Quality and reliability assessment of hardware and software during the total product life cycle

A major challenge for the computer industry is the need for the development and implementation of an engineering languge which provides continuous linkages and measurement between the customer and all engineering functions internal to the company. Such a language would allow information solution developers and information service providers to be able to continuously monitor the quality and reliability performance of integrated hardware and software products during the complete product life cycle. A quantitative engineering language needs to be developed to provide seamless and continuous linkages between the customer—the user of integrated computer systems—and all of the engineering development and manufacturing functions tasked with designing and building solutions which meet customer needs. A methodology is proposed which addresses this challenge by the implementation of two metrics: total defects per unit (TDU) and the annual rate of events (ARE). These two metrics can measure all hardware, software and computer integration events during the total product life cycle. A methodology is presented which provides a rigorous translation of the ARE metric, monitored at the customer site, into the traditional reliability metrics used by engineering and manufacturing. Algorithms are presented which directly translate AREs into mean time between failures (MTBF), mean time between parts replacement (MTBPR) and mean time between system interruptions (MTBSI). The ARE metric meets the customer requirement of being able to clearly focus on the reliability and availability performance of total systems as a result of hardware and software components, the user interface, and environmental factors. The paper discusses the development and application of integrated TDU and ARE metrics and shows how the total product life cycle quality and reliability of a complex integrated computer and communications solution can be efficiently monitored and managed for improvement during design, manufacturing, and installation performance in an integrated customer environment.     

Forecasting reliability growth

This paper describes a method for estimating and forecasting reliability from attribute data, using the binomial model, when reliability requirements are very high and test data are limited. Integer data—specifically, numbers of failures — are converted into non-integer data. The rationale is that when engineering corrective action for a failure is implemented, the probability of recurrence of that failure is reduced; therefore, such failures should not be carried as full failures in subsequent reliability estimates. The reduced failure value for each failure mode is the upper limit on the probability of failure based on the number of successes after engineering corrective action has been implemented. Each failure value is less than one and diminishes as test programme successes continue. These numbers replace the integral numbers (of failures) in the binomial estimate. This method of reliability estimation was applied to attribute data from the life history of a previously tested system, and a reliability growth equation was fitted. It was then ‘calibrated’ for a current similar system's ultimate reliability requirements to provide a model for reliability growth over its entire life-cycle. By comparing current estimates of reliability with the expected value computed from the model, the forecast was obtained by extrapolation.     

What's new in reliability engineering?

Reliability engineering is responding to the trend to computer-aided design (CAD), and the current emphasis on improving competitiveness through quality. Islands of automation addressing reliability for both hardware design and software engineering exist which are not yet connected, though government–industry teams are developing integrated software packages of reliability (and maintainability) tools. TQM (total quality management) principles are being adopted in many industries, and the U.S. Qualified Manufacturers List (QML) programme, which requires qualification of a process rather than a product, is now used for procuring microcircuits. However, government regulations remain a barrier to creating a ‘quality culture’. ISO 9000 is seen by industry as a requirement for international competitiveness, but criticized by some as counterproductive. Research and development of reliability engineering tools reflect the need for implementation in CAD frameworks, and fuzzy logic analysis has attracted the attention of the theorists.     

Integrating Reliability in Systems Engineering Management

Abstract

Understanding how engineering disciplines, activities, and artifacts are connected between them is key to success as an engineering manager. However, engineering managers are often unaware of these relationships in the area of reliability engineering. This results in omitting necessary reliability activities, incorrectly executing them, and/or executing them at the wrong time. This paper discusses how reliability activities effectively integrate in the system’s life cycle, enabling engineering managers to understand what has to be done, when and why, from a reliability point of view. We contend that this understanding facilitates communication between systems engineers and reliability experts. Eight real cases are presented to show the negative consequences of managing engineering projects without a systemic understanding of reliability. Based on such experience, a number of recommendations are given for engineering managers.     

Evolution of VLSI reliability engineering

Projection indicates that by the turn of the century microcomputer chips will have 100 million transistors and failure rates of less than 10 FIT. Traditional accelerated product life tests and wafer level reliability measurement techniques being developed at present will have severe limitations in resolving the 10 FIT failure rate of complex VLSI circuits. This paper discusses these limitations along with the change in direction that the reliability engineering and manufacturing community will have to take over the next decade to meet the challenge of continuously decreasing failure rate goals.     

The design of mechanical equipment for the limitation of in-service failure

Mechanical equipment design demands a deep understanding of the inherent failure mechanisms likely to be encountered in service operation. Such understanding can result in the eradication or the limitation of the effects of in-service failures. This aspect of engineering design is examined and a case study example, in which the design of stand-by equipment involved the limitation of fretting corrosion, is used as an illustration of the general principles involved.     

