In grinding SKD-11 hardened steel, the martensite phase transformation is the results of the thermo-mechanical coupled effect and the grind-hardening is highly dependent on the grinding parameters. Special attention is paid to indicating formation mechanism of dark-etching layer and the transition layer to get the desirable hardened surface.
This paper describes the use of Schonberger's 16 customer-focused principles as an assessment tool to compare and contrast four manufacturing sites within the same organisation. The major objective is to examine the extent to which the tool has industry and/or cultural bias and this is achieved by comparisons between plants manufacturing the same products in Australia and another country (either Thailand or China) and also between plants manufacturing different but related products in the same geographical area (Australia and the Far East). It provides a critical assessment of the utility of the Schonberger model as a consultancy tool and as a model for research of this nature and concludes that the tool is very useful in this context, although care is required in the use of the scoring system: there is some bias towards batch manufacturing and larger companies but very little cultural bias.
Currently, manufacturing enterprise integration is mainly conducted using proprietary approaches, which are expensive and time-consuming, resulting in the integrated manufacturing systems with a little business agility. Well-defined and consistent frameworks for integrating a variety of disparate and heterogeneous applications on the shop floor to enable essential business agility to meet the needs of next generation manufacturing are in great demand. This paper presents a service-oriented integration framework for facilitating system integration in an automated semiconductor manufacturing environment. By taking advantage of the advances of open computing service architecture and networked computing technologies, the proposed integration framework aims to provide an integrated automated Semiconductor Manufacturing System (SMS) increased productivity, efficiency and business agility. In the framework, manufacturing processes defined as production services in a Virtual Production Line (VPL) can be dynamically added, adjusted or removed. Moreover, production services can be remotely controlled, monitored and inspected in a timely manner. The results of this research arose out of the successful implementation of enterprise-wide manufacturing process control and recipe management in a small-scale back-end SMS.
This paper compares the results of surveys conducted in 1989 and 1996 that examined the planning and implementation activities associated with investments in Advanced Manufacturing Technology (AMT) in British manufacturing companies. The same data collection instrument was used in both surveys which focused on a number of aspects of the AMT planning and implementation process. The similarities and differences identified in respect of motivation for investing in AMTs, role of respondents in strategy formulation, nature and size of AMT investments made, sources of information used, financial evaluation carried out, training in AMT and production management, benefits of AMTs, and risks and difficulties associated with adopting AMTs are discussed. Conclusions and implications for management are presented.
The period 1960-1993 was an intensive learning period for Directors, Managers and Engineers in Western manufacturing businesses as the competitive power of the Toyota Production System started to wreak havoc in their market places. Following this period, a more intelligent appreciation has emerged of the underlying elements which must be integrated to create a competitive manufacturing business. New breeds of Strategic Business Manager and Business Systems Engineer now exist in industry, capable of selecting and applying the necessary interlocking building blocks of new forms of modular team organisation and the supporting methodologies, tools and techniques, within a value-adding strategy framework. This modern modular approach is described in an introductory way and will be useful to intelligent young managers who wish to avoid the commoditisation and crude cost-cutting methods of their predecessors. Full application of the proven approach described leads to the healthy development of short, medium and long-term economic value-added growth so essential to long term business survival.
This paper is directed toward the development of models, methods and tools suitable for effective, profitable, and autonomous cellular manufacturing as a new vision for the 21st Century. Cellular manufacturing is mainly concerned with the efficient integration of three major concerns: (1) planning-oriented predictive cellular layout design; (2) an unexpected order-adapted cellular manufacturing through the integration between manufacturing decision processes and cellular layout, and (3) a contingency-driving shop floor adaptation for supporting continuous improvement. The possibility of sudden large changes in demand rate and process route is greatly reduced by both the detailed analysis of decision processes and the reconfiguration of existing facilities through workers' high skills. To increase the ability of reaction to shop floor contingencies, real-time information on the conditions of the shop floor will be analysed to support continuous improvements for sustaining superior performances in unexpected changes. The continuous improvements support the user with five modules real-time status monitoring, real data analysis and forecasts renewal, diagnosis through intelligent decision support system, simulation optimisation, and results evaluation and performance measurement.
