Original Date: 05/08/1995
Revision Date: 01/18/2007
Information : Variability Reduction
A major element contributing to the cost of manufacture is the failure to understand and design for variation in component parts. McDonnell Douglas Aerospace (MDA)-St. Louis has addressed this problem through the use of Integrated Product Definition (IPD) data sheets which query the way a part is dimensioned and toleranced in relation to its functional use in a component. An MDA IPD team comprised of personnel from design, production, and assembly check parts for tooling requirements to ensure specified tolerances are realistic and not beyond the capabilities of manufacturing processes.
Two tools used in this variability reduction effort are geometric dimensioning and tolerancing (GD&T), and design for assembly. GD&T is a drawing language that communicates a part's functional requirements, defines common datums, controls tooling and assembly interfaces, and provides uniform international interpretation. Elimination of excessive tolerances results in better product performance and reduced cost of assembly. Design for assembly focuses on part count reduction by eliminating unnecessary parts and combining others into one. The application of these methods has reduced the number of parts on the F/A-18 E/F by 33% over the previous C/D model.
For more information see the
Point of Contact for this survey.