I am often asked whether model-based definition (MBD) could become a reality and, if so, when that would be. Actually, the practical MBD journey at Gulfstream that started 13 years ago can answer these questions better than anyone or any arguments. It is a reality already today at many manufacturers such as Gulfstream—and they are enjoying huge successes. In this article, let’s take a closer look.
A subsidiary of General Dynamics, Gulfstream designs, develops, manufactures, markets and services business jet aircraft such as the Gulfstream G650 model shown in Figure 1. Gulfstream employs more than 13,000 employees and has produced more than 2,000 aircraft since 1958. The Gulfstream product line consists of the G280, G450, G550, G500, G600, G650 and G650ER as shown in Figure 2.
Figure 1. The Gulfstream G650 model. (Image courtesy of Gulfstream.)
Figure 2. The Gulfstream product line. (Image courtesy of Gulfstream.)
Thanks to the implementation of MBD since 2003, Gulfstream achieved a series of remarkable successes. For example, it was the first to realize a long-held aerospace industry dream, an aircraft developed with a Federal Aviation Administration (FAA)-certified, fully electronic MBD system. It designed the G650 model shown in Figure 1 completely with the MBD approach in 2007. Later, G650 MBD data was heavily reused in the G500 and G600 models shown in Figure 2, so that Gulfstream was able to concurrently design these two new models and announce its test flights together in early 2015.
Between the 2D drawing approach for the G550 model and the MBD approach for the G650 model, the standard parts and part numbers were reduced by more than 50 percent. Even more amazingly, the number of outfitting clips, angles and brackets were reduced from around 450 down to only 6. The reduction of part numbers alone generated huge savings in the supply chain management. At the barrel joining step shown in Figure 3, the assembly time was cut from three and a half days to only 15 minutes.
Figure 3. The barrel joining assembly time was reduced from three and one-half days to only 15 minutes. (Image courtesy of Gulfstream.)
Although such successes are the envy of the manufacturing industry, the MBD journey at Gulfstream is not necessarily unrepeatable for others. At the very least, there should be plenty of constructive lessons and recommended practices to learn from it. To begin with, let’s review the history of Gulfstream’s MBD implementation.
Gulfstream first started an MBD project with the G450 model back in 2003. The initial driver was quite simple. The old approach to outfitting an aircraft was low-volume, high-customization and hand-built. It relied solely on highly skilled craftspeople to interpret 2D engineering drawings with limited content. However, as sales increased, a significant change to the business model and process was needed to support higher-volume production.
Although the implementation team had a long-term goal of designing an entire aircraft with the MBD approach, to address the most urgent bottleneck—lower the complexity and control the risk—it focused the first attempt on the aircraft completion step, which was mainly about the interior design as shown in Figures 4 and 5. As a stepping stone, focusing on the completion enabled the team to minimize the risk because the interior design isn’t mission critical to an aircraft after all. The team also avoided the complexities of managing machined parts from many external suppliers and dealing with multiple sophisticated business systems along with remote infrastructures. Another consideration was to test the potential of saving standard part numbers because there were a large variety of standard components at the completion step that produced a heavy procurement overhead.
Figure 4. A Gulfstream jet interior design. (Image courtesy of Gulfstream.)
Figure 5. A Gulfstream jet forward fuselage system. (Image courtesy of Gulfstream.)
To provide a true 3D electronic representation of the aircraft, the engineering team modeled everything, including fasteners, veneer, hoses and so on, as the nominal geometries using CATIA V5. The 3D digital models allowed the team to increase the part reuse during the design phase, minimize technician’s subjective customization on the shop floor and ultimately reduce part numbers by more than 50 percent. Nowadays, the model-based interior design has been expanded to the entire airplane fleet.
In 2007, building upon the MBD successes of G450, Gulfstream started designing and manufacturing its flagship product, the G650 model, entirely with the MBD approach, including the airframing, integration and completion procedures. That was a huge change and added a great deal of complexity to the production processes, engineering systems and business systems. Gulfstream built new plants and factories that were completely based on the MBD process. There were no 2D drawings or 3D dimensions because the 3D models conveyed the dimensions already. Users were equipped with the software tools so that they could interrogate models for relevant dimensional information as needed. Designers only called out annotations for exceptions and critical characteristics. Other key attributes, such as tolerance standards, materials and surface finish processes, were stored in the product data management (PDM) system. Assemblies were defined by PDM structure links. The MBD approach was deployed to all users across the enterprise such as engineering, manufacturing, assembly, quality, purchasing, product support and the supply base.
As a result, Gulfstream was able to reuse the G650 model design data throughout the entire production process. For example, as shown in Figure 3, with the barrel joining assembly step, it used to take five people three and one-half days to make all the components aligned and smooth at an airplane quality level. Now, due to the accurate digital models, it only takes 15 minutes. According to Jeff Kreide, the production capacity was only able to outfit 12–15 airplanes per year. After years of the MBD progress, Gulfstream could run nearly 40 airplanes per year in 2013, which supported well the growing sales volume as mentioned above.
Furthermore, the reuse happens not only across one product line, but also in the later G500 and G600 models. Gulfstream was able to concurrently design these two models by reusing the G650 MBD data. In early 2015, both G500 and G600 models were announced in flight tests. The similar reuse benefited the latest G650ER model too. Even based simply by the appearance of the top four aircraft listed in Figure 2, they look very similar to one another.
That’s it for now about the MBD history and successes at Gulfstream. I hope it can help you and your organization build up interest and confidence. To learn more about how SOLIDWORKS MBD can help you with your MBD implementations, please visit its product page.
About the Author
Oboe Wu is a SOLIDWORKS MBD product manager with 20 years of experience in engineering and software. He is an advocate of model-based enterprise and smart manufacturing.