A model for co-evolution in manufacturing based on biological analogy

Manufacturing systems continue to adapt in order to survive the changing and challenging markets and global competition. Product and manufacturing design and capabilities are configured to allow the needed adaptation through innovative design, improved system paradigms, intelligent design and optimisation models, and product grouping to increase efficiency. In this research, it is hypothesised that the evolution and co-evolution of products and the machines used to manufacture them is akin to that observed in the adaptation of biological species. The symbiosis between products and manufacturing capabilities is studied using real examples, and a new model that establishes the symbiotic relationship between their evolution paths and observed co-evolution trends based on available historical information is proposed. Dual cladograms are used to track their evolution and detect useful potential development and plausible future evolution trends. When a state of co-evolution equilibrium is reached, a stimulus for more abrupt changes would be needed to cause further evolution on both sides. The co-evolution model has been applied to an example based on analysing the history of machine tools development and data from a major machine tools manufacturer. The evolution and co-evolution hypotheses of machined parts and machine tools were charted up to the currently observed state of equilibrium in this application field. This innovative model of co-evolution in manufacturing can help improve the utility of manufacturing resources and prolong the life of manufacturing systems beyond a single product generation and its variants.     

Fuzzy logic based leanness assessment and its decision support system

Manufacturing organisations have been witnessing a transition from mass manufacturing to lean manufacturing. Lean manufacturing is focused on the elimination of obvious wastes occurring in the manufacturing process, thereby enabling cost reduction. The quantification of leanness is one of the contemporary research agendas of lean manufacturing. This paper reports a study which is carried out to assess the leanness level of a manufacturing organisation. During this research study, a leanness measurement model has been designed. Then the leanness index has been computed. Since the manual computation is time consuming and error-prone, a computerised decision support system has been developed. This decision support system has been designated as FLBLA-DSS (decision support system for fuzzy logic based leanness assessment). FLBLA-DSS computes the fuzzy leanness index, Euclidean distance and identifies the weaker areas which need improvement. The developed DSS has been test implemented in an Indian modular switches manufacturing organisation.     

Leanness assessment using multi-grade fuzzy approach

The manufacturing organisations have been witnessing a transition from mass manufacturing to lean manufacturing. Lean operations are characterised by the elimination of obvious wastes occurring in the manufacturing process, thereby facilitating cost reduction. This paper reports a research carried out to assess the leanness of an organisation using multi-grade fuzzy approach. During this research, a leanness measurement model incorporated with multi-grade fuzzy approach was designed. This is followed by the substitution of the data gathered from a manufacturing organisation. After the computation of leanness index, the areas for leanness improvement have been identified. The approach contributed in this project could be used as a test kit for periodically evaluating an organisation's leanness.     

Multimode machine tools—a concept that improves operations of flexible manufacturing systems

Modern flexible manufacturing systems offer certain benefits when compared to conventional stand-alone systems, but have problems associated with high capital outlays, system integration difficulties and lower than expected utilization because of characteristics of their component machine tools. These problems are addressed in this paper, which introduces a conceptual computer controlled multimode machine tool that can be programmed to execute conventional machining operations. Characteristics of hypothetical manufacturing systems built with these machines, are compared to those of conventional flexible manufacturing systems using established criteria, where it it is shown that these multimode machine tools enhance the operation of flexible manufacturing systems.     

Simulation in the design and operation of manufacturing systems: state of the art and new trends

As the industrial requirements change at a rapid pace due to the drastic evolution of technology, the necessity of quickly investigating potential system alternatives towards a more efficient manufacturing system design arises more intensely than ever. Manufacturing systems simulation has proven to be a powerful tool for designing and evaluating a manufacturing system due to its low cost, quick analysis, low risk and meaningful insight that it may provide, improving thus the understanding of the influence of each component. Simulation comprises an indispensable set of IT tools and methods for the successful implementation of digital manufacturing. It allows experimentation and validation of product, process, and system design and configuration. This paper investigates the major historical milestones in the evolution of manufacturing systems simulation technologies and examines recent industrial and research approaches in key fields of manufacturing. It describes how the urge towards digitalisation of manufacturing in the context of the 4th Industrial revolution has shaped simulation in the design and operation of manufacturing systems and reviews the new approaches that have arisen in the literature. Particular focus is given to technologies in the digitalised factories of the future that are gaining ground in industrial applications simulation, offering multiple advantages.     

