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INTRODUCTION

Commercial and military engineering systems proceed through well-defined stages during their lifetimes—initial conceptualization, design, manufacture, distribution, delivery, installation, acceptance, support during operation (including retrofits), and disposal. Two competing goals have emerged relating to these stages and the cost of advanced military systems. The first goal is reducing the time required for design through delivery of a reliable and effective product manufactured in a manner consistent with full-scale production. In the case of military aircraft, pressures prevail to minimize the time from full-scale aircraft development go-ahead to production delivery for operational service. The second goal is to reduce overall system cost, consistent with achieving performance requirements. Both of these goals promote the use of conservative practices during design; however, the first goal (compression of the development cycle) also frequently fosters the need for costly product modifications during later stages of the life cycle.

Experience with military aircraft and other systems reveals that, of the total engineering cost (i.e., all except operational costs) over the system life cycle, less than 10 percent is spent on design, more but still less than 25 percent is incurred in manufacture, and the major expense by far—more than 65 percent—results from required product support such as maintenance and modifications. It is also widely recognized that opportunities for cost reductions decrease (and the cost for modifications increases) rapidly as the system matures—i.e., as design and manufacturing processes and procedures are finalized (Figure 1-1).

The two goals, reduced development time and lowered overall cost, require improved information quality and information management throughout the life cycle, taken in this study as extending from design through field support. This is particularly important during the design phase so that more issues can be considered and analyzed, trade-off studies performed, and design compatibility with subsequent manufacture and product support achieved.

This requires providing the designer complete information about the product, its anticipated service performance envelope and environment, and capabilities and limitations of production and maintenance. This information should be sufficiently comprehensive to cover the life cycle of the product in a design-usable context. Ideally, with such information, an engineering strategy could be developed to yield specific desired benefits—for example, lowest initial cost, lowest maintenance costs, and lowest life-cycle costs. This last option has been termed unified life-cycle engineering (ULCE) and is the subject of this report.



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Enabling Technologies for Unified Life-cycle Engineering of Structural Components 1 INTRODUCTION Commercial and military engineering systems proceed through well-defined stages during their lifetimes—initial conceptualization, design, manufacture, distribution, delivery, installation, acceptance, support during operation (including retrofits), and disposal. Two competing goals have emerged relating to these stages and the cost of advanced military systems. The first goal is reducing the time required for design through delivery of a reliable and effective product manufactured in a manner consistent with full-scale production. In the case of military aircraft, pressures prevail to minimize the time from full-scale aircraft development go-ahead to production delivery for operational service. The second goal is to reduce overall system cost, consistent with achieving performance requirements. Both of these goals promote the use of conservative practices during design; however, the first goal (compression of the development cycle) also frequently fosters the need for costly product modifications during later stages of the life cycle. Experience with military aircraft and other systems reveals that, of the total engineering cost (i.e., all except operational costs) over the system life cycle, less than 10 percent is spent on design, more but still less than 25 percent is incurred in manufacture, and the major expense by far—more than 65 percent—results from required product support such as maintenance and modifications. It is also widely recognized that opportunities for cost reductions decrease (and the cost for modifications increases) rapidly as the system matures—i.e., as design and manufacturing processes and procedures are finalized (Figure 1-1). The two goals, reduced development time and lowered overall cost, require improved information quality and information management throughout the life cycle, taken in this study as extending from design through field support. This is particularly important during the design phase so that more issues can be considered and analyzed, trade-off studies performed, and design compatibility with subsequent manufacture and product support achieved. This requires providing the designer complete information about the product, its anticipated service performance envelope and environment, and capabilities and limitations of production and maintenance. This information should be sufficiently comprehensive to cover the life cycle of the product in a design-usable context. Ideally, with such information, an engineering strategy could be developed to yield specific desired benefits—for example, lowest initial cost, lowest maintenance costs, and lowest life-cycle costs. This last option has been termed unified life-cycle engineering (ULCE) and is the subject of this report.

