Original Date: 07/21/2003
Revision Date: 01/18/2007

Electric Boat Corporation, Quonset Point Facility’s Build Sequence Work Package is a documented approach for capturing the optimum sequence to manufacture a highly complex assembly using an Electronic Product Model and associated three-dimensional views to develop a detailed assembly sequence at the part level, taking into account the maximum amount of subassembly, maximum welding mechanization, maximum utilization of automated layout marking, and minimum material handling.

Electric Boat Corporation, Quonset Point Facility’s (EBQP’s) latest advances in manufacturing technology are embodied in its Build Sequence Work Package (BSWP). BSWP is a documented approach for capturing the optimum sequence to manufacture a highly complex assembly utilizing the Electronic Product Model. EBQP personnel use this model and associated three-dimensional views to develop a detailed assembly sequence at the part level, taking into account the maximum amount of subassembly, maximum welding mechanization, maximum utilization of automated layout marking, and minimum material handling.

Building a highly complex assembly such as a submarine that contains thousands of subassemblies, parts, and operations is a challenging task. The traditional approach employed the use of hard-copy drawings and data as the primary vehicle to provide technical requirements and trade instructions to the mechanics on the deck plates. Drawings were difficult to read and interpret, and often required several drawings to obtain the full scope of work. Accessing drawings, work instructions, technical data, and other relevant information was time consuming and required access to multiple drawings and frequent use of a database containing pertinent information. EBQP discovered that some of its new personnel did not have the background to quickly adapt. Because of EBQP’s Advanced Manufacturing Technology program, the traditional approach was questioned. The company realized it needed to provide trade supervision and mechanics with an improved tool to aid in the understanding of the scope of work represented by the drawings, and customize manufacturing aids that enable a mechanic to spend minimum time understanding the drawing and technical requirements. Mechanics were spending about 15% of their time following the traditional process and not adding value to the product. EBQP recognized the need for a single, comprehensive, user-friendly manufacturing aid that would provide all information to the trades needed to complete a given unit.

In response to that need, EBQP is in the process of providing manufacturing aids in the form of isometric views that will present the technical requirements, work sequence, trade instructions, and accurate control requirements in a clear and concise manner. Technical requirements are pulled down from CATIA design models to include part numbers, isometric views, drawing details, critical dimensions, and applicable notes. The work sequence depicts the order of structural assembly, scope of subassemblies, sequence numbers, and exploded views when required. Trade instructions include critical dimensions, fixture requirements, joint design and identities, length of welds, and key views. The entire process is accomplished by a multi-discipline team that includes representatives from Operations, Process Engineering, Accuracy Control, and Planning and Production Control. The result of these efforts is the consolidation of all manufacturing documents and requirements into a single, user-friendly BSWP that provides complete, detailed instructions and pictorial sequences for the step-by-step fabrication of the unit.

When fully implemented, the BSWP will significantly reduce the complexity of interpreting drawing and technical requirements, while providing pre-planned manufacturing sequences. The process will eliminate the need for multiple drawings, and is anticipated to eliminate 15% non-value-added work per tradesman.

For more information see the Point of Contact for this survey.