Development and evaluation of a tree-indexing approach to improve case-based reasoning: illustrated using the due date assignment problem

In this study a novel case indexing approach is proposed for case-based reasoning (CBR). This new approach, called the tree-indexing approach, is a modified form of the inductive learning-indexing (IL-indexing) approach and is especially applied to assist CBR in numeric prediction. The tree-indexing approach organizes the cases in the memory by inducting a tree-shaped structure, in order to improve the efficiency and effectiveness of case retrieval. The experiments, using three real world problems from the UCI repository, show that the CBR with the tree-indexing approach (T-CBR) is superior to the conventional CBR. This study also applies T-CBR for solving the due date assignment problem in a dynamic job shop environment in order to investigate whether T-CBR's expected benefits can be observed in practice. The results of the experiments show that our proposed T-CBR can indeed more accurately predict the job due date than the other methods presently in use.     

面向现代制造的先进测试技术及其发展趋势

先进测试技术与仪器对于现代制造系统的发展具有重要支撑作用。在分析现代制造系统与先进测试技术同步发展特征的基础上,探讨现代制造系统与先进测试技术相互关系和协同发展的问题,分析论述了现代制造系统中的精密测试、在线检测、数字化测试、计算机视觉测试、三坐标测试机等关键技术的应用和发展概况,介绍了在工业机器人视觉检测、超声波在线探伤系统以及基于Web的智能远程无损评估系统等方面的研究工作成果。针对先进测试技术的研究要紧紧围绕现代制造业的发展需要,分析论述了先进测试技术领域的一些值得关注、重点研究和应用的技术发展方向。     

Synchronization in manufacturing systems: quantification and relation to logistics performance

The term ‘synchronization’ in manufacturing refers to the provision of the right components to the subsequent production steps at the right moment in time. It is widely assumed that synchronization is beneficial to the logistics performance of manufacturing systems. However, it has been shown that synchronization phenomena can be detrimental to systems in which they emerge. To study if synchronization phenomena also occur in and affect manufacturing systems’ performance, a formal quantification and holistic understanding of the types of synchronization phenomena emerging in manufacturing are needed. This article aims to fill this research gap by developing synchronization measures for manufacturing systems, applying these measures to real-world production feedback data and utilising them to test the assumption about synchronization’s beneficial effect on logistics performance. We identify two distinct synchronization types occurring in manufacturing systems, logistics and physics synchronization, and show that they are negatively correlated. Further, we show that logistics synchronization and due date performance exhibit anti-correlation and thus question the assumption that synchronization leads to higher efficiency in manufacturing systems. This article aids production managers in designing and optimising production systems, and supports further empirical research in production planning and control and production system design.     

A double-layered optimisation approach for the integrated due date assignment and scheduling problem

As the market competition becomes fiercer, contemporary make-to-order firms are confronted with both due date quotation and production scheduling problems at the same time. On the one hand, in order to attract customers, the firm needs to quote a short lead time; on the other hand, once a due date has been promised, the firm must spare no effort to deliver the goods no later than this date. If due date assignment and shop scheduling are processed separately by two systems, the overall performance is unlikely to be satisfactory because the two tasks are actually interrelated (e.g. a tighter due date setting will increase the chances of tardiness despite its appeal for the incoming customer). Therefore, we consider the problem by integrating due date assignment and shop scheduling into one optimisation model. A double-layered heuristic optimisation algorithm is presented for solving this problem. In the upper-layer genetic algorithm which performs coarse-granularity optimisation, Bayesian networks are used to learn the distribution of optimal due date values. As the second-layer algorithm, a parameter perturbation method is applied for a finer-granularity neighbourhood search. Computational experiments prove the efficacy and efficiency of the proposed algorithm.     

Capacity allocation problem in flexible manufacturing systems: branch and bound based approaches

This study considers an operation assignment and capacity allocation problem that arises in flexible manufacturing systems. The machines have limited time and tool magazine capacities and the available tools are limited. Our objective is to maximise total weight of assigned operations. We develop a branch and bound algorithm that finds the optimal solutions and a beam search algorithm that finds high quality solutions in polynomial time.     

