MTTR and MTBF are the independent variables in the availability function, A: You can also derive some other functions from this one, including the probability of failure F, which is 1-A; and reliability (R) which is 1/F, or 1/ (1-A). 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 total abandonment of tradition, or complete cultural change, is neither possible nor desirable, U.S. manufacturers may need to import, adapt, and fine-tune techniques from other countries such as Japan. It should not be guided by the all-too-common inclination to move ahead by leapfrogging to the next high-technology plateau. %%EOF
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. ERM must be recognized as an integral part of manufacturing that has a major impact on quality and productivity. Especially important is recognition of the cost effectiveness of experimentation with a simulation model of the factory. If U.S. machine tool utilization, for example, were to go from 50 percent to 100 percent, investment could be cut in half. No available method of measuring system reliability (e.g., equipment effectiveness = availability × speed ratio × yield) has yet been widely accepted by U.S. manufacturers, and manually collected production downtime data are questionable, inasmuch as waiting time for repairs is seldom reported. Develop a maintenance strategy based on equipment criticality- RCM, PMO or RTF. Many of these issues are addressed more fully in Chapter 6, Manufacturing Skills Improvement. Though generally accepted accounting principles are inadequate for manufacturing decision making, no substitutes have gained wide acceptance. 2. This volume presents a concise and well-organized analysis of new research directions to achieve these goals. Not a MyNAP member yet? Aishin Seiki's ERM practices aim to maximize equipment effectiveness in terms of both quality and productivity by: establishing a total system of productive maintenance covering the entire life of equipment; involving all departments, including equipment planning, equipment usage, and maintenance; requiring universal participation by top management as well as shop floor personnel; and. Research needs in this area are amplified in Chapter 2, Intelligent Manufacturing Control. Source: VLSI Research Inc. impact of these integrated systems on capital investment alone is significant (forgetting impact on quality, cost, and lead time). SUBSTANTIAL CAPITAL investments, in the form of facilities and equipment, are required for manufacturing almost all goods of economic significance. Product and process engineers should be involved in manufacturing decision making, with financial analysts supplying guidance. U.S. manufacturing will want to jump to this futuristic plane from its present plateau. Reliability was first practiced in the early start-up days for the National Aeronautics and Space Administration (NASA) when Robert Lusser, working with Dr. Wernher von Braun's rocketry program, developed what is known as \"Lusser's Law\" . 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. The reliability of the measures are affected by the length of the scale, definition of the items, homogeneity of the groups, duration of the scale, objectivity in scoring, the conditions of measuring, the explanation of the scale, the characteristics of the items in scale, difficulty of scale, and reliability estimation method. An equipment life-cycle training course was developed to train new suppliers, manufacturing engineers, and procurement teams. Biological activity-One of the endproducts of humidity/deposition of damp layer is growth of fungi. Academic emphasis on graduating career or professional engineers. The replacement and displacement of conventional electro-mechanical factory equipment by mechatronic equipment have given rise to a very different set of reliability and maintenance requirements. U.S. aircraft engine manufacturers, for example, focused on ERM to achieve greater reliability requested by the customers. Interpretation of reliability information from test manuals and reviews 4. A focus on using and managing technology. Since 1987, Intel Corporation has used ERM techniques to increase uptime and speed throughput for both the currently installed and the next generation of equipment. A better job of debugging these systems via simulation, analysis, and rapid development needs to be done. 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. Who is, and is not, walking the floors of today's plants is also of concern. In a highly competitive world market, a manufacturer that needs two machines to produce what another manufacturer, by assuring the reliability of its equipment, can produce with one, will not be cost competitive. Veteran engineers in one Japanese company with fewer than 50 employees, for example, developed all of the firm's equipment, tools, and dies. An understanding of enterprise optimization is needed to guide the application of technical work in the plant. A standard methodology for measuring the performance of ERM is needed, as is a way to quantify the benefits of ERM for top management. Manufacturing of and with Advanced Engineered Materials, The National Academies of Sciences, Engineering, and Medicine, The Competitive Edge: Research Priorities for U.S. Manufacturing, Appendix B: Panels of the Committee on Analysis of Research Directions and Needs in U.S. Manufacturing. A new attitude that equipment should improve through use. Few U.S. manufacturers have programs that provide white collar staff with exposure and experience in the actual manufacturing process. ITG SUBJECT: RELIABILITY OF MANUFACTURED PRODUCTS. Rapid product realization techniques to speed delivery to the marketplace. In short, plant managers are given short-term cost-reduction targets that only can be achieved by deemphasizing maintenance staffs and equipment repair, the true costs of which will appear only over the long term. ... then you will be able to directly affect product quality. The trend toward integrating mechatronic equipment into factorywide systems provides a framework for extensively exploring and exploiting this approach. Operational equipment reliability, and the resulting plant uptime, are inversely linked to the number of risks you allow your equipment and machinery to suffer. This would be helped greatly by a competitiveness assessment that reflects ERM differentials. 1. Institutionalize a program that engages operators with equipment reliability focus goals. The strategy, which focuses on achieving economical life cycle cost for equipment and other physical assets, began in Japan in the early 1970s. 