Mapping quality assurance systems: A methodology

This paper reports on a method (quality management activity planning—Q-MAP) for mapping quality assurance procedures, information flows and responsibilities. A comparison is made of the ICAM definition (IDEF) method and Q-MAP as to their suitability for mapping quality assurance systems and fostering the advancement of the quality improvement process. The achievements arising from the use of Q-MAP at Garrett Automotive Limited are examined. It is pointed out that the involvement of employees in the preparation of Q-MAP diagrams has led to improvements in processes and procedures by eliminating differences between actual and documented work practices and that a wider cross-section of employees are now familiar with the company's quality assurance system.     

Quality assurance of welds in ship structures

This paper describes procedures for predicting the growth rate of fatigue cracks in ship structure welds under sea-wave loading as well as the stress corrosion cracking behaviour of steel in marine structures. A computer program which can be applied to assess the residual life-time and to estimate the probability of failure of marine structures under wave action is presented. The main objective of applying this program is the development of an optimal inspection and maintenance policy for marine structures. Moreover, the presented computer program is of value to insurance companies in order to assess the safety level of a marine structure and consequently to estimate their financial risk.     

Design of an integrated quality assurance strategy in production systems

High-quality of products is a critical issue for manufacturers to maintain their competitiveness in global markets. For this reason, more attention has been paid by operations managers and academics to the design of quality assurance strategies, acceptance sampling plans and inspection allocation problems. In the last decades, international research has studied and introduced several models and approaches to investigate these issues. The purpose of this paper is to provide a new methodology for designing and selecting correct integrated quality assurance strategies, defining cost models for acceptance policies and inspection station configurations. Generally, high-quality of items is guaranteed by avoiding defects, mainly caused by non-conforming components, resulting from instantaneous and standard infant mortality. Thus, an optimal acceptance policy is defined in order to reduce the instantaneous infant mortality defects. A closed-form equation has been introduced to determine easily and quickly the optimal percentage of checked items. Furthermore, a more convenient inspection station configuration is determined in order to minimise the expected total cost, composed of testing, inspection and penalty cost elements. The innovative concept of defect rate as an inspection time variable dependent has been introduced. The impact of different economic and survival parameters on designing inspection policies is also investigated. Finally, a real-life case study demonstrates the applicability of this methodology in real production systems and several considerations are reported about the future research, that the authors will carry out.     

Performance measurement for a manufacturing system based on quality,cost and time

Product quality, manufacturing cost and manufacturing time are three of the major concerns in a manufacturing system. This study proposes a product capability index to evaluate the quality of a multi-process product and addresses the relationship between process yield and the product capability index. In addition, this paper develops a time–cost index to assess manufacturing cost and manufacturing time. The quality index and time–cost index are simultaneously used to monitor product quality and manufacturing time on a quality and time–cost analysis chart. The quality and time–cost analysis chart, providing accurate information on the quality status and time–cost status for each process, helps to initiate, effectively and efficiently, quality improvement plans to elevate product quality and manufacturing time and manufacturing cost control for a manufacturing system.     

改进的质量功能配置在质量成本优化分析上的应用

在改进型的质量功能配置工具中,增加了质量保证成本和质量损失成本两个主要的评价指标,修正了市场竞争评价指数和技术竞争评价指数,并引入了层次分析法,对定性决策因素给以定量的测度权重.根据质量保证成本与技术重要度的关系,以及质量损失成本对质量需求的影响,提出了适合设计阶段的质量成本优化分析方法.最后的应用结果表明,利用改进型的质量功能配置工具进行质量成本分析是有效的.     

Integrating failure analysis and risk analysis with quality assurance in the design phase of medical product development

Today, manufacturing operates as a global network, which has created more awareness of the quality of products and services. A systematic and rational way of managing quality assurance is currently lacking. This can cause serious problems in sectors such as the medical industry, as product failure may not only cause time delays, but also create risks for the health and safety of patients and users. This paper proposes a quality assurance approach that incorporates risk analysis (based on ISO14971) and failure analysis (based on FMEA) into the product design phase to assure product quality in the short term and facilitate global manufacturing practices in the long run. The proposed approach includes a Markov model to predict product failure from a customer perspective, which serves as a checkpoint for feedback to provide a basis for quality assurance. A medical equipment firm is used as a test-bed to illustrate how the proposed approach works and to verify its effectiveness.     