This paper summarises the economic performance of China since the launch of economic reform and its opening up to the outside world. It presents an analysis of the macro-economy and enterprise system related to the strengths and weaknesses of technology management in China. A case study, which is the result of an international joint research project is presented, and shows the interaction between enterprises and technology support institutions. Finally, a theoretical explanation of institutionalism and the system concept of management are summed up.
Manufacturing in the early decades of the 21st Century will reflect continuation of trends and developments in the last quarter of the 20th Century. The accumulated effects of those trends will alter many aspects of manufacturing. For example, the increasing role of information technology will affect the manufacturing system from vendors and suppliers through production and on to delivery to customers and consumers, and waste disposal. Social forces, such as the environmental movement through pressures for recycling, reclamation and remanufacturing, will affect the choice of materials, design for dismantlement, and manufacturing for maintenance and repair. New tools and factors will come into play using micromachines in the early decades of the 21st Century. There may even be practical nanomachines. The vast new developments created by molecular genetics will develop new markets for manufacturing. Virtual reality design, test and evaluation will improve the quality of all products.
Optimal machining parameters (spindle speed, feed rate, and depth of cut) are crucial to high-performance CNC pocketing and profiling, which is concerned with shorter machining time, higher surface quality, and longer tool life. However, the feed rates are often conservatively fixed, obviously un-optimised, for different geometries of a curved profile. In this work, an intelligent approach to determining non-constant feed rates is proposed. First, the geometric features of this profile are identified, and the corresponding effective radial depths of cut are calculated. Second, based on a database of these machining parameters, a fuzzy rule-based system is established to predict various cutting forces along this profile. Then the feed rates are adjusted so that the cutting forces always remain high and chatter is still prevented. Thus the high-performance machining can be realised by using this approach, which can also be readily implemented in production process planning to benefit the manufacturing industry.
Pulsed Nd:YAG laser beam is widely applied in micro-machining with different micro-scale geometries on engineering materials such as ceramics, composites, and diamond. The present research papers deals with the Response Surface Methodology (RSM) based mathematical modelling and analysis on machining characteristics of pulsed Nd:YAG laser during micro-grooving operation on flat surface of aluminium titanate. An attempt has been made to optimise laser parametric setting for achieving accurate taper angles of micro-grooves. Based on the modelling and parametric optimisation analysis, the optimal laser process parametric setting has been obtained as air pressure of 0.9 kg/cm², lamp current of 20.4 amp, pulse frequency of 2.8 kHz, pulse width of 2.7% of duty cycle and cutting speed 10 mm/s for achieving the optimum taper angle of 11.1°.
Silicon wafers are the primary semiconductor substrates used to fabricate Integrated Circuits (ICs). Recently, the industry is making a transition from 200 to 300 mm wafers. To attain very flat 300 mm silicon wafers, grinding has been used to flatten the wire-sawn wafers. However, it is challenging for grinding to remove the waviness induced in wire sawing. To enhance the waviness removal ability of grinding process, several approaches have been explored including soft-pad grinding. This paper presents a study on soft-pad grinding of 300 mm wire-sawn silicon wafers through Finite Element Analysis (FEA) with designed experiments. A 25 (five factors, two levels) full factorial design is employed to reveal the main effects as well as the interaction effects of five factors (elastic modulus, Poisson’s ratio and thickness of the soft pad; waviness wavelength and waviness height of silicon wafers) on the effectiveness of waviness removal. FEA simulation results are compared with relevant experimental results. Implications of this study to manufacturing are also discussed.
Drilling of Ti-6Al-4V with Supernitride coated carbide tool gave better performance in term of tool life compared to TiAlN coated carbide tool. The use of 25 m/min cutting speed shows improvement in tool life performance. Non-uniform flank wear, excessive chipping and micro-cracking were the dominant tool failure modes under most tested conditions. Adhesion, attrition and diffusion were the operating wear mechanism on both tools when drilling Ti-6Al-4V.
The general aim of this research is to introduce the traditional manufacturing strategy theory to the emerging research field on manufacturing networks. More specifically, the purpose is to examine the link between the competitive priorities of a firm and the way in which it chooses to organise its manufacturing network. This paper analyses the present literature on manufacturing networks, taking a manufacturing strategy perspective. The study identifies linkages between competitive priorities, network focus, and the manufacturing management within the network. The theory suggests that there should be typical differences between how companies organise their manufacturing networks, depending on which priorities are regarded as the most important. However, the six case companies analysed show that there are successful companies that manage and organise their networks in ways that the literature on the subject does not account for. Suggestions for future research on manufacturing networks are based on these findings.