Photoelastic analysis of stress waves in building subjected to vertical impact under laboratory earthquake experiments

In an earthquake occurring directly under a city, the vertical impact induced from the source may cause a large amount of damage to a column and beam of the building. Model-based simulations are carried out with photoelastic material in order to examine the effect of a vertical impact on the building in the case of a near-field type earthquake. The dynamic photoelastic method combined with strain gages is utilized to conduct direct full field and real time observations of stress waves in a building due to vertical impact in laboratory earthquake experiments. The conditions under which vertical impact loading is applied to the model building in a controlled laboratory environment are derived from the data recorded for the 1995 Hanshin-Awaji earthquake in Japan. The experimental apparatus with which an impact of a longitudinal stress pulse is able to be applied to a model of a real building is shown. It is estimated from our earthquake simulations that large dynamic stress concentrations are produced in the beam–column joints of the building by the vertical impact arising from a seismic source located directly below a surface.     

Product and process innovation in manufacturing firms: a 30-year bibliometric analysis

In recent decades, internationalization of research activities has increased, as demonstrated by the phenomena of international scientific collaboration and international mobility of researchers. This paper investigates whether the international scientific collaboration is explained by researchers’ motivation as well as their international migration. Using metadata from papers published in Nature and Science from 1989 to 2009, count data estimation was conducted. The results illustrate those researchers’ international migration and motivation, shown by both synergy and difference effects between countries, explain international collaboration. This implies that international co-authorship in recent decades has been based on researchers’ motivation as well as their networking. The positive result for synergy effects also means that pairs of countries with rich research environments tended to have more international collaboration, which may lead to the convergence of qualified research output in advanced scientific countries. Our findings also support the conclusion that researchers move to countries with better research environments, but networks created through international collaboration are not a factor in international migration. The relationship between international mobility and collaboration is confirmed as going in one direction, from mobility to collaboration.     

Product platforms design,selection and customisation in high-variety manufacturing

Product platforms represent an effective strategy implemented by manufacturers to cope with dynamic market demands, decrease lead-time and delay products differentiation. A decision support system (DSS) for product platforms design and selection in high-variety manufacturing is presented. It applies median-joining phylogenetic networks (MJPN) for the platforms design and phylogenetic tree decomposition for platforms selection by determining the product family phylogenetic network and defines the platforms at various levels of assembly corresponding to different trade-offs between number of platforms (variety) and number of assembly/disassembly tasks (customisation effort). Product platforms are reconfigured and customised to derive final product variants. The phylogenetic tree is decomposed in multiple levels, from the native platforms to the final variants. New Platforms Reconfiguration Index (PRI) and Platforms Customisation Index (PCI) were developed as metrics to evaluate the platforms customisation effort. A case study of a large family of plastic valves is used to demonstrate the DSS application. It shows reduction of 60% in platforms variety and increases in platform customisation assembly/disassembly tasks by only 20% leading to significant production and inventory efficiencies and cost savings. This methodology supports companies in the design and selection of best product platforms for high-variety to reduce cost and delivery time.     

On the combined effect of due date setting,order release,and output control: an assessment by simulation

Workload Control is a production control concept for high-variety shops built on the principle of input/output control. The literature, however, has argued that input/output control overemphasises throughput improvements to the detriment of the timing of individual orders and, consequently, that it needs to be supplemented by a preceding customer enquiry stage where due dates are set. Yet, although there are broad separate literature streams on due date setting, order release, and output control, there is a lack of research on the three functions together. In response, this study uses simulation to assess the combined performance effect of all three functions. Results show that each control function can be related to a specific performance objective. The degree of emphasis that should be placed on each function, therefore, depends on a company’s specific performance needs. Due date setting and capacity adjustments (output control) are shown to support each other as they address different performance objectives. Meanwhile, order release (input control) is effective in reducing work-in-process and can play a role in making throughput improvements when capacity adjustments are not possible. Findings enhance existing literature on the diagnosis of delivery reliability performance in high-variety shops, with important implications for research and practice.     