Cultural heritage in project management: project appraisal and quality assurance in the early phase of major public investments

This paper is an analysis of how cultural heritage values are handled in documentation related to early phase evaluations of major public investment projects in Norway. This study was instigated by an apparent lack in the consideration of cultural heritage values in such documentation. We conducted a case study document analysis to see how cultural heritage issues are addressed in the early phases of projects. Methodologically, the paper analyses the use of vocabulary related to cultural heritage values in the documentation. There is uniform documentation available from these projects. The results suggest that cultural heritage values are mentioned but seldom substantially discussed in the documents. Cultural heritage values tend to be discussed using non-specific language. There is an emphasis on legislation regarding cultural heritage and how the legislation can be a problem. Today’s discussion of cultural heritage values appears to be lacking and in need of a strengthened framework. The methodology applied in this study aims to provide a structured search method for the unstructured discussion of cultural heritage issues in these extensive documents.     

Reliability analysis for mechanical parts considering hidden cost via the modified quality loss model

The improvement of mechanical parts inherent reliability has an impact on the reputation and performance of the company. To estimate the inherent reliability of products more conveniently and economically, a hidden quality cost-production cost (HQC-PC) reliability prediction model is put forward. To estimate the hidden quality cost (HQC) of products more accurately, a quadratic exponential quality loss function model is established, which is different from Taguchi's quadratic quality loss function (QLF) and the modified QLFs. In the new quality loss model, the growth rate of quality loss on both sides of the target value is considered. Under the condition that the quality characteristic value obeys normal distribution, the general estimation formulas of HQC in the tolerance range is obtained considering sampling error and the numerical model of inherent reliability is established. The effect of different parameters on the inherent reliability of products is discussed with practical case, such as design and production parameters. Then, the appropriate process capability index (PCI) is selected according to different production processes. The relationship between the HQC-PC reliability prediction model and PCI is derived by a numerical model of inherent reliability. A new analysis method of inherent reliability is proposed.     

Inspection procedures in manufacturing processes: recent studies and research perspectives

Quality inspections are performed in almost every production system to prevent nonconforming products from reaching final customers or end users. Quality inspections are typically performed referring to specific inspection procedures, depending on the production process. Two general inspection paradigms may be identified: online inspection and offline inspection. These are differentiated by the way in which inspections are made. The paper presents a recent survey on new studies on inspection procedures for both paradigms. The main novelty of the study is the identification of new research perspectives in such a highly explored field. New schemes of analysis allow highlighting the research areas which are not adequately covered by the literature. A brief examination of some bibliometric aspects is also proposed.     

Lean manufacturing tool in engineer-to-order environment: Project cost deployment

The present paper proposes a modified version of the Manufacturing cost deployment (MCD) method to analyse engineer-to-order (ETO) production systems. The novel approach, named Project cost deployment (PCD), introduces two substantial and innovative modifications. To begin with, the concept of manual assembly macro-activity replaces the traditional concept of station. Then, a brand-new structure for classifying and analysing losses is introduced, that is specifically defined to deal with the inefficiencies of the manual assembly tasks. The validity of the approach is proved by a real-world industrial application. The obtained results demonstrate that the PCD method allows the analyst to identify the hidden losses and to quantify the wastes from an economical point of view. In addition, PCD permits to estimate the impacts of potential (lean) improvement activities and projects in terms of both efficiency and effectiveness.     