This is a case study on the concurrent engineering experience of Boeing 777. A new generation of aircraft was designed, developed and inducted in a record time. A variety of new technological and organisational enablers have been used to reduce costs and cycle time: horizontal coordination, clever and innovative use of existing and new designs and technologies, digital product definition, systems integration, and working together teams that included customer airlines and suppliers. Top management provided the necessary support.
One of the principal concerns with ISO 9000 is its inability to document and monitor continuous improvement. QS-9000 has recognised this weakness and incorporates and demands a comprehensive philosophy of continuous improvement in all areas related to quality. As QS-9000 is relatively new for all companies, whether auditing or implementing, little experience is available for individuals to be confident that any new method of working is acceptable. Given that QS-9000 does not accept minor noncompliance as ISO 9000 does, there is a risk that major changes to the detail of its manufacturing processes may have far reaching implications for gaining or maintaining QS-9000. This paper addresses some of the major concerns, when implementing new technologies within the QS-9000 framework, and how the detail of a new technology, superabrasive reaming, may relate to individual aspects of the standard.
Abrasive flow machining (AFM) is a non-traditional process used to de-burr, radius, polish and remove recast layers of the components in a wide range of applications. The material removal in abrasive flow machining takes place by flowing the media, mixed with abrasives, across the surface to be machined. The media is the key element in the process because of its ability to precisely abrade the selected areas along its flow path. From the review of literature, it was found that there is a need to know the viscosity of the media, since it has a significant effect on the process performance parameters. In the present work, a viscometer set-up has been fabricated based on the principle of visco-elasticity. The creep compliance and the bulk modulus have been determined and the viscosity of the abrasive media has been subsequently calculated. Measurements have been conducted for obtaining viscosity along with an assessment of specimen length and initial load, the influence of reduced data points and the repeatability of the experiments. Besides this, experiments have been conducted at varying concentration and temperature of the abrasive media. Experiments show that the viscosity of the media increases with the percentage concentration of abrasives and decreases with temperature. Viscosities at different concentration of the abrasives were compared with the values obtained from a capillary viscometer and the comparison was found to be good.
In this paper, a simplified model for predicting the penetration rate of Abrasive Water Jets (AWJs) in a piercing operation is presented. It proposes the use of a lumped mass approach for the jet combined with Bitter's theory of erosion for interpreting the material removal associated with the piercing process. The lumped mass approach considers the jet as a series of cylindrical slugs penetrating into the material and Bitter's theory of erosion predicts the cutting mechanism associated with jet penetration. By balancing the momentum of any cylindrical slug with drag forces exerted on it by the outgoing slurry, the geometry of the jet profile is predicted. The jet profile is then used to interpret the geometry of the pierced hole. The rate of material removal is used to predict the variation of depth of the pierced hole with time. Finally, the results predicted with the theoretical model are validated with experimental data (Hashish, 1996).
Magnetorheological Abrasive Flow Finishing (MRAFF) is developed for finishing complex internal geometries up to nanometer level using Magnetorheological polishing (MRP) fluid which comprises of MR-fluid with fine abrasive particles dispersed in it. Experiments were conducted on stainless steel and silicon nitride workpieces using silicon carbide, boron carbide and diamond abrasives. The best surface finish obtained on the stainless steel workpieces with the present set-up configuration is 30 nm. The effect of number of finishing cycles, extrusion pressure and magnetic flux density is studied on change in surface roughness (Ra) value. Capillary magnetorheometer is designed and fabricated for rheological characterisation of MR-polishing fluid. Bingham plastic, Herschel Bulkley and Casson's fluid model are used to fit the obtained data points.