A polychromatic sets approach to the conceptual design of machine tools

Currently very few computer-aided conceptual design systems are available to support the initial development of a machine tool and its structure (concept, calculation, design) and the verification of the prototype. In recent years, polychromatic sets have emerged as a promising approach for mathematical modelling. The theory, techniques, and approaches of polychromatic sets are capable of playing an important role in the conceptual design of a variety of products including machine tools. In this paper, the concept of polychromatic sets is introduced, and a polychromatic sets approach for the conceptual design of machine tools is proposed. The usefulness of the proposed method is illustrated by a conceptual design example of a machining centre of drilling, milling, and boring. Applying the proposed approach to machine tools helps to make right decisions in the conceptual design stage. Due to its powerful mathematical modelling capability, the polychromatic sets technique proposed in this paper may possibly be extended and applied to design evaluation problems encountered in other design tasks in manufacturing systems including process planning.     

Managing lean manufacturing in material handling operations

The problem addressed by this research is to implement lean manufacturing in a material handling system of a petroleum drill bit manufacturing company. Lean manufacturing has been mandated by higher level management as a tool to be used in waste reduction. Operational group must define the objectives of lean manufacturing and deploy the tools to specific work cells. A methodology that provides operational group with a tool to assist in defining the objectives of lean manufacturing is developed. A case study is used to demonstrate the lean implementation in material handling operations.     

Proposition of a model for measuring adherence to lean practices: applied to Turkish automotive part suppliers

The objective of this study is to develop a model for measuring adherence to lean practices for automotive part suppliers and to assess the relationship between the firm performance and the adoption of lean principles. This model has been developed by utilising the lean practices defined in the literature. The proposed model has been successfully applied to a large number of automotive part suppliers, and has been tested for its statistical validity. To test the proposed model, data were obtained from 207 automotive part suppliers by using the Computer-aided Telephone Interview method. Validity and reliability tests of the developed model of leanness are realised through exploratory and confirmatory factor analyses. Correlation analyses are used to examine the relationships between the lean applications and company performance and size. Analysis of Variance (ANOVA) is applied to reveal whether there are differences in the use of lean techniques across different company categories. The study shows that, in general, Turkish automotive part suppliers are performing their internal production in compliance with the lean manufacturing principles. Furthermore, it is found that there is a significant relationship between adaptation of lean principles by the supplier firms and their performance. The proposed model of leanness can be used by companies in the automotive industry to measure their leanness levels.     

A Multilevel Framework for Lean Product Development System Design

Abstract:

Organizations today face intense and growing pressure to reduce cost, decrease time to market, and maximize stakeholder value in product development (PD). Many organizations have adopted lean product development (LPD) methods in an attempt to improve their PD systems; however, despite two decades of research, there is still much less understanding of the characteristics of effective LPD systems than of effective lean manufacturing systems. LPD systems are complex systems involving multiple organizational levels; however, most LPD research to date has focused only on a single level. There is currently a lack of understanding of the interactions between levels and effective means for managing these interactions. In this article, we propose a multilevel framework designed to capture key LPD system principles at the functional, project, and portfolio levels; tools and practices for implementing principles at each level; and approaches for managing the interactions between levels. A longitudinal case study is used to expand and refine a conceptual framework developed through literature review. Future research should focus on further validating the framework and applying the framework to improve LPD system design.     