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. Because management needs both knowledge and data to know what to do and how to do it, a concurrent effort must be mounted to identify and supply the hard data without which even an enlightened management will be unable to identify the areas that need improvement. Operational changes that will enhance ERM must be identified. Japanese companies that have excelled in this area characteristically have the ability to develop and produce their own equipment. 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. Equipment design employs new approaches that use broader data bases. The intent was to develop and standardize a human performance coding, analysis and management system throughout t… Source: Intel Corporation, 1989. For example, a maintenance professional intentionally using a tool on a piece of equipment to damage it. 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. Washington, D.C. November 1989. This approach should delineate basic principles that are demonstrably effective and universally applicable. h�bbd``b`�$���=��$X� �O ��u�� ���f�XSA,7��Zb ���L��A�10�K�g�� � _+
FIGURE 3-5 For photolithography, attempts to increase mean time between failures have yielded a 30% increase in availability and an approximately 30% decrease in area throughout, while achieving a 10% reduction in total fabrication throughput time. In any real manufacturing environment, some output inevitably is lost because of factors like shift changes, materials defects, maintenance, product changeovers, and operational inefficiencies. RAO: INFLUENCE OF ENVIRONMENTAL FACTORS ON COMPONENT/EQUIPMENT RELIABILITY 123 occur. Management accounting for advanced technological environments. FIGURE 3-6 An enlightened approach to reducing equipment life cycle costs: Increase capital investment at the concept and design stages. Events that slow or interrupt the manufacturing process or degrade the product impair the competitiveness of a manufacturing enterprise. These figures are often given on a yield basis (e.g., output per unit of time or material input). and vertically to supervisory controllers above or slaves below. performance is about response time - how fast a message can be sent or how quickly a document can be retrieved. Over time, a host of little investments, each of which delivers savings in labor, material, or overhead cost, can add up to a less-thanoptimal pattern of material flow and to obsolete process technology. Moisture absorbed by insulating material results in lowering of surface and volume resis-tivities. Fundamentals: Understanding reliability terminology and factors that affect power supply reliability. Preventive maintenance practices in this industry evolved by trial and error. Berkeley,CA: University of California at Berkeley, October 1980. ing operations and competitiveness can be misled by engineering and production managers who specify low rated capacities and scheduled yields. Software maintenance and lack of skills have emerged as major contributors to the perception that mechatronic equipment is less reliable than electromechanical equipment. But without substantive supporting uptime data, it is difficult to convince manufacturing management to operate otherwise. 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. Well-understood methods of directing the work of these technologists are needed, as are mechanisms for implementing the results they achieve. 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). Predictive maintenance is a little-used approach that has great potential; the cases in the section on present practice elaborate on it. MyNAP members SAVE 10% off online. You're looking at OpenBook, NAP.edu's online reading room since 1999. Viewed as a discrete activity performed at different points in the manufacturing process, ERM will not achieve its full potential. The problem needs to be viewed in its totality, with a balanced emphasis on human and technological issues and barriers. U.S. manufacturing also needs an equivalent to the Japan Institute of Plant Maintenance—an active group unencumbered by antitrust legislation and supportive of joint R&D, production ventures and standard-setting efforts—to spearhead advances in ERM practice. Management leadership is essential to solving manufacturing 's problems because only management is positioned to have the overview essential for effective decision making and leading. Cost models associated with short-term measures, which rapidly drive future costs to zero in a present value analysis using a relatively high rate of return, lead managers to emphasize initial purchase price in equipment acquisition. 1. Making them optimal is the key to human reliability. Preventive maintenance is the systematic servicing of equipment to reduce the possibility of failure. 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. It has been well established that social and psychological factors are important to worker satisfacti… Many U.S. manufacturing managers do not. Finally, a way must be found to address, as a nation, the underlying problem of a deteriorating level of basic talent. This framework consists of creating a vision and mission, ensuring availability of resources and empowering people to achieve organizational excellence. General attention to the inadequacy of the basic level of talent. 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 addition to a broader professional Master of Science degree, greater emphasis is needed on the production of master technicians. High acquisition and operating costs (stamping dies and presses constitute a substantial part of the capital investment in automobile manufacture) lead automakers to run multiple sets of dies on a given line. In addition to understanding the human error types it is necessary … Needed is a production monitoring system capable of providing information about all machine shutdowns, classifying discrete events, and aggregating these events within categories. Software problems during system installation and checkout and numerous false diagnoses attending a later upgrade incurred extensive debugging that involved both vendor and user. Share a link to this book page on your preferred social network or via email. The suppliers, largely isolated, are in most cases not likely to commit resources to providing a capability that many U.S. manufacturers, because they have not yet understood its value, have not demanded. Rather, research should follow the model that takes the long-term view while working hard on short-term activities. The implementation stage calls for (1) ensuring early successes and hands-on experience by focusing initial efforts on equipment that offers the most potential for improvement, (2) establishing an autonomous maintenance program for operators, (3) creating a system of planned maintenance that anticipates an increase in work load, (4) improving operating and maintenance skills through training, and (5) developing a prototype equipment management program. Suppliers are responding by applying microcomputer technology to more phases of manufacturing operations and processing. 0