As finishing techniques for Si wafers, the free abrasive processes like lapping and polishing are able to offer a better surface roughness when finer abrasives are applied, but fall short of maintaining profile accuracy when the wafer size increases. On the other hand, the fixed abrasive process or grinding is known as a promising solution to improve accuracy of profile geometry, but always introduces subsurface damages. In order to simultaneously achieve both surface quality and geometry accuracy, this research has proposed a novel chemo-mechanical-grinding (CMG) process by effective use of chemical reaction in the grinding process. CMG wheels which contain chemically active abrasives and additives have been developed, characterised and applied into grinding of ø300 mm bare Si wafers. The ground wafers are examined on both surface and subsurface. The results show no subsurface damage produced due to machining. A defect-free surface so far only achievable by polishing has been realised by the fixed abrasive process. A discussion is also made to understand the mechanism and chemical reaction involved in the process.
Abrasive Flow Machining (AFM) is a non-conventional finishing process that deburrs and polishes by forcing an abrasive media across the work piece surface. One serious limitation of this process is its low productivity in terms of improvement in surface roughness. In recent years, hybrid-machining processes have been developed to improve the efficiency of such processes. This paper discusses improved fixturing as a technique for productivity enhancement in terms of surface roughness (Ra). A rotating Centrifugal Force Generating (CFG) rod was used inside the cylindrical work piece, which provides the centrifugal force to the abrasive particles normal to the axis of work piece. The effect of the key parameters on the performance of process has been studied. The results show that for a given improvement in Ra value the processing time can be reduced. It is seen that the significant process parameters are rpm of CFG rod, extrusion pressure and abrasive mesh size.
After preliminary experimentation, a detailed study through statistical design of experiments was conducted for nanofinishing of stainless steel workpieces through Magnetorheological Abrasive Flow Finishing (MRAFF) process. Response surface regression analysis was done to analyse the effect of number of finishing cycles, extrusion pressure and magnetic flux density on percent change in surface roughness. 'F' test from the Analysis of Variance (ANOVA) was conducted and contribution of each model term in affecting percent improvement in surface finish was calculated. The experimental results were discussed and optimum finishing conditions were identified through contour plot. The best surface finish obtained on the stainless steel workpieces with the present set-up configuration is 30 nm.
Accelerated growth is the driving force of many technology intensive entrepreneurial companies throughout the world. In fact, fast growing companies drive new job creation and economic development in the regions and countries where they are located. However, accelerated growth may become uncontrolled growth and create major business, organisational and personal problems for the company, entrepreneurs, and managers. In some cases, it may even lead to collapse and bankruptcy. Thus, the challenge to both entrepreneurs and economic development organisations is not to stifle growth, but to manage growth, and, if possible, optimise growth. This paper discusses the three stages of growth of a new venture, and the psychological and business-related factors leading to uncontrolled growth. In order to manage growth, it is necessary to understand that growth does not occur according to a linear, smooth evolutionary pattern, but rather through alternate periods of evolution and revolution punctuated by crises. Each revolutionary period breeds the next crisis, and solution of the crisis generates the next period of evolutionary growth. The various stages of evolution are described, and guidelines offered on how management can anticipate and control the ensuing revolutionary crises. Finally, two examples of accelerated growth are discussed as case histories, taken from experience at Rensselaer Polytechnic Institute.
Competition in consumer product space demands acceleration of product development. Not only is greater variety demanded by customers, but every model seems destined to a shorter shelf life. Beyond this, the faster pace of regulatory changes adds even greater emphasis. To achieve more rapid product development, organisations have employed many fundamental enablers including: platform concepts allowing more effective leverage of designs; doing work concurrently; reducing the time taken for each task. Major automobile manufacturers have used all these methods for reducing product development time. Tata Motors, the largest automobile firm in India, has also used many of these same levers to accelerate product development. Tata Motors developed a new Sedan Indigo in about 20 months (and subsequently a Station-wagon, Indigo Marina), leveraging the successful Indica platform and manufacturing system. This approach, supported by a formal vehicle development process, concurrent engineering, maths based simulations and a disciplined manufacturing planning activity has been deployed with considerable benefit. The cross-functional teams employed in many stages of the development activity have also promoted organisational learning apart from reducing product development cycle time. Ultimately only the marketplace success of these products, contributing to the financial turnaround of the company, can be viewed as a true measure of the success of these efforts.
The present investigation is aimed to determine the effects of injection parameters on the dimensional accuracy of the wax patterns, produced by wax injection machine, to be used in ceramic shell investment casting process. The injection parameters viz. time, temperature, die temperature and holding time were considered. Experiments were performed and optimal parameters were determined. Linear and volumetric contractions of wax patterns were measured and dimensional variations were evaluated. Results reveal that an increase in injection temperature increases wax shrinkage, whereas increase in die temperature reduces the wax shrinkage. Slow injection and short holding time reduces dimensional variation in castings.