Product design and development in small firms

Some of the problems experienced by small firms engaged in product design and development activities are examined. After a review of recent published material, a case history is presented which analyses a UK based small firm. In the discussion which completes the paper, areas for further research are indicated.     

Relationship between employee involvement and lean manufacturing and its effect on performance in a rigid continuous process industry

This research aims to empirically test the effect of employee involvement on lean manufacturing (LM), and the effect of LM on production outcomes. Employee involvement is operationalised through four related variables: empowerment, training, contingent remuneration and communication. The effects are tested by recording management perceptions in a different industrial sector from those usually studied in previous research – ceramic manufacturers, a highly competitive and internationally successful sector. We obtained data from 101 ceramic tile plants (64% of response rate) in the Valencia region of Spain. This approach is developed using a statistical method called partial least squares. All paths are significant except for contingent remuneration; specifically, relationships were found between empowerment, training, communication and LM, and between LM and performance.     

The impact of quality practices and employee empowerment in the performance of hospital units

Healthcare is a unique services environment with increasing demand for services coupled with widely diverse patient needs. In addition, hospitals are under increased pressure to provide quality care yet simultaneously decrease associated costs. This study examines how the use of quality practices and employee empowerment impact hospital unit outcomes. Specifically, the sociotechnical theory is used to explain the relationship of quality practices and employee empowerment in respiratory care services. Utilising data from 101 different hospital units, survey responses from managers and physicians within the same hospital units are used to test the impact on quality and cost of care performance metrics via path modelling. The results show the social side of improvement programs, i.e. employee empowerment, may be a critical component to true quality improvement in hospital units. Furthermore, while respiratory care managers feel that employee empowerment reduces costs of patient care, physicians felt that there was no impact on costs. The implications of these findings and differing perspectives are discussed.     

Implementation of Industry 4.0 and lean production in Brazilian manufacturing companies

The adoption of Industry 4.0 technologies has been deemed as a strategy to increase product quality and make manufacturing processes more efficient. However, the way that these technologies are integrated into existing production systems and which processes they can support is still under investigation. Thus, this paper aims to examine the relationship between lean production (LP) practices and the implementation of Industry 4.0 in Brazilian manufacturing companies. To achieve that we use data from a survey carried out with 110 companies of different sizes and sectors, at different stages of LP implementation. Data collected were analysed by means of multivariate analysis. Our findings indicate that LP practices are positively associated with Industry 4.0 technologies and their concurrent implementation leads to larger performance improvements. Further, the contextual variables investigated do matter to this association, although not all aspects matter to the same extent and effect.     

An impact of manufacturing flexibility and technological dimensions of manufacturing strategy on improving supply chain responsiveness: Business environment perspective

The main objective of this research is to investigate the impact of manufacturing flexibility and technological dimensions of manufacturing strategy on responsiveness in the supply chain. Based on the theoretical background of dynamic capability, this study also examines the role of the business environment on the relationship between manufacturing flexibility and supply chain responsiveness. 144 structured surveys were collected and the partial least squares of structural equation modelling approach were utilised for data analysis. The result establishes relationships among various dimensions of manufacturing flexibility. Although the technological dimensions in manufacturing strategy of such advanced manufacturing technology (AMT) and e-procurement do not have any direct impact on new product and market flexibility, they increase supply chain responsiveness, which helps to react quickly against supply chain disruptions. More importantly, the business environment has a moderating effect on the relationship between market flexibility and supply chain responsiveness.     

