An article in Manufacturing Engineering (“Picking a Marvel at Deere,” January 1989, pp. 74–77) describes how the John Deere Company uses SPC methods to help choose production equipment. When a machine...

An article in Manufacturing Engineering (“Picking a Marvel at Deere,” January 1989, pp. 74–77) describes how the John Deere Company uses SPC methods to help choose production equipment. When a machine tool is purchased, it must go through the company capability demonstration prior to shipment to demonstrate that the tool has the ability to meet or exceed the established performance criteria. The procedure was applied to a programmable controlled band saw. The band- saw supplier cut 45 pieces that were analyzed using and R charts to demonstrate statistical control and to provide the basis for process capability analysis. The saw proved capable, and the supplier learned many useful things about the performance of his equipment. Control and capability tests such as this one are a basic part of the equipment selection and acquisition process in many companies.