Minimizing rework costs in multistage production processes by modifying quality specification limits

© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksMultistage production processes are becoming more important in the industry to ensure levels of flexibility, efficiency and modularity. Thus, the way in which companies define optimal production parameters related to production costs and quality must be adapted to this reality. In this paper we introduce a multi-response optimization (MRO) model for a two stage production process. The model gives first stage quality specification limits which minimize the rework costs caused by the nonconforming parts of the whole process. The proposed model is applied to an example based on a production process of the automotive industry. The benefits of the model are evaluated by comparing the capability and the rework costs of the multistage production process before and after the optimization.Peer ReviewedPostprint (published version

Monitoring high complex production processes using process capability indices

The increasing demand and the globalization of the market are leading to increasing levels of quality in production processes, and thus, nowadays, multiple product characteristics must be tested because they are considered critical. In this context, decision makers are forced to interpret a huge amount of quality indicators, when monitoring production processes. This fact leads to a misunderstanding as a result of information overload. The aim of this paper is to help practitioners when monitoring the capability of processes with a huge amount of product characteristics. We propose a methodology that reduces the amount of data in capability analysis by structuring hierarchically the multiple quality indicators obtained in the quality tests. The proposed methodology may help practitioners and decision makers of the industry in three aspects of statistical process monitoring: to identify the part of a complex production process that presents capability problems, to detect worsening over the time in multivariate production processes, and to compare similar production processes. Some illustrative examples based on different kinds of production processes are discussed in order to illustrate the methodology. A case of study based on a real production process of the automotive industry is analyzed using the proposed methodology. We conclude that the proposed methodology reduces the necessary amount of data in capability analysis; and thus, that it provides an added value of great interest for managers and decision makers.Postprint (published version

Why Non-accelerated Filers Voluntarily Comply with SOX 404b?

This paper investigates the managers’ incentives to voluntarily comply with SOX 404b and the determinants of firms who voluntarily disclose SOX 404b internal control over financial reporting assessment. We find that voluntary SOX 404b reporting non-accelerated filers are more likely to receive effective internal control over financial reporting opinion than accelerated filers and large accelerated filers. We find that voluntary SOX 404b reporting non-accelerated filers are more likely to hire Big Four as independent auditors than non-SOX 404b reporting non-accelerated filers. We also predict and found substantially sufficient cases where non-accelerated filers which used to be, or ex-post became accelerated filers or large accelerated filers, and non-accelerated filers with parent companies complying with SOX 404b are motivated to voluntarily comply with SOX 404b

Commitment and Dispatch of Heat and Power Units via Affinely Adjustable Robust Optimization

The joint management of heat and power systems is believed to be key to the integration of renewables into energy systems with a large penetration of district heating. Determining the day-ahead unit commitment and production schedules for these systems is an optimization problem subject to uncertainty stemming from the unpredictability of demand and prices for heat and electricity. Furthermore, owing to the dynamic features of production and heat storage units as well as to the length and granularity of the optimization horizon (e.g., one whole day with hourly resolution), this problem is in essence a multi-stage one. We propose a formulation based on robust optimization where recourse decisions are approximated as linear or piecewise-linear functions of the uncertain parameters. This approach allows for a rigorous modeling of the uncertainty in multi-stage decision-making without compromising computational tractability. We perform an extensive numerical study based on data from the Copenhagen area in Denmark, which highlights important features of the proposed model. Firstly, we illustrate commitment and dispatch choices that increase conservativeness in the robust optimization approach. Secondly, we appraise the gain obtained by switching from linear to piecewise-linear decision rules within robust optimization. Furthermore, we give directions for selecting the parameters defining the uncertainty set (size, budget) and assess the resulting trade-off between average profit and conservativeness of the solution. Finally, we perform a thorough comparison with competing models based on deterministic optimization and stochastic programming.Comment: 31 page

The Influence of Internal Drivers and Environmental Drivers towards Supply Chain Management (SCM) Strategy, SCM Practices, Responsiveness and Implication on the Operational Performance of Organic Fertilizer Manufacturers in East Java, Indonesia

