Original Date: 10/20/1997
Revision Date: 01/18/2007
Information : Build-to/Buy-to Packages
As part of its Product Definition Team and Delivery effort, Northrop Grumman uses build-to/buy-to packages as an on-line, integrated data management system to maintain complete data for buying, manufacturing, and defining its product parts. This approach promotes engineering as the nucleus for any design changes and encourages communication with all affected areas.
The FA-18 E/F program contains approximately 20,000 part number build-to packages. Each part number consists of a build-to/buy-to package that contains one or more drawings defining the particular part number. Each build- to/buy-to package is made up of the following documents:
a 3-D/2-D Unigraphics electronic drawing database Integrated Product Definition (IPD) data sheets
Assembly Line Operation Orders (ALOOs)
Product Release Documents (PRDs)
Engineering-change Orders (EOs)
The Unigraphics electronic drawing database is used by internal and external suppliers for part and tool development. In cases where external suppliers cannot use the Unigraphics format, Northrop Grumman delivers the CAD data in an Initial Graphics Exchange Specification format. Since Northrop Grumman now produces only in- house composite material, all other parts and tools must be purchased with a design database which fully incorporates all aspects of production to maintain the delivery schedule.
Northrop Grumman uses IPD data sheets to place all pertinent data (e.g., manufacturing, purchasing, tooling) in one document. These data sheets represent top-assembly; subassembly; and piece part information as well as conventional 2-D drawing data; datums; assembly joint types and gaps; assembly sequences; tooling required with detailed views of all jigs and master tools; and key characteristics. Although they are not used on the assembly floor, IPD data sheets remain a valuable engineering tool.
ALOOs are generated from IPD data sheets for a particular Process Cost Center. Used on the assembly floor, ALOOs identify reference drawings; required parts and documentation; certification and qualification requirements; manufacturing notes; work instructions; inspection items; tool kits; and miscellaneous caution statements. These documents tie together all requirements for completing a process in a particular Cost Center. In addition, tooling; work instructions; and parts and tooling kits are developed from ALOOs.
PRDs are used to communicate design changes that affect line issues to downstream users (e.g., planning engineers, manufacturing engineers) while EOs define these design changes. Both PRDs and EOs are scanned into the system to provide on-line access to all affected users.
Northrop Grumman implemented its on-line, integrated data management system approximately five years ago during the F/A-18 E/F Engineering and Manufacturing Development program. Since that time, the company has transitioned its build-to/buy-to packages into the FA-18 C/D program.
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