HPDC is used today, and can be expected to play a growing role in manufacturing, and more generally, engineering. For instance, the popular concept of agile manufacturing supposes the model where virtual corporations generate ``products-on-demand.'' The NII is used to link collaborating organizations. HPDC is needed to support instant design (or more accurately redesign or customization) and sophisticated visualization and virtual reality ``test drives'' for the customer. At the corporate infrastructure level, concurrent engineering involves integration of the different component disciplines---such as design, manufacturing, and product life cycle support---involved in engineering. These general ideas are tested severely when they are applied to the design and manufacturing of complex systems such as automobiles, aircraft, and space vehicles such as shuttles. Both the complexity of these products, and in some sense the maturity of their design, places special constraints and challenges on HPDC.
High-performance computing is important in all aspects of the design of a new aircraft. However, it is worth noting that less than 5% of the initial costs of the Boeing 777 aircraft were incurred in computational fluid dynamics (CFD) airflow simulations---the ``classic'' Grand Challenge in this field. On the other hand, over 50% of these sunk costs could be attributed to overall systems issues. Thus, it is useful but not sufficient to study parallel computing for large scale CFD. This is ``Amdahl's law for practical HPDC.'' If only 5% of a problem is parallelized, one can at best speed up and impact one's goals---affordability, time to market---by this small amount. HPDC, thus, must be fully integrated into the entire engineering enterprise to be effective. Very roughly, we can view the ratios of 5% to 50% as a measure of ratio of 1:10 of the relevance of parallel and distributed computing in this case.
The maturity of the field is illustrated by the design criterion used today. In the past, much effort has been spent on improving performance---more speed, range, altitude, size. These are still critical under extreme conditions, but basically these just form a given design framework that suffices to buy you a place at the table (on the short-list). Rather, the key design criteria is competitiveness, including time to market, and total affordability. Although the design phase is not itself a major cost item, decisions made at this stage lock in most of the full life cycle cost of an aircraft with perhaps 80% of total cost split roughly equally between maintenance and manufacturing. Thus, it certainly would be important to apply HPDC at the design phase to both shorten the design cycle (time to market) and lower the later ongoing costs of manufacturing and maintenance.
We take as an example the design of a future military aircraft---perhaps 10 years from now. This analysis is taken from a set of NASA sponsored activities centered on a study of ASOP---Affordable Systems Optimization Process. This involved an industrial team, including Rockwell International, Northrop Grumman, McDonnell Douglas, General Electric, and General Motors. ASOP is one of several possible approaches to multidisciplinary analysis and design (MAD) and the results of the study should be generally valid to these other MAD systems. The hypothetical aircraft design and construction project could involve six major companies and 20,000 smaller subcontractors. This impressive virtual corporation would be very geographically dispersed on both a national and probably international scale. This project could involve some 50 engineers at the first conceptual design phase. The later preliminary and detailed design stages could involve 200 and 2,000 engineers, respectively. The design would be fully electronic and demand major computing, information systems, and networking resources. For instance, some 10,000 separate programs would be involved in the design. These would range from a parallel CFD airflow simulation around the plane to an expert system to plan location of an inspection port to optimize maintainability. There is a corresponding wide range of computing platforms from PCs to MPPs and a range of languages from spreadsheets to high-performance Fortran. The integrated multidisciplinary optimization does not involve blindly linking all these programs together, but rather a large number of suboptimizations involving at one time a small cluster of these base programs. Here we see clearly, an essential role of HPDC to implement these set of geographically distributed optimizations. However, these clusters could well need linking of geographically separated compute and information systems. An aircraft is, of course, a very precise system, which must work essentially flawlessly. This requirement implies a very strict coordination and control of the many different components of the aircraft design. Typically, there will be a master systems database to which all activities are synchronized at regular intervals--perhaps every month. The clustered suboptimizations represent a set of limited excursions from this base design that are managed in a loosely synchronous fashion on a monthly basis. The configuration management and database system are both critical and represent a major difference between manufacturing and command and control, where in the latter case, real time ``as good as you can do'' response, is more important than a set of precisely controlled activities. These issues are characteristic of HPDC where, although loosely coupled, the computers on our global network are linked to ``solve a single problem.''
ASOP is designed as a software backplane (the NII) linking eight major services or modules shown in Figure 5. These are design (process controller) engine, visualization, optimization engine, simulation engine, process (manufacturing, productibility, supportability) modeling toolkit, costing toolkit, analytic modeling toolkit, and geometry toolkit. These are linked to a set of databases defining both the product and also the component properties. Parallel computing is important in many of the base services, but HPDC is seen in the full system.
Figure 5: Affordable Systems Optimization Process (ASOP) Implemented on the
NII for Aeronautics Systems