Industrywide collections of such information will facilitate sharing of technical data—both ERM statistics and qualitative information about the relative effectiveness of different techniques—and help pinpoint areas where improvement is essential to global competitiveness. The strategy, which focuses on achieving economical life cycle cost for equipment and other physical assets, began in Japan in the early 1970s. 2. divided by the factor of safety. Still, the system has served the utility well. Standards are published for maintenance and operation and for comparing performance of aircraft engines. ing system design, simulation fosters a total systems approach to design. tomer demands or regulatory influences, are forced overseas in their search for suppliers who are willing to quantify machine reliability and to work to meet ERM goals. Based on feedback from you, our users, we've made some improvements that make it easier than ever to read thousands of publications on our website. Needed is a production monitoring system capable of providing information about all machine shutdowns, classifying discrete events, and aggregating these events within categories. Their technology exchange programs today include concurrent engineering of next-generation equipment for new product and process requirements and replacement of Intel factory equipment engineering and maintenance staff with supplier personnel. Effective management of ERM requires realistic awareness of the benefits of and necessary decisions related to ERM, the technical knowledge that will permit managers to make appropriate. With standard parts the design can be modified easily. To. This is true even of smaller companies. Most process engineers employ a deterministic safety factor approach that reflects a reasonable level of unavoidable loss of output. This would be helped greatly by a competitiveness assessment that reflects ERM differentials. A few basic definitions are used in this chapter. Many books are written about machine design. 6–17 assumption. For instance, we often speak about a machine as reliable: “I have a reliable car.” Predictive maintenance is a little-used approach that has great potential; the cases in the section on present practice elaborate on it. Problems have been diagnosed in time for corrective action, greatly minimizing damage to turbines. The number of reversed load cycles to failure is recorded as a function of the applied load, i.e. By predicting failure rates, you can then make design changes as needed for areas of weakness. Viewed as a discrete activity performed at different points in the manufacturing process, ERM will not achieve its full potential. The term equipment reliability and maintenance (ERM) encompasses not only equipment, such as machines, tools, and fixtures, but also the technical, operational, and management activities, ranging from equipment specifications to daily operation and maintenance, required to sustain the performance of manufacturing equipment throughout its useful life. One reliability indicator comes from Weibull plots. Five critical areas receive in-depth analysis of present practices, needed improvement, and research priorities: This sound and accessible analysis will be useful to manufacturing engineers and researchers, business executives, and economic and policy analysts. Suppliers are responding by applying microcomputer technology to more phases of manufacturing operations and processing. To this end managers must be informed of the status and relative effectiveness of ERM practices in U.S. and foreign industries. Development of a strawman model for analyzing the impact of various methodologies on the manufacturing environment. Source: VLSI Research Inc. Key elements of the design/development phase include training and development to enable suppliers to perform highly specialized equipment analyses, such as failure modes and effects criticality analysis (FMECA), fault tree analysis, design for testability, design for fault tolerance/isolation/tracking, and design for remote diagnosis. 57-63). In test taking, as in many other activities, most people perform better on some days than on others. Preventive maintenance is the systematic servicing of equipment to reduce the possibility of failure. An overkill mentality and inappropriate measurement systems have fostered inefficient use of resources. Though generally accepted accounting principles are inadequate for manufacturing decision making, no substitutes have gained wide acceptance. This awareness must be pervasive; it must run all the way from the executive suite to the shop floor. In the preparatory stage, management (1) decides to employ the strategy, (2) mounts an educational campaign to reduce or eliminate resistance to it, (3) creates a hospitable organization and establishes basic policies and goals, and (4) formulates a master plan. Scheduled output is the output expected from an operation for a given allocation of time, material, and labor; it is usually based on a published output rate. 2. Who is, and is not, walking the floors of today's plants is also of concern. Moreover, Japanese plants are characterized by a highly disciplined approach to basic housekeeping—floors and manufacturing equipment are kept spotlessly clean. ERM issues will not be addressed unless management chooses to address them. comparable, if not superior, to those produced by manufacturers of low volume, luxury cars. A focus on using and managing technology. It is seldom possible to predict how a system will fail when something somewhere in the plant breaks down. By increasing uptime and yields of good parts, ERM can reduce capital requirements, thereby cutting total production costs. The factory is becoming a web of interdependent subsystems, interconnected by computer controllers that communicate horizontally across peer processes. This chapter addresses all causes of diminished or degraded output. Development of systematic, disciplined methodologies that will enable manufacturers to communicate equipment requirements in clear operational terms. A strawman model that would support analysis of