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Re-Engineering Aerospace Design PUBLIC ACCESS

By Integrating its CAD/CAM tools, Boeing's Space Systems Unit hopes to Enhance the Quality of its Products as it Reduces both Design and Manufacturing Cycle Times.

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Associate Editor

Mechanical Engineering 120(01), 70-72 (Jan 01, 1998) (2 pages) doi:10.1115/1.1998-JAN-5

This article reviews that by integrating its CAD/CAM tools, Boeing’s Space Systems Unit hopes to enhance the quality of its products as it reduces both design- and manufacturing-cycle times. Sharper market competition led management to re-emphasize the practice and couple it with integrated CAD/CAM systems to provide a more supportive environment for concurrent engineering, thereby assuring the customer that cost, schedule, and quality goals would be met. This concept, called integrated product development (IPD), was launched in 1991. Boeing’s intention is to use the IPD strategy to reduce design-cycle time and manufacturing-cycle time as well as recurring costs. To support IPD, the Boeing designers developed electronic change control (ECC), an online system that enables engineers, technicians, manufacturers, and logisticians throughout the company to track and control engineering changes on a network of minicomputers, workstations, and desktops. Among the Unigraphics-based tools Boeing uses in IPD is the electronic development fixture (EDF), a three-dimensional digital model. EDF enables its users to electronically investigate fit, form, function, and interference detection.

This article is the last in a series if articles based 011 Mechanical Engineering’s Industry Forum 011 Re-engineering the Product Development Process, held at the 1996 International Mechanical Engineering Congress and Exposition in Atlanta. Past articles are available on the World Wide Web at Mechanical Engineering Magazine On line, at www.memagazine.org.

As aerospace face the pressures of more-stringent customer requirements, shrinking defense budgets, company mergers, and the increased competition found in the global marketplace, they are being forced to re-engineer their design processes. The Huntington Beach, Calif., facility of Boeing CO.'s Space Systems Unit, for example, had long emphasized involving customers and suppliers with company engineers as early as possible during the design process to ensure that the company's requirements were met. Sharper market competition led management to re-emphasize the practice and couple it with integrated CAD/CAM systems to provide a more supportive enviro11lnent for concurrent engineering, thereby assuring the customer that cost, schedule, and quality goals would be met.

This concept, called integrated product development (lPD), was launched in 1991. Boeing's intention is to use the IPD strategy to reduce design-cycle time and manufacturing- cycle time as well as recurring costs. A key to this improvement is integrating the design tools themselves. "This involves defining your process and then selecting the appropriate tools to optimize their use," said Twila Hart-Humphrey, director of integrated product development at the Quality Systems & Services Unit of Boeing Space Systems.

"Simply benchmarking a lot of tools without understanding the process will not work. Design tools must be integrated to mesh together, not left to act in stand-alone fashion," she added. Since joining McDonnell Douglas in 1989-the original home of the Space Systems Unit, before the company merged with Boeing last August-she has worked on the International Space Station, the Delta Clipper spacecraft, and the C-17 aircraft; Hart-Humphrey is now focusing on Boeing's expendable launch systems.

According to Hart-Humphrey, the Huntington Beach group decided to use the Unigraphics CAD/CAM/CAE system from EDS Unigraphics in Maryland Heights, Mo., as a tool for design creation, design analysis, manufacturing planning, and communications between functions, thereby facilitating concurrent engineering and IPD companywide. This system continues to be used at Boeing Space Systems, although the IPD program can accommodate other software tools as well." It is easier to use a single product," Hart-Humphrey said.

The first step was setting up an advisory team to guide the integration of the Unigraphics design tool with the company's strategic plans. This was eased by the rapid development of computer hardware technology, according to Hart-Humphrey. In-house training prog rams were instituted to instruct engineering teams on how to use requisite Unigraphics modules to complete their projects.

For their part, process engineers at Huntington Beach standardized the Unigraphics design and manufacturing software, which is run on Hewlett-Packard work stations. They also adjusted the Macintosh desktop computers used on such projects as the International Space Station program to provide a shared window into the Unigraphics files stored on Digital Equipment Corp. V AX clusters.

To support IPD, the Boeing designers developed electronic change control (ECC), an online system that enables engineers, technicians, manufacturers, and logisticians throughout the company to track and control engineering changes on a network of minicomputers, workstations, and desktops. U sing ECC, designers can enter and review drawing changes, handle change rejections and comments, notify reviewers via e-mail, retrieve and display approval histories, search various types of data for comparisons, and set up charts and graphics to illustrate a point. Simple access to this system has been provided through Netscape Navigator.

Boeing engineers are using integrated product development to improve equipment such as this Delta 11 launch vehicle, which sent five commercial satellites into orbit from Vandenberg Air Force Base in November 1997.