This empirical study investigates the simultaneous attainment of quality, cost and timing (QCT) in product development. The findings are based on a postal survey of 207 Japanese manufacturing companies listed on the Tokyo Stock Exchange Part I. Two subsystems of the target-costing system, named QFD and VE, are compared as the tools for handling QCT for both model change (MC) and entirely new (EN) products. We evaluated the combined effects of the variables on QCT performance through a variation of logistic regression of ordinal categorical variables, called the proportional odds model. Results show that the ways of improving the quality performance of MC or EN products at the highest level are different from the way of attaining QCT simultaneously. Again, the ways of improving the cost and timing performance at the highest level for both the products are the same as the way of furnishing the simultaneous achievement of QCT. The simultaneous attainment of QCT is possible if companies give priority to both quality and cost issues for fixing their targets, use QFD for determining cost improvement objects, and emphasise both mechanism and cost deployments for detecting bottlenecks. The findings suggest that QFD dominates over VE for both MC and EN products in achieving each of the QCT targets and even for their simultaneous attainment.
Manufacturing companies urgently need production systems that can provide both the flexibility to support product variety dynamically and the reconfigurability to be adapted economically to manufacture new products. In response to this need, a new collaborative automation paradigm is now emerging, which is characterised by decentralised distributed automation systems composed of intelligent reconfigurable mechatronics modules. This paper aims to provide a significant insight into the benefits and challenges posed by the industrial adoption of this paradigm. It describes both how best to provide appropriate modular reconfigurable automation systems and how best to implement engineering environments capable of supporting their lifecycle.
Product quality receives much attention but means different things to different people depending on their involvement with a product. Product Lifecycle Management (PLM) with its holistic view of a product from birth to death requires an equally encompassing view of quality. Product Lifecycle Quality (PLQ) is a proposed framework to define an overall view of product quality that applies to the four phases of a product's lifecycle: creation, build, use, and dispose. The paper will discuss product quality as being defined by the perceived value of the product user and propagating through the different phases of product's life.
High performance grinding implies in reliable monitoring at high speeds. In this paper, the development of a dressing monitoring system based on Artificial Intelligence (AI) is discussed. Different from previous works that adopt AI to classify Acoustic Emission (AE) measurements in grinding operations, the proposed approach is less sensitive to noise. The results point out to increases in production velocity and quality. Simulated tests indicate to the high performance of the monitoring even in noise conditions.
The roundness of a plunge ground cylindrical workpiece is a function of both the grinding wheel run-out and the waveshift. Waveshift determines how roundness profiles of the workpiece overlap in consecutive revolutions and is the difference between the ratio of the wheel rpm to the workpiece rpm and the next highest integer. In this paper, Acoustic Emission (AE) is evaluated as a possible method of monitoring wheel run-out, by measuring its amplitude at the wheel frequency. Variation of the AE signal at wheel frequency with waveshift is similar to model predictions of the variation in the normal force at wheel frequency and it reaches a maximum at a waveshift of 0.5. Tests to establish the linearity of the AE measurement with the amount of run-out show some scatter that needs to be understood before the technique can be successfully applied.
Grinding burn is a common phenomenon of thermal damage that has been one of the main constraints in grinding in respect of high efficiency and quality. Many attempts have tried to utilise Acoustic Emission (AE) technique for identifying grinding burn. However, the AE features of grinding burn are relatively weak and easily merged by other AE sources. This paper presents an investigation of the AE features in terms of grinding mechanical and thermal behaviour. A series tests of single grit scratching, tension testing and laser irradiation were carried out to simulate grinding process in order to separate the mechanical and thermal characteristics of grinding acoustic emission. By means of the Wavelet Packet Transform (WPT), AE features that represent grinding burn temperature can successfully be extracted. These AE footprint features can provide a firm foundation for monitoring and analysing grinding burn.