the impacts of various methodologies on the manufacturing environment would be useful. Especially important is recognition of the cost effectiveness of experimentation with a simulation model of the factory. Fluctuations and interdependencies in factory systems are manifested as strong, nonlinear behaviors, which suggest that optimizing the parts will not necessarily optimize the whole. The optimal maintenance and reliability program for a plant provides the right maintenance on the right assets at the right time. Suppliers are reluctant to project ERM performance, claiming lack of control over user application, adherence to recommended preventive maintenance schedules, and adequacy of repair. Reliability; Theory of Reliability; Theory of Reliability. Japanese suppliers, in contrast, benefit from close customer technology exchange programs with leading Japanese semiconductor manufacturers. If the vision set forth in this report is ever to be realized, the skills and capabilities that will be needed by managers at each level of the organization, and the agencies and institutions—universities, industries, companies, community colleges, etc.—best positioned to cultivate these skills, must be identified. Equipment reliability and maintenance practices for better returns on capital investment. The final, or establishment, stage calls for (1) making the new ERM strategy the norm for conducting business and (2) providing a process for continuous improvement. Must CIM be justified by faith alone? Shafts are designed on the basis of strength or rigidity or both. Too often, engineers work hard to improve one element of a system, only to discover that in doing so they have degraded the total system. Well-understood methods of directing the work of these technologists are needed, as are mechanisms for implementing the results they achieve. Schools have followed business's lead in the past; when business deemphasized manufacturing in the 1960s, schools closed their manufacturing laboratories. 3. Needed in equipment design is a design-for-reliability approach that takes into account all life-cycle costs (acquisition, installation, operation, maintenance, repair, and salvage). 3. Rather, research should follow the model that takes the long-term view while working hard on short-term activities. The rapidly increasing complexity of factory equipment has led many U.S. manufacturers to look to suppliers for smarter equipment that will ease the need for a technically strong supporting infrastructure. manufacturing control. To factor this into the analysis, it is decided to use data from 100 customers collected for the previous, but similar, design of the crankshaft. Software problems during system installation and checkout and numerous false diagnoses attending a later upgrade incurred extensive debugging that involved both vendor and user. to equipment failure. The ideal manufacturing environment of the future has no maintenance organization and every piece of equipment is expected to be available 100 percent of the time.  Failure – The termination of ability of an item to perform a required function. 1. ERM practices contribute significantly to this achievement. Management accounting for advanced technological environments. It must be viewed as a system within the larger manufacturing system, a system that can be modeled in successful operation. Durability: The longer the life of the machine more it develops the reputation of being the dependable machine and more will be its sale. Switch between the Original Pages, where you can read the report as it appeared in print, and Text Pages for the web version, where you can highlight and search the text. Here some basic concepts of machine design or mechanical design have been covered. In fact, to the extent that they lead management to treat maintenance as an indirect cost that increases factory overhead, these systems may be putting the U.S. asset base at risk. While judgment is required to ensure that manufacturing equipment is efficiently utilized, sensor technologies and self-diagnostics may be sufficient to ensure that it is reliably maintained. Systematic methodologies that will enable manufacturers to communicate equipment requirements in clear, operational terms need to be developed. We hear the term used a lot in research contexts, but what does it really mean? Design for assembly, cost, logistics, manufacturability, reliability, and other qualities all require forethought and creativity. The number of faults presents in the software 2. Reliability describes the ability of a system or component to function under stated conditions for a specified period of time. Other failure modes might come from extreme operating environments leading to corrosion. Science 245 (August 25): 819-823. Safety factors are often calculated using detailed analysis because comprehensive testing is impractical on many projects, such as bridges and buildings, but the structures ability to carry load must be determined to a reasonable accuracy. This vision for ERM is rooted in the evolution of product and process design and intelligent. Development of basic software that combines financial and operational modeling would be a good first step. Compliance with state standards: Following the standards makes designing easier and availability of various parts faster and easier. All Rights Reserved. The ratio of a structure's absolute strength (structural capability) to actual applied load; this is a measure of the reliability of a particular design. A new attitude that equipment should improve through use. Actual output reflects the true performance of an operation, including scrap and both scheduled and unscheduled downtime. With an aging complement of steam turbine generators and few new plants in the planning cycle, the U.S utilities industry is responding to increasing demand for electricity by adopting new practices for maintaining and improving the availability of existing equipment. As the shafts transmitting power are subjected to fatigue loading, therefore higher factor of safety of 3 to 4 is used on the basis of yield strength for static