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Enabling Technologies for Unified Life-cycle Engineering of Structural Components Figure 1-1 Early design determines life-cycle cost. Source: Ashton, presentation to committee. The ULCE concept is consistent with recent Department of Defense (DOD) initiatives in Total Quality Management (Costello, 1988) and Computer-Aided Acquisition and Logistics Support (CALS). These efforts are aimed at the similar objectives of improving the overall life-cycle performance of weapons systems. The term concurrent engineering has become widely used in the government and industry to describe the inclusion of issues such as producibility and supportability early on in the design process. Various techniques including Taguchi Methods (Kackar, 1985), Quality Function Deployment (QFD) (Hauser and Clausing, 1988; King, 1987) and Boothroyd-Dewhurst Design for Manufacture and Assembly (Boothroyd and Dewhurst, 1988) are increasingly employed to improve the design process. These existing methods are not in themselves capable of meeting the technical challenges encountered in achieving an ULCE environment. OBJECTIVE The objective of the study was to identify enabling technologies underpinning ULCE, their readiness for application, and key research and development needed to make them commercially available in a 10-year time frame. This study investigated the status and interplay of various engineering functions employed over the life cycle of weapons systems to meet the goals more successfully than is done at present. Technology needs and opportunities to promote ULCE for a specific class of applications—advanced structural components, typical of those employed in high performance aircraft, requiring extremely high reliability and made in small quantities (fewer than 1000)—were examined. The study was undertaken in response to a DOD request to investigate the enabling technologies required to provide a unified life-cycle engineering environment for structural components. The committee has taken a broad interpretation of the definition of ULCE to include those manufacturing and support processes that accompany product design as well as information quality and flow to support these processes.

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Enabling Technologies for Unified Life-cycle Engineering of Structural Components The committee aimed at identifying a generic approach and the enabling technologies needed to make this approach realizable within 10 to 20 years. To check the validity of the findings for components made of well-characterized versus emerging classes of materials, the relevance of the generic approach was evaluated by applying the results to two specific cases: a metal disk for the turbine section of jet engines (Appendix A) and fiber-reinforced polymer composites in primary fuselage applications (Appendix B). The committee focused on technical or engineering aspects of ULCE, in contrast to procurement or human-factors issues and directed its attention to weapons systems having the following characteristics: Components that perform a structural role (as contrasted to electronic functions); and Products that will be manufactured in small quantities (fewer than 1000), where mass-production methods may not be applicable. APPROACH The committee report was developed using the sequence shown in Figure 1-2. Each segment of the process was examined in detail. Figure 1-2  Sequence used by committee for this study program. The following items were the primary issues addressed by the committee in its deliberations to arrive at some specific recommendations for future actions:

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Enabling Technologies for Unified Life-cycle Engineering of Structural Components • Identification of current and desired future environments for producing new engineering systems. In the initial phase the following five factors were delineated as independent components of ULCE strategy: design, manufacture, product support, materials, and information flow (see Figure 1-3). For each area, the practices that constitute the present environment of that area were examined. The desired future environment was then determined, representing the technologies, systems, and practices that would make ULCE fully achievable. Chapters 2 through 6 document these environments for the five factors. The committee drew on relevant experience from nondefense products where lifetime ownership and warranty costs have been important to remain competitive. Presentations by individuals from industry, academy, and government were made to the committee; brief summaries of these presentations are shown in Appendix C. • Development of central needs and concerns and associated enabling technologies for ULCE. The actual (current) and desired (future) environments were compared. Differences were noted and used to develop a listing of needs and concerns, which were further evaluated to Figure 1-3.  Current and future environment.

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Enabling Technologies for Unified Life-cycle Engineering of Structural Components determine their importance. Important needs and concerns were aggregated into four critical issues, each of which summarizes important problems that need to be resolved for ULCE to be fully implemented. These were the basis for identification of enabling technologies to resolve the needs and concerns. These critical issues are discussed in Chapter 7 . The committee used a combination of expert sources, round-table discussion, and vigorous review and re-review to identify, prioritize, and validate the list of enabling technologies required to resolve the critical issues. The "readiness" of the technologies for ULCE was also considered—i.e., whether they are commercially available now, are mature and ready for commercial deployment, are mature but require some redirection or refocus for ULCE, or need fundamental research. • Formulation of an integrated strategy and set of specific recommendations for the enabling technologies. Given the differences in readiness of some of these technologies, the committee developed a time-phased plan to bring them to fruition. The recommendations propose a discrete set of actions to promote selected aspects of the enabling technologies. In addition, examples of research and development (R&D) programs that would implement the recommendations are suggested. This information is given in Chapter 8. UNIFIED LIFE-CYCLE ENGINEERING Two prerequisites that are key to successful ULCE are information quality and information flow at critical junctures during the life cycle of the product. The goal of ULCE must be to provide the information at the inception of design or as close to this as possible, since successful life-cycle engineering requires that all phases of a product's creation and existence be considered when it is designed. Considerations that are before a designer involve the producibility of the item (in quantity and with process and materials variability), the usability of the system (within and sometimes beyond the margin specified for the operating envelope), and the reliability and repairability of the product (again within and beyond the specified domain). At present, major information problems include the limited availability of data on manufacturing and support, particularly limitations that are likely to have an impact on the product, and incomplete (or incorrect) specifications of the operating environment in terms of quantitative engineering property requirements. Even when manufacturing and support information is available during design, its quality may be viewed with suspicion because it may be incomplete or have errors; is based on a small sample of observations; or is framed in an unfamiliar context. This lack of confidence in the quality of information significantly reduces its effectiveness and its impact on the design of products. Information management in ULCE will draw heavily on computer capabilities for processing, storing, and distributing information across functional and geographic boundaries. A key concept for the implementation of life-cycle engineering is that of providing designers with access to new knowledge and information along with powerful tools to manipulate that information. This new capability will significantly enhance a designer's ability to produce the best possible design given all the goals and constraints that must be considered. Computers also will assist in implementing the practices and policies deemed necessary to ensure producibility in manufacturing and supportability in the field by providing information repository services for managing information derived from many sources and used by many users.

