A final area that merits discussion is the use of MRP in a re-manufacturing environment. The use of MRP is widespread among re-manufacturers and three-fourths report using some form of MRP. A high percentage (86.2%) of firms report the MRP system is customized to some extent, and the uses of MRP vary greatly in this environment. Firms commonly use MRP for planning purchase and re-manufacturing order releases, maintaining bills of materials, and materials tracking. There was no evidence that firms using MRP systems were less likely to experience significant problems with purchase orders, inventory control, or due-date performance. Firms that incorporated MRRs into the purchase order release calculations were less likely to cite concern with poor visibility of requirements, but still cited visibility as problematic. This poor visibility is a function of the short planning lead times (average less than 4 weeks) and dependence on actual demand rather than forecasts. Few firms report being satisfied with their MRP systems, yet few report using alternative techniques.