The aim of this research is to formulate a theoretical model that explains causal links among supply chain drivers and operational performance by adding several SCM variables, namely strategy, practices and responsiveness into the links and empirically tests the model on organic fertilizer manufacturers in East Java, Indonesia. Provincial sample data that consist of 85 companies are analyzed using SEM by component-based approach, which is Generalized Structured Component Analysis (GSCA). The result shows that internal drivers only have weak influence to the operational performance and environmental drivers do not influence it. Furthermore, SCM practice do not influence the operational performance. Nevertheless, the relationships between other variables hypothesized are found positively and significantly influence the operational performance. In order to compete in supply chain level, companies have to adopt the right SCM strategy and also build supply chain responsiveness. Both have important role as intervening variables to strengthen the weak or insignificant relationships. This research implication might limited for the types of industry in which the Government plays big role as one of the environmental drivers. The organic fertilizer industry has to compete with chemical fertilizer products which have won the customer’s loyalty; and therefore the organic fertilizer manufacturers have to change their SCM strategy to become more responsive to the customers’ needs and requirements, also internally improving innovation aspect, particularly product innovation. The integration drivers are not directly related to performance, but rather have to be through SCM practices. Likewise, the SCM practices are not directly related to performance, but rather have to be through responsiveness. These research findings strengthen the strategic supply chain theory and the supply chain responsiveness theory. Keywords: supply chain drivers, SCM strategy, SCM practices, responsiveness, operational performance, organic fertilizer manufacturers

Validation and Improvement of the European Customer Satisfaction Index for the Spanish Wine Sector

Purpose: A study of the Spanish wine sector, in this case specifically the Designation of Origin (DO) Somontano, requires validation of the European Customer Satisfaction Index (ECSI), which also needs to be improved and adapted to obtain more information on customer satisfaction. Design/methodology/approach: Applying the ECSI model, based on structural equation modeling (SEM) using partial least squares (PLS). Findings: An empirical analysis shows that the importance of customers’ expectations and perceived quality are the most influential factors in achieving satisfaction. Also highlighted in the new model is the linkage between service and product qualities in a unique variable, total quality. Originality/value: In addition to validating the ECSI model for DO Somontano, a new innovative implementation was developed and tested to improve the calculation of satisfaction

TQM Extension Practices and Performance: A Case Study in Malaysian Aerospace Industry

This research examines the implementation of total quality management (TQM) extension practices and business performance using a case study on Malaysian aerospace industries. The study examines the organization effectiveness and efficiencies, and the level of company performance that complies with the international quality standard, role and regulation of the aerospace authority. Malaysian aerospace industries are expected to expand and significantly contribute to capture value-added high technology, national economic growth, and increasing challenge in a globalization competition marketplace which is expected to become fierce in the year 2015 and beyond. The main objective of this research is to investigate and measure ten variables of TQM, which are leadership, policy and strategy, people and result, partnership and resources, processes quality management, information and analysis, society result, human resources focused,customer satisfaction and requirement. This research also examines the company performance using the criteria of performance excellence such as MBNQA, EFQM, AS/EN9100, AQS D1-9000, National Institute Standard and Technology (NIST),International Aerospace Group of Quality (IAQG), International Aerospace Quality Standard (IAQS), Business Excellent Models (BEM) and others. The result of the reliability test i.e. the Cronbach’s Alpha was extremely reliable. Similarly, the model was accepted and significantly fit. It was found that the variables were significantly associated with the underlying latent variable which measured a total of 81% .The variance was explained by extraction factor sums squared loadings of the information yielded in business performance of Malaysian aerospace firms. The main findings showed that all the two (2) variables i.e. leadership and partnership resources are less influence the business performance of Malaysian aerospace industry. Therefore, it is suggested that firms need to formulate corrective action plans and continuous quality improvements to achieve excellence. Therefore, the following recommendations are identified: (1) improvement of internal and external partnerships, design, product, processes, quality,services, on time delivery; and (2) improvement of employee education, training and development; and focus on qualifying and certifying both personnel and facilities to the customer requirement needed and role regulatory of the international authority aerospace requirement. Consequently, these enable the Malaysian aerospace firms to secure long term contracts, gain trust from partners, have timely payments, ensure the suppliers and customers’ satisfaction, increase the performance level, get new investments from foreign customers, and do business globally. The novelty of this study are the understanding the excellent level of capability of business performance; realized the actual quality practices which have significant effect towards business performance; including the necessary improvements to be carried-out by the companies involved