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. Environmental Factors Environmental factors such as uncomfortable room temperature, or distracting sounds are one form of unsystematic errors. The term artificial intelligence is appearing in sales literature that increasingly is offering catalog solutions as alternatives to technical proficiency. 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. comparable, if not superior, to those produced by manufacturers of low volume, luxury cars. Arguments that blame insufficient capacity on old machines that cannot be replaced because of high cost are suspect because the most cost-effective increase in U.S. manufacturing capacity may well be achievable through improved maintenance practices for existing equipment. This also offers an opportunity to review the supplier’s quality control strategies, the current state of equipment, and the workforce’s technical competence. ning, the cost of generator outages, prevention of in-service failure, and the increasing percentage of older units in service. Partnerships with key equipment suppliers were critical to the success of both parts of the program. In Japan, for instance, many firms are engaged in a 10-year program to upgrade predictive maintenance to the point where ERM becomes the responsibility entirely of operators. 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. This is true even of smaller companies. The research agenda should reflect the present perspective on ERM. It must be viewed as a system within the larger manufacturing system, a system that can be modeled in successful operation. Development of guidelines and practices for designing the human– machine interface to enhance ERM. Broken pencil, momentary distraction by sudden sound of a train running outside, anxiety regarding non-completion of home-work, mistake in giving the answer and knowing no way to change it are the factors which may affect the reliability of test score. U.S. industry is not without examples of emphasis on ERM. In addition, practices that will promote effective implementation and continuous improvement of ERM must be developed. Development of standards for design and test, for measuring and evaluating ERM, and for operator–equipment interfaces, would be a great facilitator in each of the areas discussed above. Its purpose is to measure the probability that a piece of equipment in a failed state can be restored to normal operating conditions after undergoing maintenance. An overkill mentality and inappropriate measurement systems have fostered inefficient use of resources. Maintenance-program costs are estimated to aid budgeting. Assemble a multidisciplinary team to participate in the equipment reliability process. 2. Maintainabilityrefers to the ease with which maintenance activities can be performed on an asset or equipment. The goal of the strategy is to eliminate the six main downtime losses: losses from setup time associated with periodic changes and adjustments of tools and dies; losses that result from idling, minor stoppages induced by sensors, and blockages of work in chutes; losses attributable to differences between actual and design speeds of equipment; process-related losses associated with defects and reworking; and. The key enablers in creating the culture are enhanced by how the strategic leadership framework is developed. Unplanned downtime results into undesirable indirect cost of maintenance due to losses in production and the idleness of other machines in the production system. The potential. Existing systems offer few incentives for manufacturing managers to ask appropriate questions. In 1989 alone, 51 companies were recognized by the Japan Institute for Plant Maintenance for achieving a level of performance in total productive maintenance that placed them on par with the Nishio factory. The U.S. facilities of Japanese automakers, using U.S. workers to operate three to five presses, often achieve at least twice the productivity of comparable U.S. facilities on a per-line or perpress basis. Methods for conducting validation studies 8. Learn more about how you can improve maintenance practices By allowing the ERM process to be modeled dur-. The very terminology of ERM can impede its adoption and practice. Building a workforce with the multidisciplinary skills needed for competitiveness. Technology of MachineTools, Machine Tool Systems Management and Utilization. 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. Managers with this understanding can take a plant beyond the benefits of JIT to realize the potential benefits of ERM. Must CIM be justified by faith alone? The hard data needed to make a convincing argument to management are hard to find. ... culture. 57-63). This situation is reflected in the radically different perceptions of the performance of newly installed equipment in the United States and Japan. But it is not yet known how to prove ERM's value using generally accepted accounting principles and short-term measurement systems that yield little information on life-cycle costs and benefits of equipment.4. Further, a logical model of machine failure that can relate different kinds of failures, mean times between them, and their causes, is needed. ...or use these buttons to go back to the previous chapter or skip to the next one. Moreover, Japanese plants are characterized by a highly disciplined approach to basic housekeeping—floors and manufacturing equipment are kept spotlessly clean. 54 0 obj
Show this book's table of contents, where you can jump to any chapter by name. Critical specifications must be defined and formulated to ensure reliability and identify pitfalls, stumbling blocks, and best practice. Standard error of measurement 6. Development of standards for design and test, measurement and evaluation of ERM, and operator–equipment interfaces. Over the next several product generations, the cost of such facilities is expected to reach between $500 million and $750 million (Figure 3-2 ). A more enlightened approach to reducing equipment life-cycle costs would be to increase capital investment at the concept and design stages in order to improve equipment reliability, maintainability, and predictability and thereby reduce operations and support costs that inflate factory overhead (Figure 3-6).
2020 factors that affect equipment reliability