Acoustic monitoring is a popular tool for determining the working condition of a machine, thus allowing maintenance to be scheduled to minimise any process down time. Acoustic emission is generated by the frictional interaction of contacting asperities between two sliding surfaces in contact, which usually changes as machine components become worn. This paper presents the development of a probing system used to study the number of asperity contacts during sliding friction and give insight into the behaviour of two acoustic parameters, namely acoustic energy and count rate under different loading conditions.
Until very recently, GKN had but two core businesses, each with its own core technology. In both cases, the business had been built around technologies obtained externally - one through joint venture, the other by acquisition. In neither case, though, did the most senior management in GKN attach any particular importance to the technology the company was acquiring, many years passing before its significance began to seep through. These core businesses now provide most of GKN's profit. The case study shows the limitations of the static perspective normally adopted in the study of acquisition. Such a perspective focuses on the stock of resources and on how these may complement those of the acquirer. It pays less attention to what might develop in time, to the flow of resources. It seems to assume two separate tasks the mixing of two technologies followed by the development of the joint technology, the first to be accomplished to establish a new stock of resources before the second, the management of their flow, can be undertaken. This traditional approach may not be entirely appropriate to the study of acquisition in which technology is a major resource. A more dynamic approach in keeping with attitudes towards the management of technology is required both from managers and from those who study their behaviour.
An electromagnetically actuated flow control valve with meso scale was designed and fabricated with precision machining techniques. The electromagnetic force and the displacement of the actuator as well as the flow rate of the valve were studied in terms of operating currents. The non-linear regression equations, polynomial models, were employed to reveal the correlation among the electromagnetic force, the displacement and the applied current. Based on the Bernoulli equation and the principle of conservation of mass, the mathematical models were proposed to predict the characteristics of the flow control valve. The experimental results indicated that the larger the actuating current, the stronger the electromagnetic force. This electromagnetic force produced a larger displacement of the sliding spool of the valve. The flow rate of the fluid increased with the increasing driving current. The flow control valve was used to vary flow by changing the electrical current within the range of 30 to 80 mA. Results from the experimental data verified that the mathematical models were valid.
Automating manufacturing systems potentially improves competitiveness. Empirical studies show that the most successful result is achieved when decisions concerning automation are linked to the manufacturing strategies and competitive priorities of the company. It is suggested that automation is regarded as a separate decision group, within the manufacturing strategy content field.
Distributed manufacturing control systems, such as Holonic Control Systems (HCSs), are difficult to apprehend and to design, due to the presence of many autonomous, concurrent and asynchronous activities. A formal specification methodology allowing to understand, to synthesise the system specifications and to validate the correctness of their models would play a key role in its design and later in its implementation. This paper presents an approach to the formal specification of HCSs based on high-level Petri nets. The proposed approach is tested in the specification of the ADACOR HCS.
This paper proposes an approach for Small Manufacturing Enterprises (SMEs) to reinvent their manufacturing processes. Quality Function Deployment (QFD) as a best practice has been benefiting many leading manufacturers in Japan and the USA. However, there are still many SMEs, such as those in Hong Kong, having difficulty in adopting best practice to enhance their competitiveness in the world market. It is argued that organisational innovations could be made when a team of voluntary workers is assembled to share their experiences. It is understood that people involved may not be willing to work together due to conflicting interests. This paper articulates the key roles and activities for a successful industrial and academic collaboration to support action learning through QFD adaptation. Preliminary results indicate that this innovative approach has been validated with a case study in a local SME and it should be able to be replicated in another reference setting.
In this paper we share our experience in our involvement in the adaptation of Quality Function Deployment (QFD) in an SME in Hong Kong. The idea was put forward and initiated by the Manufacturing Department of our University and the Government Industrial Department. Due to disorientation of the management personnel regarding the costs and skills involved, the adaptation of QFD was partially discarded. Through a series of training workshops and statistical experiments, our team managed to establish a rapport with the Quality Assurance team in the company. Their confidence, awareness and skills were gradually built, statistical thinking was also fostered through collaboration. As a result the management was convinced and agreed to the full implementation of QFD.
In this paper, we discuss the development of a prototype DMN as a portal-based information exchange system for the design, manufacture and distribution of customised products for the watchmaking industry in Hong Kong. The e-portal serves as an enabling tool for the industry to share information instantly and globally among all the participants in the value chain and presents an unprecedented opportunity for a wider industrial collaboration among them. The portal offers flexibility to 'change by design' and creates distinctive knowledge for the channel partners in an industry characterised by a mature market. It allows them to address the challenges of fast response product development and manufacturing and hence better adapt to customer demands and coordinate go-to-market strategies in increasingly shorter time frames.