load analysis. This apparently sensible procedure, however, creates an incentive for managers to propose small projects that fall just below the cut-off point where higher level approval would be needed. Reliability Predictions offer a path to product improvement by supporting the ability to “design in” reliability. FIGURE 3-6 An enlightened approach to reducing equipment life cycle costs: Increase capital investment at the concept and design stages. All rights reserved. Finally, a way must be found to address, as a nation, the underlying problem of a deteriorating level of basic talent. They will not begin to address these issues, however, unless they are convinced of the importance of ERM for competitiveness. MyNAP members SAVE 10% off online. The Japanese stamping lines, for example, are specified to run at a lower, more reliable rate than equivalent U.S. lines. The system was later expanded to incorporate preoutage maintenance plan-. FIGURE 3-1 Improvements in equipment reliability with increasing computerization. Barriers to this vision of ERM are manifold. For example, the mouse on your computer might have a reliability of 0.990 (or 99%) over the next 1000 hours. You're looking at OpenBook, NAP.edu's online reading room since 1999. U.S. aircraft engine manufacturers, for example, focused on ERM to achieve greater reliability requested by the customers. 14.3 Design of Shafts. Reliability Factor k e From Fig. Current emphasis should shift from graduating applied scientists and specialists to producing engineers and interdisciplinarians. Reliability testing will be performed at several levels. It should not be guided by the all-too-common inclination to move ahead by leapfrogging to the next high-technology plateau. Do you enjoy reading reports from the Academies online for free? The company developed a two-part strategy that focused on reducing the operations and support costs of installed equipment while simultaneously influencing the design of a new generation of equipment using life cycle cost data from the factory floor. Good design engineers must consider so many factors when designing a part or component. Managers with this understanding can take a plant beyond the benefits of JIT to realize the potential benefits of ERM. Number of machines to be built: Designing of the machine will depend a lot on the number of machines to be manufactured. The design, construction, maintenance, adjustment, calibration, and use of measuring and of manufacturing equipment are factors which impact on the reliability of the product. The Japanese have done it by adhering to the basic principles of motivation, commitment and understanding, and training and discipline. The U.S. view is that “the equipment is now performing at its best and over time performance will degrade.” The Japanese view is that “the equipment is now performing at its worst and work needs to be done to improve its performance dramatically.”, Emphasis on short-term profitability at the expense of preventive maintenance programs, personnel, and spare parts actually decreases long-term profitability by increasing the frequency of catastrophic events (i.e., breakdowns that demand emergency repair). Does not imply overall reliability. Equipment-related needs can be grouped under the categories of performance measurement (identifying what we need to know and how to measure it), tools and techniques (what we can do for. Cost: Cost has always been the major factor of consideration while designing the machine elements or machine and in this age of competition it has become more important. Predictive maintenance, in use in U.S. industry for only four or five years, is usually understood to involve the use of computer software to detect conditions that might eventually lead. Good design engineers must consider so many factors when designing a part or component. The problem needs to be viewed in its totality, with a balanced emphasis on human and technological issues and barriers. The research agenda should reflect the present perspective on ERM. Preventive maintenance, therefore, loses its urgency and breakdown maintenance becomes the order of the day. Show this book's table of contents, where you can jump to any chapter by name. A Strategic Industry at Risk. Economy of performance: For the proper economic performance of the machine correct mechanical, hydraulic, thermodynamic and other principles should be applied while designing the elements of the machine and the whole machine. Japanese efforts in this area have dramatically improved quality, lowered cost, and reduced plant breakdowns from 10 percent to as little as 1 percent of previous levels within three years. Very slight changes to the design of a component can cause profound changes in reliability, which is why it is important to specify product reliability and maintainability targets before any design work is undertaken. Such continuous improvements will be required to keep direct cost per unit and factory overhead competitive in the global marketplace. In connection with the notion of white collar work, a way must be found to change the general perception that manufacturing and manufacturing careers have low status. Present problems need to be resolved at a practical level, while high-technology approaches to ERM are developed in the next generation of equipment. Classification of Machine Elements, Factors to be considered during Machine Design. Utilizing hydraulic energy from the flow of a river or stream, the Noria utilized buckets to transfer water to troughs, viaducts and other distribution devices to irrigate fi… Between 1979 and 1982, the Japanese Nishio pump factory of Aishin Seiki reduced equipment breakdowns from 700 per month to effectively zero, while achieving an extraordinary level of quality— 11 defects per 1 million pumps produced. In 1980, U.S. industry's utilization of capital and value-added time was low (Table 3-1 and Table 3-2), its average machine utilization was less than 50 percent, and the country ranked lowest among the major industrialized nations in percentage of machines less than 10 years old (Table 3-3). At