Benefit-based cost allocation for residentially distributed photovoltaic systems in China: A cooperative game theory approach

Distributed photovoltaic (PV) systems have constantly been the key to achieve a low-carbon economy in China. However, the development of Chinese distributed PV systems has failed to meet expectations because of their irrational profit and cost allocations. In this study, the methodology for calculating the levelized cost of energy (LCOE) for PV is thoroughly discussed to address this issue. A mixed-integer linear programming model is built to determine the optimal system operation strategy with a benefit analysis. An externality-corrected mathematical model based on Shapley value is established to allocate the cost of distributed PV systems in 15 Chinese cities between the government, utility grid and residents. Results show that (i) an inverse relationship exists between the LCOEs and solar radiation levels; (ii) the government and residents gain extra benefits from the utility grid through net metering policies, and the utility grid should be the highly subsidized participant; (iii) the percentage of cost assigned to the utility grid and government should increase with the expansion of battery bank to weaken the impact of demand response on increasing theoretical subsidies; and (iv) apart from the LCOE, the local residential electricity prices remarkably impact the subsidy calculation results.     

High shear wet granulation: Improved understanding of the effects of process variables on granule and tablet properties of a high-dose,high-hydrophobicity API based on quality by design and multivariate analysis approaches

High shear wet granulation (HSWG), as a widely used granulation technology, has been studied extensively. However, for the HSWG of formulations containing hydrophobic components, the influence of process variables on the properties of granules and tablets has not been reported. In the present study, based on a combination of quality by design and multivariate analysis (MVA) approaches, quercetin with high-dose and high-hydrophobicity was used to study the relationship between process variables, granule properties, and tablet properties in HSWG systematically. Control and response variables were determined using risk assessment. The optimal fitting empirical models established by Box-Behnken design showed that the liquid to solid ratio and impeller speed were the most important factors, which affected all product properties except Carr’s index and yield pressure. Instead, the influence of wet massing time was relatively small (only the effects on yield, granule size, granule hardness, and compression ratio were significant). Then, the process design space was obtained by limiting the related critical quality attributes, which was verified effectively. Scanning electron microscope images showed that smooth granules were produced using higher process parameters, whereas rough and porous granules resulted at lower process parameters. Furthermore, the MVA results demonstrated that increasing the granule hardness led to an increase in the compression ratio and a decrease in tensile strength of the tablets. Tablet fragility and disintegration time were mainly affected by granule density and bulk density, respectively, and both were negatively correlated. The established research paradigm is not only conducive to the successful development of quercetin products, but also provides valuable guidance for improving HSWG–based product development with such formulation characteristics.     

Uncovering differences and similarities among quality function deployment-based methods in Design for X: Benchmarking in different domains

The ability for a product or a service to meet customer needs and requirements efficiently before its market launch is a key-point in design and development activities. Quality Function Deployment (QFD) represents one of the most powerful design methods to achieve such a goal. This study investigates the QFD-based methods proposed in the last two decades, whose use in different ambits of Design for X (DfX) is reported to be effective. We selected most common QFD-based methods, analyzing how designers can implement and coordinate them in design activities effectively throughout their application to an identical case study.     

Taguchi methods in practice: An analysis of Goh's paradox

The background of ‘Goh's paradox’ in connection with the application of the common version of Genichi Taguchi's parameter design routine is examined. A detailed case study is used to show how the paradox can be resolved, as well as to assess the probability of success of marginal analysis in Taguchi's prescribed procedure for quality and reliability improvement.     

Risk Failure Deployment: A novel integrated tool to prioritize corrective actions in failure mode and effects analysis

In this paper, a novel integrated tool for failure mode and effects analysis (FMEA), opportunely named Risk Failure Deployment (RFD), which is able to evaluate the most critical failure modes and provide analyst with a practical and step-by-step guidance by selecting the most effective corrective actions for removal/mitigation process of root causes, is presented. Thanks to the modification of the framework of the Manufacturing cost deployment (MCD) and to its well-structured use of matrices, the novel RFD is able both to handle the dependencies and interactions between different and numerous failures and to evaluate the most critical ones on the basis of the risk priority number (RPN). Thereafter, the logical relationship between root causes and failure modes is assessed. Successively, the prioritization of corrective actions that are the most suitable for root causes is executed using not only the RPN but also other criteria, such as the economic aspect and the ease of implementation, that are unavoidable to execute a rational and effective selection of improvement activities. The effectiveness and usefulness in practice of the original tool for the prioritization of corrective actions to mitigate the risks due to failure modes collected during FMEA are presented in a case study.