新型陶瓷快速成型装置数控系统的研究

基于GT400运动控制器的开放式体系结构的数控系统软硬件平台及其关键技术,研究陶瓷零件快速成型设备数控系统对于缩短陶瓷零件的制造周期以及提高企业的生产效率所具有的重要意义.阐述了陶瓷零件快速成型机的新工艺方法和特点,对新型陶瓷零件快速成型机机械系统及其控制要求作了详细分析,着重介绍了陶瓷零件快速成型机控制系统的硬件设计及自顶向下的软件设计.利用Visual C++6.0开发工具和GT系列运动控制器自带的DLL动态链接库开发了操作方便、运行稳定、加工精度高的开放式陶瓷快速成型装置数控系统.控制系统能够很好地满足系统开放性的要求及产品自动化生产的要求,提高了经济效益.     

Lean,agile or leagile? Matching your supply chain to the marketplace

Many enterprises have pursued the lean thinking paradigm to improve the efficiency of their business processes. More recently, the agile manufacturing paradigm has been highlighted as an alternative to, and possibly an improvement on, leanness. In pursuing such arguments in isolation, the power of each paradigm may be lost, which is basically that agile manufacturing is adopted where demand is volatile, and lean manufacturing adopted where there is a stable demand. However, in some situations it is advisable to utilize a different paradigm on either side of the material flow de-coupling point to enable a total supply chain strategy. This approach we have termed the Leagile Paradigm. This paper therefore considers the effect of the marketplace environment on strategy selection to ensure optimal supply chain performance. Real-world case studies in the mechanical precision products, carpet making, and electronic products market sectors demonstrate the new approach to matching supply chain design to the actual needs of the marketplace.     

Improved performance evaluation of tool condition identification by manufacturing loss consideration

When neural networks are used to identify tool states in machining processes, the main interest is often the recognition ability. It is usually believed that a higher classification rate from pattern recognition can improve the accuracy and reliability of tool condition monitoring, thereby reducing the manufacturing loss. Nevertheless, the two objectives are not identical in most practical manufacturing systems. The aim is to address this issue and propose a new performance evaluation function so that the recognition ability of tool condition monitoring can be evaluated more reasonably. On this basis, two kinds of manufacturing loss due to misclassification are analysed: the over-prediction caused by misclassifying the worn tool condition; and the under-prediction caused by misclassifying the fresh tool condition. By using both to calculate corresponding weights in the performance evaluation function, the potential manufacturing loss is introduced to evaluate the recognition performance of tool condition monitoring. Based on this performance evaluation function, a modified support vector machine approach with two regularization parameters is employed to learn the information of every tool state. In this support vector machine design, the effective feature set extracted from acoustic emission signals is used as inputs, and a five-fold cross-validation is used to tune the parameters. The experimental results show that the proposed method can reliably identify tool flank wear and reduce the overdue prediction of worn tool conditions and its relative loss. Experimental results show that this approach may effectively identify tool state over a range of cutting conditions and reduce the manufacturing loss in the practical industry process.     

Towards new architectures of machine tools

This paper presents new possibilities of machine tool architecture and a methodological approach to the design of these machines. The method proposed deals with the evolution of machine tool towards flexibility, automatic control and integration in flexible ceils. Each machine tool is composed of basic modules and each of them is linked with manufacturing features defined with the workpieces to be machined. Expert rules and algorithms based on temporal logic are used to optimize this architecture. The link with control unit design is made with a view of zits integration with the whole machine. In order to specify the quality of machine flexibility, the entropy system has been defined.     

Design of a tool management system in a flexible cell

In this work we describe the design of a tool management system of a flexible manufacturing facility operating in the avionics components industry, The design included several modifications to the existing system. While previously the tool handling devices were used only to perform machine setup, the modifications allowed the tools to be shared among machines. This allowed a full exploitation of the flexibility of the system. In the work we thoroughly report on the procedures implemented for the determination of tools to be duplicated, for part routeing and scheduling, and for tool movements synchronization.     