A Boeing technician examines one of the second-stage structures that will be used on the Delta III expendable launch vehicle, a Delta 111 derivative scheduled for its first launch in mid-1998.

Grahic Jump LocationA Boeing technician examines one of the second-stage structures that will be used on the Delta III expendable launch vehicle, a Delta 111 derivative scheduled for its first launch in mid-1998.

Digitizing Design

Among the Unigraphics-based tools Boeing uses in IPD is the electronic development fixture (EDF), a three-dimensional digital model. EDF enables its users to electronically investigate fit, form, function, and interference detection. This makes EDF the primary tool for analysis, tool and support equipment design, wire-harness and fluid-tube development, and direct handoff to the CAM process. Tubing and wire-harness drawings are produced automatically from EDF centerline routing data. The database is also used to facilitate assembly instructions, illustrated assembly and maintenance aids, factory layout, and parts packaging. Parts manufacturing is automated by generating numerically controlled code from solid models that reside in the system.

Boeing engineers use their internal product data manager to approve or reject the EDF model. "This notifies everyone involved in a project at the same time, in any geographic location, so that when they retrieve the three-dimensional model to examine it, they will see the signatures and know where the data package is in the design cycle," Hart-Humphrey said. If a change needs to be made, it is done once in all the relevant places, she added. Boeing is receiving positive feedback on the Delta Launch Vehicle Program from the numerical-control programmers, who are able to tap in and use the single database model.

Once an EDF model is completed, Boeing engineers use variation simulation analysis (VSA) to confirm the accuracy of the specified tolerance and ensure that assemblies will fit together the first time. "We also verify the manufacturing procedure to double-check the assembly sequence, so that when we feed the data into VSA, we can be sure we are performing the right analysis with the correct tolerance," Hart Humphrey said.

The next step is an IPD certification performed by key designers, senior fellows, and other high-caliber Boeing technical experts. The certification team investigates the health of the IPD implementation on the programs. " IPD certification shows the different phases of the product's life cycle," Hart-Humphrey said, "and how applying integrated design tools to those phases can optimize production." She emphasized that "you realize substantial savings by the time that first vehicle comes off the assembly line and everything fits correctly, which is the goal of all our integrated- product-design tools."

This concept was demonstrated by the company's proposal for evolved expendable launch vehicles in 1996. "Certification showed the Air Force that we were doing a good job implementing IPD in designing the next generation of expendable launch vehicles," Hart-Humphrey said.

Managing the manufacturing process effectively is just as important to IPD as producing the optimum design, and it is accomplished through a process-based management system. As Hart-Humphrey explained, this involves charging a management team with defining critical process elements and prioritizing them to obtain a final assessment of process performance, "which yields benefits including a single process for continuous improvement, a consistent means to communicate status to product customers, and focused management attention on key customer-driven processes and priorities."

Boeing is evaluating common design systems for use in its IPD strategy. One common system Hart-Humphrey has personal experience with is the product data manager. This system was designed to facilitate access to important product information at the same time the movement of that information is controlled. Movement control prevents copying and thus unnecessary duplication. "Conversely, if you are trying to build and expand on a product, the product data manager enables you to go back to other design programs to capitalize upon previous work," Hart-Humphrey said.

The engineer cited the MD-XX program, which began in the summer of 1996, as a recent example of how IPD has sped up the design process. The MDXX was to have been McDonnell Douglas's next-generation airliner. Because the wing torque box was designed using linked parametric models, design changes did not require the difficult and time-consuming process of remodeling detailed parts. The MD-XX wing integrated product team was able to make three major changes on more than 400 parts and assemblies in 60 days, less than half the time it would have taken without IPD.

Hart-Humphrey noted that the next phase in implementing IPD at Boeing is devising a common approach for all of the aerospace giant's businesses. "Because Boeing is a virtual company-that is, highly computerized-we can utilize our skills across the corporation," she said, citing the Delta Launch Vehicle Project as a prime example of this "Design Anywhere, Build Anywhere" philosophy. To work on the Delta launch vehicles, Boeing has linked engineering teams based in Houston; Cape Canaveral, Fla.; Huntsville, Ala.; Downey, Calif.; Huntington Beach, Cali£.; Vandenberg Air Force Base, Cali£.; and Pueblo, Colo.

"The biggest challenge is getting the cultural changes we need to foster IPD-for example, by giving designers and manufacturers the proper training to support IPD," she said. " If we can persuade corporate leaders to do more thinking up-front in the design process than they are used to, we can design higher quality products that will get to market faster."

This mechanic inside the Delta 11 first-stage liquid-oxygen tank is drilling holes for tunnel clip brackets to support the electrical wiring for data transmission during launch.

Grahic Jump LocationThis mechanic inside the Delta 11 first-stage liquid-oxygen tank is drilling holes for tunnel clip brackets to support the electrical wiring for data transmission during launch.

Copyright © 1998 by ASME
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