Informing additive manufacturing technology adoption: total cost and the impact of capacity utilisation

Informing Additive Manufacturing (AM) technology adoption decisions, this paper investigates the relationship between build volume capacity utilisation and efficient technology operation in an inter-process comparison of the costs of manufacturing a complex component used in the packaging industry. Confronting the reported costs of a conventional machining and welding pathway with an estimator of the costs incurred through an AM route utilising Direct Metal Laser Sintering (DMLS), we weave together four aspects: optimised capacity utilisation, ancillary process steps, the effect of build failure and design adaptation. Recognising that AM users can fill unused machine capacity with other, potentially unrelated, geometries, we posit a characteristic of ‘fungible’ build capacity. This aspect is integrated in the cost estimation framework through computational build volume packing, drawing on a basket of sample geometries. We show that the unit cost in mixed builds at full capacity is lower than in builds limited to a single type of geometry; in our study, this results in a mean unit cost overstatement of 157%. The estimated manufacturing cost savings from AM adoption range from 36 to 46%. Additionally, we indicate that operating cost savings resulting from design adaptation are likely to far outweigh the manufacturing cost advantage.     

Measurement of fracture initiation toughness and crack resistance in instrumented Charpy impact testing

A new method has been developed involving direct measurement of the load-line displacement during instrumented Charpy testing. The method uses a laser interferometer to measure displacement in addition to the load-line displacement derived from the load signal. Tests were conducted using fatigue precracked and V-notched test pieces in the temperature range +23°C to −80°C on a conventional ship grade steel, a pressure vessel steel and two welded joints. Good correlation was found between the J_0.2 initiation fracture toughness determined by the multi-specimen method and the J_i fracture toughness determined from single specimens using the new method to detect ductile fracture initiation.     

Product/process definition,technology adoption and workforce qualification: impact on performance

This paper analyses the impact of manufacturing technologies (MTs) and workers’ qualifications on labour productivity and flexibility, taking into account the product-process (P-P) strategy adopted by the company. This allows for a discussion about the well-known P-P matrix initially proposed by Hayes and Wheelwright (1994) in order to evaluate options of production systems. The empirical analysis is performed by means of a panel of data of 13 years for the Spanish manufacturing industry, which includes a total of 7741 observations. The results indicate a complementary effect between technology and skills to overcome the trade-offs of production systems.     

The performance of Due Date setting rules in assembly and multi-stage job shops: an assessment by simulation

Setting short yet reliable Due Dates (DDs) is an important early production planning and control task. The majority of job-shop research on DD setting assumes simple product structures without assembly operations. However, in practice, product structures are often complex, and multiple final assembly operations may be required. This paper evaluates the performance of DD setting rules in the context of complex product structures, considering two scenarios: two-level assembly job shops, where orders converge on one final assembly operation; and two-level multi-stage job shops, where a series of assembly operations are undertaken. New rules are proposed which are substantially simpler and more suitable for practical use than those in the literature. These rules are only outperformed by a more sophisticated rule from the wider literature, newly introduced into the context of assembly and multi-stage job shops. Which rule to apply in practice depends on whether a manager considers the improvement in performance more important than the loss of simplicity. Future research should investigate how jobs can be planned and controlled effectively when some or all DDs are set externally by customers rather than internally using a DD setting rule.     

Effectiveness in social impact assessment: Aboriginal peoples and resource development in Australia

Definitions of and judgments regarding effectiveness in social impact assessment (SIA) depend on how the purposes of SIA are understood. They are defined differently by various interests that participate in, or are affected by, impact assessment processes, and the concept of ‘effectiveness’ and the issue of what is required to achieve it are both contested and contextual. This article reviews a number of different approaches to SIA and outlines what effectiveness might mean for each. It then considers, at two levels, what ‘effective SIA’ involves in the context of large-scale resource development on Aboriginal land in Australia. The first level involves control of SIA. For indigenous peoples who have historically been excluded from and ignored by SIAs undertaken as part of government approval processes, Aboriginal control is an essential prerequisite for ‘effective SIA’. However, control only creates the potential for effectiveness. The second level of analysis involves the practical activities that must be undertaken, and issues that must be addressed, to realize this potential. The author develops a matrix designed to help identify and manage these activities and issues in a systematic way.