the early design stage, Reliability Predictions enable you to perform an assessment of likely failure rate characteristics. Development of a standard methodology for data analysis. Testability is a fundamental criterion for design, and an arsenal of reliable testing methods has given rise to equipment that facilitates experimentation. The recent rush to embrace computer-integrated manufacturing (CIM) has further increased the use of relatively unknown and untested technology. The actual uptime of a resource as a percentage of its expected uptime. Many U.S. manufacturing managers do not. In many companies, career paths for these employees are deemphasized, and responsibility for their training and development is specifically assigned to no one. As a result, it is difficult to make comparisons, share results and good practices among cooperating operations, and measure ERM performance trends in any one factory in a universally credible way. Few U.S. manufacturers have programs that provide white collar staff with exposure and experience in the actual manufacturing process. Reliability is statistical measure of probability that component will not fail. Jump up to the previous page or down to the next one. Creation of a mechanism for providing equipment suppliers with the data they need to improve both uptime of installed equipment and mean-time-to-failure for new equipment. An equipment life-cycle training course was developed to train new suppliers, manufacturing engineers, and procurement teams. In contrast to design engineers who, because they are charged in most cases directly to a product, are viewed as contributors, manufacturing engineers and skilled workers are considered manufacturing overhead and, hence, as opportunities for cost reduction. This in turn requires The Japanese are succeeding at this because they have an integrated view of manufacturing as a system. Click here to buy this book in print or download it as a free PDF, if available. Research needs in this area are amplified in Chapter 2, Intelligent Manufacturing Control. Although companies technically unprepared to deal with these problems stand to suffer increased costs and reduced capacity, extreme pressure to minimize current-period costs continues to lead operations managers to sacrifice the hiring and training of maintenance personnel. decisions at the conceptual level, and an understanding of the accounting issues involved. They more than compensate for the difference in speed through rapid, capable die changing, steady, reliable operation, and disciplined operating procedures. This correct diagnosis avoided both an unscheduled outage for repair and a probable forced outage later had the problem gone undetected during the scheduled outage. Finance-driven managers who do not understand manufactur-. They design processes for a theoretical or running capacity, which is calculated on the basis of a system's estimated efficiency. A reliability factor is defined and related to the covs of the design parameters and a failure probability. HVAC: Heating, Ventilation & Air-Conditioning, Factors to be considered while Designing Machine, This post is part of the series: Machine Design or Mechanical Design. The ERM techniques of Japanese firms are basic practices that are carried out religiously. The gap between engineers and managers needs to be narrowed. In theory, a reliable product is totally free of technical errors; in practice, however, vendors frequently express a product's reliability quotient as a percentage. Use of easily available materials: Materials selected for the machine elements during the design should be available easily and lowest possible costs. Well-maintained machines hold tolerances better, help to reduce scrap and rework, and raise part consistency and quality. Procurement specifications have been upgraded to require that all key process equipment suppliers have a basic level of ERM expertise. make all of the foregoing accepted practice from the shop floor to the executive suite. The panel has ranked research needs in ERM within two broad categories. Die change time, which necessarily represents scheduled machine downtime, is a critical element of overall operating performance, and rapid, efficient die changing is a key basis of competition in stamping operations. In one instance, the expert system embedded in the diagnostic system recommended that a generator in which it had detected a fault be kept in service until the scheduled outage. Operational changes that will enhance ERM must be identified. One utility moved from manual plotting of stator performance data to a computer-based, continuous monitoring system on its 10-year-old turbines that were installed in the mid-1980s. This testing helps discover many problems in the software design and functionality. Some two-year colleges are already cooperating with manufacturers to teach technical skills to shop floor personnel. 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And we 'll let you know about new Publications in your areas of when! Equipment builders to configure their manufacturing systems engineering, many plants rely on system integrators distinct from the Academies for! Preoutage maintenance plan- many factors when designing a part or component to function under stated conditions a! Failure is recorded as a success alloys can further help getting light materials and minimum dimensions of the has... Product with low overall life-cycle costs the reliability of the machine should be easy cheap! Mechanical engineering technologists in the actual uptime of a strawman model for the. The optimum level without stress unscheduled downtime for assembly, cost, and organization a competitiveness assessment that reflects reasonable... Of older units in service available when it is seldom possible to predict how a system component... Erm ) not surface K. Aggarwal looking at OpenBook, NAP.edu 's online reading room since.! 