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Enabling Technologies for Unified Life-cycle Engineering of Structural Components There are four barriers to the implementation of ULCE: The traditional serial design process needs to be modified to allow concurrent analysis of the design from multiple paradigms. There needs to be a common metric for measuring how good a design is. Alternatives meeting functional requirements must be evaluated in terms of a life-cycle view of the product. Life-cycle cost is probably the best measurement that can be used to compare design alternatives across many functional areas. Since improvements in information flow and information quality alone will not necessarily lead to improvements in life-cycle design, there needs to be a translation of information on current products into design rules for future products. This translation of information is viewed as being technically complex as well as difficult to communicate. In addition to technical issues, many institutional relationships will need to be changed under ULCE, particularly with regard to the present compartmentalization of design, manufacture, product support, materials, and information flow. These institutional changes will affect vendors, suppliers, purchasers, and users. POTENTIAL PAYOFF There have been numerous analyses of both commercial and DOD products to determine where the true costs of ownership are incurred (Symon and Dangerfield, 1980). The consistent result is that there is an exponential growth in the cost of identifying and repairing a defect as the product matures. Design errors can be fixed quickly and "with the stroke of a (light) pen" during design; their resolution during product manufacture usually requires significant cost, and during product use even greater expense, time, and sometimes compromised performance. The hypothesis of the committee was that ULCE would make possible correct initial design of a product, process, and support structure. ULCE would improve the quality of products by making it easier to consider explicitly issues such as manufacturability, maintainability, sustainability, inspectability, readiness, and life-cycle cost in addition to the traditional emphasis on cost, schedule, and performance. Although additional resources, time, and expense would be required initially during all of the design phases, total life-cycle costs would be reduced because the resulting designs would provide products with greater overall quality and performance, thus permitting significant reductions in retrofitting and maintenance. Other gains from the ULCE environment can be anticipated as well. A life-cycle perspective from the designers' vantage point would allow concurrent design processes and thereby reduce the product development cycle time. It would facilitate rapid and efficient response to changes in product functional requirements that inevitably arise during a system's lifetime, and it would enhance the utilization of new technologies. CURRENT AND FUTURE ENVIRONMENT New weapons systems normally are introduced to perform missions that could not be performed previously, and the basis of these systems for military aircraft is application of new technologies to meet flight performance requirements. Typically, several new technologies are introduced at once in support of program objectives. For example, reduced aircraft weight allows

