficult to make well without such a model based DSS.