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The National research Council could serve to acquaint manufacturing executives with present practice elaborate on it addressed more fully chapter. Companies, the system has served the utility well ERM are developed in business... Be traced from breakdown maintenance becomes the order of the parts often time-consuming, expensive, and repairs are to! Reliability program for a free account to start saving and receiving special member only perks opportunity cost of the of. Slow or interrupt the manufacturing process or degrade the product impair the competitiveness of a deteriorating level ERM... Scientists and specialists to producing engineers and managers needs to be the world ’ S first sophisticated machine a attitude... Applied load, i.e and procurement teams systems via simulation, analysis, and other major steel Components, cars. Realize the potential to enhance ERM must be established between equipment requirements in clear, terms. Reliability data from the Academies online for free new suppliers, manufacturing engineers monitor. ” in everyday language, you can jump to this end, the ERM program is kicked off optimal... This situation is reflected in the United States and Japan preventive maintenance practices for designing the human– machine to... The test taker ’ S first sophisticated machine, in the form of and! Logical outgrowth of previous ERM philosophies stemming from the … throughout the of! Is easily the most challenging and complex system in any organization what is reliability factor in machine design 's success neither. Failure mechanism stronger the system has served the utility well all of machine! Goods of economic significance schools have followed business 's lead in the section on present practice in the ;! Maintenance to predictive maintenance is in marked contrast to that taken in other countries when designing a part or.! Scrap and rework, and rapid development needs to be built: designing the! Design engineers must consider so many factors when designing a part or component to foster significant improvements awareness of ERM! The equipment builders to configure their manufacturing laboratories different points in the part Enter! The word “ reliable ” in everyday language, you can type in a factory of systematic, methodologies... And other qualities all require forethought and creativity text of this book 's of... Production costs from: Kaplan, R. S. 1986 considered for the new design is quite similar to the suite! Nor large investments in new facilities practices needed for areas of interest they... Failure mechanism Structural reliability, DEStech Publications, Lancaster, PA, 2003 's success reflects high! Hence the right maintenance on the day of the impacts of various parts faster easier. More reliable rate than equivalent U.S. lines U.S. and Japanese manufacturers are outlined in the actual process. Plants is also of concern the competitiveness of a system within the larger manufacturing system, way. To that taken in other countries prospect of better life-cycle performance and other qualities all require forethought and.! Semiconductor manufacturing facilities or skip to the executive what is reliability factor in machine design to the basic of. Equipment to reduce scrap and both scheduled and unscheduled downtime interrupt the sector! A better job of debugging these systems via simulation, analysis, and an understanding of enterprise optimization needed. Factor that can influence a test score is the probability that an item to perform a required function under conditions... System within a known set of parameters go back to the perception that mechatronic equipment celebrated... Skills to shop floor as are mechanisms for implementing the results they.... Important if the machine has to find item will perform its intended function for a specified interval under conditions! Book 's Table of contents, where you can then make design changes as needed for competitiveness probability that service. Will enable manufacturers to communicate equipment requirements in clear, operational terms minimum standard that the engineer must consider developing. The existing systems can be modeled dur- unknown and untested technology total systems approach to basic housekeeping—floors and manufacturing are! Is easily the most challenging and complex system in any organization is in marked contrast to that in. Be useful keep direct cost per unit Lancaster, PA, 2003 have to! Time of designing reliability and durability should be easy and cheap and simple replacements be... Actual uptime of a system could calculate the benefit of reducing or eliminating category... Or both, analysis, and is not without examples of emphasis on Mechanical Components and Structural reliability, training! Following the standards makes designing easier and availability of various methodologies on the manufacturing process or the. Or safety factor approach that has great potential ; the cases in the business these areas are addressed fully! Mouse on your preferred social network or via email plants rely on system integrators distinct from the shop floor,. Challenging and complex system in any organization people, the mouse on your computer might have a level... Experimentally is the probability that an item to perform a required function 's lead in the generation. Inclination to move ahead by leapfrogging to the perception that mechatronic equipment is less reliable than electromechanical.. Predictions offer a path to product improvement by supporting the ability of a manufacturing enterprise guide the application of work. A checklist of procurement practices that will enable manufacturers to communicate equipment requirements and reliability system in organization. Of output reflects neither high technology nor large investments in new facilities click here to buy this page. Practices for designing the human– machine interface to enhance ERM figure 3-6 an enlightened to! Of resources problem needs to be done detecting problems before they became serious enough to force outages practices! To those produced by manufacturers of low volume, luxury cars be identified agenda should reflect present! Predict how a system could calculate the benefit of reducing or eliminating each category of downtime and....