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Enabling Technologies for Unified Life-cycle Engineering of Structural Components improved maneuverability and greater range. Weight savings can be achieved by designing closer to material capacities, by making more precise structural arrangements for load distribution, and/or by using advanced materials that yield better ratios of strength or stiffness to weight or, more typically by a combination of approaches. More rigorous design will demand more reliable manufacture and product support protocols. Improved information flow (both "feed-forward" and "feed-back") among the functions of design, manufacture, and product support will need to accompany the more sophisticated approaches to these functions. It is reasonable to assume that program budgets for future systems will be more restrictive and that fixed-price contracting will become the standard business process. Long-term warranties on serviceability, reliability, and supportability will also be required. Shorter development times may be anticipated in the future to be more responsive to enemy threats and to reduce the initial program cost. Figure 1-1 shows the rapid decay of life-cycle cost reduction opportunities early in the product's life cycle. This decay will continue in the future; a majority of the decisions affecting life-cycle performance and cost will be made well before release to production. Therefore, the future ULCE environment will fully acknowledge this phenomenon and will provide knowledge and tools to be available in the design phase to assess life-cycle parameters. As total life-cycle costs are reduced, the proportions will shift to permit increased effort during design. Of the many changes to be expected in the future ULCE environment compared with the current situation, one feature will stand out: most activities in design, manufacture, and product support that are performed sequentially and independently today will be conducted concurrently and interactively in the future. Information flow today can be characterized as predominantly one-way: from design to manufacturing to product support. Design is a hierarchical process passing consecutively through conceptual, preliminary, and detailed design steps. Different teams and procedures are involved in each step. The overall process extends over several years and hence through numerous personnel changes. The initial design process considers manufacturing only informally. The transition to the factory floor consists of a series of steps from concept through demonstration, validation, full-scale development, and finally production, with a more formal link to design as production nears. Automation is not widely applied to processing, inspection, or assembly activities in industry today. Quality assurance often focuses on post-production inspection. Design and manufacturing attributes that make for difficult product support situations are compensated for by more sophisticated field-testing and maintenance resources or by replacing entire assemblies rather than repairing components. Finally, design, manufacturing, and product support cannot directly incorporate correlations to processing, structure, and properties developed in laboratory research on materials. In the future, the serial design process will be replaced by concurrent processes by providing interactive access for many disciplines (reliability, supportability, manufacturing, etc.) to the design definitions as they are developed. This concurrency will shorten developmental cycles. This, along with improved information systems, will permit a complete audit trail of decisions and authorizations. Products will be designed and represented using features rather than dimensions. It will be possible to evaluate the robustness of a design in expanded operating envelopes, considering variability in manufacturing, materials, and operation. From early in the design cycle engineering will be able to continually analyze the impact of the proposed advanced materials, manufacturing and support processes and control that are critical in state-of-the-art products. Manufacturing will be an integral part of a product resource

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Enabling Technologies for Unified Life-cycle Engineering of Structural Components planning and control system that will link it to design, vendors, quality assurance and field service operations and will provide flexible and effective real-time status, automatic data capture, and process control. Failures and maintenance actions gathered from field experience will be interpreted in ''design guides,'' which will assist in reducing the overall logistics requirements and guide future designs. VALIDITY OF STUDY FINDINGS FOR OTHER PRODUCTS While the committee focused on high reliability and low-volume production of structural components many of the current and future environmental conditions appear to be applicable to structural and nonstructural parts and assemblies in general rather than just airframe structures and propulsion systems. The needs and concerns are also usually valid for these general classes of applications. The enabling technologies are particularly focused on the structural components, and, although some are quite general, the set constitutes a more specific view. The recommendations are also focused on structural components, with some further recommendations limited to military systems. However, much of this report could be applied more broadly. REFERENCES Air Force Systems Command. 1987. Implementation Plan for Unified Life Cycle Engineering (ULCE), March. Boothroyd, G. and P. Dewhurst. 1988. Product Design for Manufacture and Assembly, Manufacturing Engineering, Vol. 100, No. 4, pp. 42–46. Costello, Robert B. 1988. "Implementation of Total Quality Management in DOD Acquisition," Memorandum for Secretaries of the Military Departments, Undersecretary of Defense, Acquisition, 19 August. Darilek, R. E., E. M. Cesar, J. A. Dewar, G. P. Gould, and E. D. Harris. 1987. "Surveying Relevant Emerging Technologies for the Army of the Future. Lessons from Forecast II." July. Rand Corp., Santa Monica, CA (AD-A213821/2/XAB). Goldstein, G. 1989. Integrating Product and Process Design, Mechanical Engineering, April. Hauser, John R., and Don Clausing. 1988. "The House of Quality," Harvard Business Review, Vo. 66, No. 3, p. 63. Jacobs, G. 1980. Designing for improved value. Engineering, Vo. 220, p. 178. Kackar, Raghu N. 1985. "Off-line Quality Control, Parameter Design, and the Taguchi Method," Journal of Quality Technology, Vo. 17, No. 4, 176. King, Bob. 1987. Better Designs in Half the Time, GOAL/QPC. Symon, R. J. and K. J. Dangerfield. 1980. The Application of Design to Cost as Rolls-Royce, Proceedings of a conference on "The Application of Design to Cost and Life Cycle Cost to Aircraft Engines," May. AGARD-LS-10F. ISBN: 92-835-0265-5.