To respond to demands while reducing inventories, the Kanban control system (KCS) has been developed as a typical system for just-in-time production system. The original KCS has been revised to adaptive KCS by Tardif and Maaseidvaag (2001). However, in the adaptive KCS, how to adjust the number of Kanbans at each stage has never been considered. This paper proposes two types of adaptive KCS for two-stage production lines according to the difference of adjusting the number of Kanbans at each stage. A queuing-network model of the two types of adaptive KCSs is developed, and the performance is analysed and compared with each other by using Markov analysis. Numerical calculations are conducted to investigate the influence of the processing rate and cost parameters on the performance measures. The results show the advantages of each system over the other.
This paper presents a robust method for a class of non-linear proportional-integral-differential control systems to effectively utilise motion controllers. The model of a mixed type motion controller based on an industrial PC was proposed. The adaptive proportional integral derivative controllers using fuzzy logic can auto-tune the gains of them based on the speed error and its derivative, and it can offer a robust precision for a non-linear system. A simulation was carried out for controlling an uncertainly disturbed control system, and a case study was conducted based on the presented method to illustrate the effectiveness of the proposed controller.
Although cooperation is the fundamental characteristic of Virtual Enterprise (VE) concept, due to its distributed environment and the autonomous and heterogeneous nature of the VE members, cooperation can only be succeed if a proper management of dependencies between activities is in place. In this paper, we focus on negotiation process in VE formulation to clarify the effective VE management. Each enterprise in VE is defined as agent with multi utilities and a framework of multi-agent paradigm is newly proposed. We develop a computer simulation model, and clarify the supply chain formulation dynamism on the negotiation process with adaptive behaviour.
Subject of this contribution is to elaborate a methodological basis of reconfiguration for the collaborative networks (CN), which are characterised by high structure dynamics due to flexible customer-oriented networking of core competencies. Typical examples of such CN are networks of small and medium enterprises, supply chains with not-fixed supplier structures, and virtual enterprises. In such CN, reconfiguration challenges are caused by structure dynamics of both CN itself and of the supporting infrastructures like information processes. To answer these challenges, we introduce specific description of the CN reconfiguration under the terms of theory of structures dynamics control based on multiple-structural macrostates. It allows comprehensive simultaneous consideration of various structures and functions for the CN execution. We start this paper with the state-of-the-art research analysis to the problem of the CN reconfiguration. Section 3 presents conceptual model algorithms of CN reconfiguration based on the theory of structure dynamics control. We conclude this paper with mathematical models and algorithms of CN parametrical and structural adaptation, which implement the described conceptual models of the CN reconfiguration. These models and algorithms make it possible to embed the reconfiguration in the CN control loop and to interlink planning and execution phases to increase the whole CN efficiency. Reconfiguration embedding in the CN control loop akes it possible to reveal both CN structural-technological reserves and new CN potentialities.
To improve convergent speed of the neural network for machining process control, Generalised Entropy Square Error (GESE) function is defined and its availability is proved theoretically. Combining information entropy and wavelet analysis with neural network, a neural network adaptive control system is presented. Replacing the mean square error criterion of back propagation algorithm with the GESE criterion, an adaptive control algorithm is proposed. The proposed system is then applied to the online control of the cutting force by searching adaptively wavelet base function and self-adjusting scale parameter, translation parameter of the wavelet and weights of the network. The designed system is of fast response and less overshoot, and the suggested algorithm can tune adaptively the feed rate online till achieving a constant cutting force approaching the reference force in varied cutting conditions, thus raising machining efficiency and protecting tool. Finally, simulation and experiment examples are also given to demonstrate the effectiveness of the proposed system and algorithm.
The EPCglobal has recently ratified the EPC-IS standard, which insulates enterprise applications from understanding the details of how individual steps in a business process are carried out. However, few processes are described on the basis of this framework. In this paper, we present an overview of EPC-IS and accordingly leverage its event semantics to formulate the business context for prominent warehouse management (WM) processes. Specifically, we provide a fairly general description of WM business processes in terms of EPC-IS events. These events have been validated and used in the scope of realistic RFID deployments in different enterprises. Based on this experience we believe that these baseline descriptions could serve as templates for a wide range of RFID WM deployments. We also provide insights on how these descriptions could be used in the scope of a wider business process management framework, which could be amenable by graphical tools.
