Original Date: 04/28/1995
Revision Date: 01/18/2007
Best Practice : Key Characteristics and Variability Reduction
Lockheed Martin Electronics and Missiles (E&M) has adopted an approach called Key Characteristics and Variability Reduction to its quoting, design, and manufacturing processes (MPs) as part of the company’s continuous improvement efforts. This approach has enabled Lockheed Martin to translate critical customer requirements into detailed specifications, facilitating separating “critical few” from “trivial many” product features.
Lockheed Martin used to follow the classical approach of defining the system requirements, conducting a trade-off analysis, assigning component requirements, and detailing the resultant specifications. This did not support the company focusing efforts on the few critical attributes, while allowing standard practice to accommodate the non- essentials of the design.
Acknowledging that it would be extremely difficult to conduct Variability Reduction techniques on all the variables of all the products/processes involved, Lockheed Martin identified the relatively few high-level critical features of any design. Each of these features, in turn, could have many crucial components which contribute to the overall criticality, but the analysis greatly reduced the field of consideration.
Once identified, variability reduction and the resulting statistical tracking is applied to those critical features. Process capability studies are conducted and a trade-off analysis made to determine which machines/processes can achieve the required key characteristics.
One result of using this methodology was the invention of a variability reduction flag being incorporated into Lockheed Martin's drawing packages and procurement documentation. This flag indicates to both subcontractors and their own shop floors which geometric features are absolute must-haves and which features they can apply the knowledge of their trade to modify for ease of manufacture. This effort provides a substantial benefit to the design process by allowing the original equipment manufacturer to provide input up front, as well as greatly reducing the habitual Engineering Change Proposals that follow any new design.
Lockheed Martin is currently filtering this approach, along with the Design for Manufacture/Assembly (DFMA) methodology, down into its vendor base, thereby demonstrating the commitment to continuous improvement.
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