The rationale of reliability prediction

This paper is the first of what is intended to be a series of papers which investigate the foundations of reliability theory, particularly when applied to the prediction process. It will contrast current reliability practice against those practices common in normal science and engineering. The claim will be made that in general the prediction process as used in reliability, when stripped of the mathematical embellishments, is no more than simple enumeration: a method long held by the philosophers of science to be unreliable and in general a poor basis on which to make predictions. This initial paper rejects the statistical method as being an insufficient basis for making predictions and claims that it is incapable of logically supporting its conclusions. Although no evidence is provided to substantiate this claim, a number of scientific methods, both of historical and present day importance, are briefly reviewed with which one can contrast the statistical method.     

Reliability engineering concepts in design for usability

Engineering and managerial response to the increased demand for more usable computer products is hindered by lack of relevant knowledge in the majority of current Research and Development environments. This paper proposes to use reinterpretation of the existing reliability engineering knowledge base into the language of design for usability, as a way to speed up acceptance and adoption of human factors engineering tools, methods and expertise into the computer designers' set of core competencies. Described similarities in concepts, definitions, formal models and practical aspects between reliability and usability, justify this proposal.     

An explanation and critique of taguchi's contributions to quality engineering

Recently there has been much interest and some controversy concerning the statistical methods employed by Professor Genichi Taguchi of Japan for improving the quality of products and processes. These methods include the use of fractional factorial designs and other orthogonal arrays, parameter design to minimize sensitivity to environmental factors, parameter design for minimizing transmitted variation, signal-to-noise ratios, loss functions, accumulation analysis, minute analysis and the analysis of life test data. This paper explains some of Taguchi's contributions to quality engineering and also provides a critical evaluation of his statistical methods. Our conclusion is that although on the one hand, Professor Taguchi's quality engineering ideas are of great importance and should become part of the working knowledge of every engineer, on the other hand, many of the techniques of statistical design and analysis he employs to put these ideas into practice are often inefficient and unnecessarily complicated and should be replaced or appropriately modified. In this short article only an overview is attempted, but references are appended where these matters are discussed in greater detail.     

Mixing Bayes and empirical Bayes inference to anticipate the realization of engineering concerns about variant system designs

Mixing Bayes and Empirical Bayes inference provides reliability estimates for variant system designs by using relevant failure data - observed and anticipated - about engineering changes arising due to modification and innovation. A coherent inference framework is proposed to predict the realization of engineering concerns during product development so that informed decisions can be made about the system design and the analysis conducted to prove reliability. The proposed method involves combining subjective prior distributions for the number of engineering concerns with empirical priors for the non-parametric distribution of time to realize these concerns in such a way that we can cross-tabulate classes of concerns to failure events within time partitions at an appropriate level of granularity. To support efficient implementation, a computationally convenient hypergeometric approximation is developed for the counting distributions appropriate to our underlying stochastic model. The accuracy of our approximation over first-order alternatives is examined, and demonstrated, through an evaluation experiment. An industrial application illustrates model implementation and shows how estimates can be updated using information arising during development test and analysis.     

High Reliability Organization Research: A Literature Review for Health Care

Abstract

High reliability organizations (HROs) operate in hazardous, fast-paced, and complex environments yet avoid catastrophic accidents. Since the genesis of HRO theory in 1989, interest in HROs has grown beyond hazardous operations to many industries, including health care. This article reviews the literature to determine the extent to which changes made in health care organizations are aligned with HRO theory, and more specifically, with Roberts’ Six Actions, which are based on HRO theory. The results suggest that HRO theory remains of interest to health care organizations. Implications for engineering managers and opportunities for future research are suggested.     

高性能磁流变液研究的进展

本文综述了近年来在高性能磁流变液的合成制备、性能表征和工程应用等方面国内外开展的研究工作,并对高性能磁流变液在可靠性方面的发展趋势进行了阐述。     

The role of quality engineering in the 1990s

The business environment of the 1990s will be affected in a major way by two major catalysts for change: one driven by technology and one driven by organizational change. This paper reviews the impact of major catalysts for change expected in the 1990s. Organizational change strategies will enable a corporation to be able accurately to assess the performance and success of each engineering group in the design, manufacturing, and customer installation and life cycle support. The strategies for the development of the methods and tools and long-term career development strategies to support the ability of the organization to catalyse change are also discussed, with the conclusion that the quality engineering profession, correctly structured and empowered, will be the driver of the successful implementation of organizational change strategies in the 1990s.     