Across the globe, more companies are pursuing economically viable green manufacturing in order to efficiently reduce or eliminate pollutants and hazardous substances. Companies are seeing the economic impact of green manufacturing because it creates sustainable development, allows opportunity for re-investment, supports cost saving strategies, and has a positive impact on the bottom line. These benefits support many strategic initiatives and provide a competitive advantage. In order to implement green processes and products, companies exploit product lifecycle management (PLM) practices to achieve their strategic initiatives. PLM is a process that focuses on managing a product through its entire lifecycle, from the conception to the disposal or recycle of the product. PLM helps a business reduce the use of time, materials, and energy by using a shared information core. International laws and standards have a direct effect on the product lifecycle. Through the PLM information core, companies can integrate environmentally friendly practices into their business. The focus of this paper is to investigate why companies practice green manufacturing and how PLM supports environmentally friendly initiatives. The investigated companies are taken from the Global Round Table on Climate Change. In particular, this paper examines how PLM drives green manufacturing to improve environmental performance while meeting financial and long-term sustainability. Mechanisms to increase energy efficiency, de-carbonization, reduction of harmful emissions, and better land management practices such as reducing landfill waste will be studied. This paper also includes a review of interviews and examples from previous studies.
In this paper, we quantify an important management problem, which is how a company should respond to cyclical shocks of different amplitudes and duration when time delays are present in the factor input adjustment process. Our objective is to show how different shock profiles affect the amplitude and wavelength of the production path. We also consider the extent to which cyclical shocks generate long-run persistence in the time-path of output. Finally, our analysis suggests a scheme, which is not based simply on calendar time, for classifying different shock profiles as short or long.
This study explores how business process reengineering methodology is adopted to innovate the product development process for global manufacture, through the case of a small manufacturing enterprise. Diffusion of innovation theories are used to explain the influence of variables at individual, organisational and environmental levels of analysis. The in-depth case study shows the difficulties innovating processes face in catching up with rapid change management within the changing situation of a dynamic company both in the justification of a BPR project and gaining support through the project. The conclusion is that variables at all three levels are important in explaining the adoption of business process reengineering methodology with the environmental level being considered most powerful in its impact. Given these findings, the authors qualify the predictive power of rational models that focus on the individual level of analysis and urge more balanced methodologies that examine the joint impact of the three levels of analysis for process innovation development in SMEs.
This project explores the barriers that hamper SMEs from adopting new process technologies. Previous research suggests that process innovations enhance productivity appreciably. Often, economics literature on new technology adoption relates to developing countries; do these findings and theories hold for industrial countries' SMEs? The paper reports a national survey sent to SMEs within the engineering and electronic industries. The regression equation indicates that process innovation was a response to competition, as firms were ''pushed'' to introduce new techniques. Yet, our research highlights other factors: the importance of strategic plans and a focus on innovation in those firms with the capacity to raise their heads above the day-to-day struggle for survival.
Nowadays, the role of Information and Communications Technologies (ICTs) to facilitate the improvement of efficiency along the supply chain must be outlined. Thus, the aim of this paper is twofold: firstly, to know the potential contribution of ICTs implementation (related to packaging and to logistics use) to the improvement of competitiveness in companies and secondly, to know the level of adoption in the Spanish food sector (sample of 300 companies) of these ICTs (barcodes, Electronic Data Interchange (EDI) and Radiofrequency Identification (RFID)), including the main causes that hinder a higher diffusion in companies.
The manufacturing sector in general, and small manufacturers in particular, are faced with fierce national, regional and global competition. Trade alliances, such as NAFTA, which have been entered into by the USA will add to this competitive burden. Modernisation of manufacturing facilities through the infusion of computerised manufacturing and information processing technology has become imperative in this environment. A body of research is only now beginning to be developed for the identification of the issues and considerations that impede or facilitate modernisation of small manufacturing. This research is an attempt to contribute towards filling the gap in understanding of small manufacturing issues and concerns.