Original Date: 09/15/2003
Revision Date: 01/18/2007
Best Practice : Component Lean Implementation
Lean Manufacturing initiatives at United Defense, L.P. Ground Systems Division Aiken has allowed the company to realize significant savings in material, time, cost, inventory, and work in process, and ensured continued competitive advantage for many of its products.
In 1996, United Defense, L.P. Ground Systems Division (UDLP GSD) Aiken began machining gun shields for one of the U.S. Navy’s large gun programs. The gun shields consist of outer plates and inner skins. The outer plates are approximately three inches thick and of various complexities in shapes. The inner skins are generally thinner than the outer plates, and consist of several flat plates machined to different contours and sizes.
Originally, large plates of material were ordered and transported to a saw where the plates were cut into large, individual blanks of material. The many different pieces required to build a complete gun shield were machined on different machines. While effective, this process of manufacturing the different pieces required for one gun shield assembly created numerous opportunities for improvement. As the first step in implementing a Lean Manufacturing philosophy to the manufacture of gun shields, a nesting program was developed. The nesting program minimizes material usage, allows the use of smaller blanks of material, and allows material vendors to hold raw material to a tighter flatness tolerance with smaller plates. This process improvement allowed UDLP GSD Aiken to eliminate 17 set-up and run operations on its sawing operations.
Further Lean initiatives included value stream mapping of various parts required for a gun shield set, moving incoming materials to the “point of use,” machining only the parts needed for one set instead of machining a complete order of individual parts at one time, eliminating hold down fixturing by moving the machining to machine tools that have vacuum clamping capabilities, and moving the packaging of the completed sets of parts to the machine where the parts are manufactured. The Lean Manufacturing initiatives taken on this one product line demonstrated dramatic results in saving time and money for the company. An example of this saving is demonstrated with the outer plates, where part travel distance has been reduced by 75%, floor space requirements reduced from 428 square feet to 81 square feet, and machining operations reduced by 72%. Similar savings were generated on the manufacture of the inner skins.
UDLP GSD Aiken demonstrated and realized the many benefits of a strong Lean Manufacturing philosophy. These initiatives allowed the facility to reduce scrap and rework and process cycle time from receipt of order to final payment, remove wasteful tasks/processes, reduce inventory and work in process, provide quicker customer response times, and add value for the customer.
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