Analysis of human error in nursing care

Analysis of reports about incidental and accidental events in nursing care were made using a reliability engineering method. Unnatural working hours, such as evening duty, night duty falling next to a holiday, two consecutive night-duty shifts, and two consecutive evening-duty shifts were major factors in the occurrence of errors. In a mixed-division ward (a ward containing patients belonging to different divisions), rule-based errors happened more frequently than in a single-division ward. Also, less experienced nursing staffs made errors more frequently than experienced nursing staffs.     

Reliability engineering: Old problems and new challenges

The first recorded usage of the word reliability dates back to the 1800s, albeit referred to a person and not a technical system. Since then, the concept of reliability has become a pervasive attribute worth of both qualitative and quantitative connotations. In particular, the revolutionary social, cultural and technological changes that have occurred from the 1800s to the 2000s have contributed to the need for a rational framework and quantitative treatment of the reliability of engineered systems and plants. This has led to the rise of reliability engineering as a scientific discipline.In this paper, some considerations are shared with respect to a number of problems and challenges which researchers and practitioners in reliability engineering are facing when analyzing today's complex systems. The focus will be on the contribution of reliability to system safety and on its role within system risk analysis.     

Meeting the challenges related to material issues in chemical industries

Reliable performance and profitability are two important requirements for any chemical industry. In order to achieve high level of reliability and excellent performance, several issues related to design, materials selection, fabrication, quality assurance, transport, storage, inputs from condition monitoring, failure analysis etc. have to be adequately addressed and implemented. Technology related to nondestructive testing and monitoring of the plant is also essential for precise identification of defect sites and to take appropriate remedial decision regarding repair, replacement or modification of process conditions. The interdisciplinary holistic approach enhances the life of critical engineering components in chemical plants. Further, understanding the failure modes of the components through the analysis of failed components throws light on the choice of appropriate preventive measures to be taken well in advance, to have a control over the overall health of the plant. The failure analysis also leads to better design modification and condition monitoring methodologies, for the next generation components and plants. At the Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam, a unique combination of the expertise in design, materials selection, fabrication, NDT development, condition monitoring, life prediction and failure analysis exists to obtain desired results for achieving high levels of reliability and performance assessment of critical engineering components in chemical industries. Case studies related to design, materials selection and fabrication aspects of critical components in nuclear fuel reprocessing plants, NDT development and condition monitoring of various components of nuclear power plants, and important failure investigations on critical engineering components in chemical and allied industries are discussed in this paper. Future directions are identified and planned approaches are briefly described     

Extended block diagram method for a multi-state system reliability assessment

The presented method extends the classical reliability block diagram method to a repairable multi-state system. It is very suitable for engineering applications since the procedure is well formalized and based on the natural decomposition of the entire multi-state system (the system is represented as a collection of its elements). Until now, the classical block diagram method did not provide the reliability assessment for the repairable multi-state system. The straightforward stochastic process methods are very difficult for engineering application in such cases due to the “dimension damnation”—huge number of system states. The suggested method is based on the combined random processes and the universal generating function technique and drastically reduces the number of states in the multi-state model.     

Reliability of fiber-reinforced composite laminate plates

Many engineering structures ranging from aircrafts, spacecrafts and submarines to civil structures, automobiles, trucks and rail vehicles, require less weight and more stiff and strong materials. As a result of these requirements, the use of composite materials has increased during the past decades. In fact during the past five years, we have witnessed exponential growth in research and field demonstrations of fiber-reinforced composites in civil engineering. Manufacturers and designers have now access to a wide range of composite materials. However, they face great problems with forecasting the reliability of composites materials. Due to the differences among the properties of materials used for composites, manufacturing processes, load combinations, and types of environment, the prediction of reliability of composites is a very complex task. In this study, the reliability of fiber-reinforced composite laminate plates under random loads is investigated. The background of the problem is defined, the failure criterion chosen is presented, and the probability of failure is computed by Monte Carlo simulation.     

Event oriented system analysis

This article presents an attempt towards a probabilistic event oriented system analysis in engineering. Engineering systems are represented as either complete or incomplete systems of events and as compounds of various subsystems of events. The event oriented system analysis investigates important subsystems in engineering systems, such as operational modes and failure modes and their interrelations. The analysis is also applicable to engineering systems with various relations among the sets of events, such as mutually exclusive and inclusive sets. Further, the systems and subsystems are subjected to probability and uncertainty analysis. The system uncertainty analysis is based on entropy. General relations among the probability, uncertainty of the system and uncertainties of the subsystems are derived by using information theory. Specific mathematical aspects and available methods in the uncertainty modelling of systems and subsystems are summarised. Numerical examples confirm the relevance of the event oriented system analysis and indicate potential improvements in system design.