Scalable reconfigurable equipment design principles

Scalability is one of six key characteristics found in reconfigurable manufacturing systems. Scalable systems satisfy changing capacity requirements efficiently through system reconfiguration, and in the flexible manufacturing literature this capability is called expansion flexibility. The development of modular scalable machine tools is a necessary precursor to achieving scalable systems. Unfortunately, there is little work describing the design of scalable machines. This paper establishes the need for scalable machines and a basis for evaluating and describing them. Applicable metrics are defined, and an architecture for scalable machines is presented. Two examples illustrate the scalable architecture. Finally, a design parameter based on a mathematical approach is presented to determine the optimal number of modules to be included on a modular scalable machine. This as a design parameter is important because it limits machine size and the number of module interfaces included in the base machine structure.     

Criteria for a lean organisation: development of a lean assessment tool

Lean principles have long been recognised as a competitive advantage. Although there are several measures for various aspects of lean production in the literature, there is no comprehensive measure for overall lean implementation in business firms. An appropriate measurement tool is needed to assess the effectiveness and efficiency of the lean implementation throughout the entire organisation. Based on lean research, a comprehensive tool called the leanness assessment tool (LAT) is developed, using both quantitative (directly measurable and objective) and qualitative (perceptions of individuals) approaches to assess lean implementation. The LAT measures leanness using eight quantitative performance dimensions: time effectiveness, quality, process, cost, human resources, delivery, customer and inventory. The LAT also uses five qualitative performance dimensions: quality, process, customer, human resources and delivery, with 51 evaluation items. The fuzzy method allows managers to identify improvement needs in lean implementation, and the use of radar charts allows an immediate, comprehensive view of strong areas and those needing improvement. Practical uses of the LAT are discussed in the conclusion, along with possible limitations.     

Enhancement of accuracy of multi-axis machine tools through error measurement and compensation of errors using laser interferometry technique

The present era is witnessing advancement in digital electronics and microprocessor which enables manufacturing sector capable to produce complex components within small tolerance zone in the tune of nanometre and at one machining center. All motion control systems have some form of position feed back system fitted with the machine. Such systems are not generally accurate due to the errors in the positioning performance of the machine tool which will change over time to time due to wear, damage and environmental effects. The complex structure of multi-axis CNC machine tools produce an inaccuracy at the tool tip caused by kinematic parameter deviations resulting in manufacturing errors, assembly errors or quasi-static errors. Analysis of these errors using a laser measurement system provides the manufacturers a way to achieve better accuracy and hence higher quality output from these processes. In this communication, techniques to measure the linear positional errors of axes of CNC machine tools by a laser interferometer calibration system and accuracy enhancement using the data obtained from the calibration cycle by feeding into the machine’s controller with the help of linear error compensation package are discussed.     

Lean Implementation and Organizational Transformation: A Literature Review

Manufacturing organizations are constantly striving to develop more effective and flexible means for managing challenges due to globalization and increasing customer expectations. This has led to increased efforts by the business community to research and implement the Toyota Production System, or lean manufacturing, to address these challenges. These efforts have resulted in numerous publications on lean manufacturing, including research reports, scholarly articles, and trade magazine articles. However, the existing body of knowledge on lean manufacturing is disperse and diverse in nature with respect to the application and implementation of lean tools and practices, making it difficult for researchers and practitioners to gain a real grasp of this topic. In this article, we have comprehensively organized the existing work on implementation of lean manufacturing in a more structured way, enabling engineering management practitioners to more easily identify knowledge and best practices and enabling researchers to identify gaps in the extant literature. Lastly, drawing from the organizational science literature, this article also provides important insights on lean manufacturing from the perspective of organizational learning, innovation, and \culture.     

Ultrasonic on-machine measurement for internal topographies

The integration of metrology into the manufacturing process is becoming increasingly important for production technology. The measurement directly on machine tools is especially improving manufacturing strategies. So far, optical or tactile measuring systems are the state-of-the-art for dimensional measurements in process metrology. However, the wall thickness of structures with inner cavities cannot be measured with these systems. Owing to these deficits, an ultrasonic system was integrated into the peripheral equipment of a machine tool. Both the extensive signal processing of the acoustic echoes and the developed software tool ' w -sonic' are discussed. The aim is to show the potential of the ultrasonic in-line measurement. A practical application for the individual machining of gas cylinders and initial results are also presented.