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With new market developments and e-commerce, there is an increased use of and interest in automation for order picking. This paper presents a systematic review and content analysis of the literature. It has the purpose of understanding the relevant performance aspects for automated, or partly automated, OPSs and identifying the studied links between design and performance, i.e. identifying which combinations of design aspects and performance aspects have been studied in previous research. For this purpose, 74 papers were selected and reviewed. From the review, it is clear that there has been an increased number of papers dealing with the performance of automated, or partly automated, OPSs in recent years. Moreover, there are differences between the different OPS types, but, overall, the performance categories of throughput, lead time, and operational efficiency have received the most attention in the literature. The paper identifies links between design and performance that have been studied, as well as links that appear to be under-researched. For academics, this paper synthesises the current knowledge on the performance of automation in OPSs and identifies opportunities for future research. For practitioners, the paper provides knowledge that can support the decision-making process of automation in OPSs. [ABSTRACT FROM AUTHOR]

Despite its potentialities, Lean Automation (LA) has not attracted attention for over two decades. However, due to the new opportunities offered by Industry 4.0 technologies, LA revives expectations and enthusiasm. This paper aims to test empirically the association of LA, in the form of integration of Lean practices and Industry 4.0 technologies, and operational performance. The paper used a rigorous, multi-stage empirical method and data from a set of more than 200 manufacturing firms; one representative from each of the studied companies filled in a survey on Lean practices and Industry 4.0 technology bundles, with productivity, delivery, inventory, quality as performance indicators. The extensive survey results helped in identifying underlying components of LA: one focuses on operational stability and includes practices and technologies supporting efficiency along the supply chain; the other focuses on streamlining the flow, on fastening the process to reach the customer. Moreover, it demonstrates the positive correlation between LA and operational performance. Besides its contribution to the body of knowledge on LA, this research paves the base of improving academics and practitioners understanding of the integration of new technologies with Lean Production systems. [ABSTRACT FROM AUTHOR]

As an information technology that could significantly improve supply chain visibility and process automation, blockchain has been extensively applied in the field of supply chain finance (SCF). However, tradeoffs among the security, the operation cost, and the efficiency of the blockchain system may cause the SCF system dominated by a financial institution to inevitably fall into the dilemmas of risky or un-economic if the blockchain technology is applied inappropriately. Therefore, the objective of this paper is to optimise the blockchain application in the financial institution-based SCF system. We first analyse the application of blockchain security in SCF, and then the performance tradeoffs of blockchain and its impact on the performance of the supported SCF system. Based on the analysis above, an optimisation approach has been proposed and a corresponding non-linear integer programming (NIP) model has been constructed to select the best blockchain design schemes for the SCF system to achieve overall optimal in terms of security, cost, and efficiency. A designed ant colony algorithm is used to solve the optimisation problem. An application case analysis is used to verify the feasibility and effectiveness of the optimisation model. [ABSTRACT FROM AUTHOR]

A flexible manufacturing system (FMS) due to its ability of being flexible in nature is concerned with automatic production of different parts in medium range. In short, it can be regarded as an automated manufacturing system. In this paper, an insight on previous work in the area of FMS modelling has been provided with an overview of research and development for better understanding of FMS. It serves as a medium for investigation of work that are accomplished by using different modelling techniques in FMS like mathematical, artificial intelligence, hierarchical, multi criteria decision-making method, Petri Nets and simulation. This paper will help researchers who are keen to do research in the area of FMS modelling, by highlighting contribution of available techniques in the field of FMS. It will also help them in deciding which modelling techniques can be used for a given problem. At last, comparison of different parameters considered in the recent papers of modelling FMS has been provided in the form of Table, along with a clear vision related to those works that still need to be investigated. [ABSTRACT FROM AUTHOR]

Future manufacturing systems need to be more flexible, to embrace tougher and constantly changing market demands. They need to make better use of plant data, ideally utilising all data from the entire plant. Low-level data should be refined to real-time information for decision-making, to facilitate competitiveness through informed and timely decisions. The Line Information System Architecture (LISA), is presented in this paper. It is an event-driven architecture featuring loose coupling, a prototype-oriented information model and formalised transformation services. LISA is designed to enable flexible factory integration and data utilisation. The focus of LISA is on integration of devices and services on all levels, simplifying hardware changes and integration of new smart services as well as supporting continuous improvements on information visualisation and control. The architecture has been evaluated on both real industrial data and industrial demonstrators and it is also being installed at a large automotive company. This article is an extended and revised version of the paper presented at the 2015 IFAC Symposium on Information Control in Manufacturing (INCOM 2015). The paper has been restructured in regards to the order and title of the chapters, and additional information about the integration between devices and services aspects have been added. The introduction and the general structure of the paper now better highlight the contributions of the paper and the uniqueness of the framework. [ABSTRACT FROM AUTHOR]

This paper describes a novel method for automated generation of process plans and numerical control (NC) part programs from 2D drawing image files. Four algorithms are introduced in this paper. First algorithm deals with extraction of geometrical data, second algorithm used to recognise turned features from the extracted geometrical data base. Recognised features are then passed to third and fourth algorithms for generation of process plans and NC part programs respectively. Using proposed system, it is possible to achieve fully automation of recognition of turned features, generation of process plans and NC part programs. Thus, it becomes possible to go from scanned image to finished product in a fully automated fashion. These algorithms have been implemented on mini-computer to process image data, and display recognised turned features, process plans and creates output files containing NC part programs. These NC part programs are verified through CNC train simulation package. The results are satisfactory. [ABSTRACT FROM PUBLISHER]

There are some issues which have to be addressed when designing an automated guided vehicles system (AGVS) such as flow-path layout, traffic management, the number and the location of pick-up and delivery points, vehicle routing and so on. One of the AGVS guide path configurations discussed in the previous researches includes a single-loop which is the subject of this paper. Many researchers have worked on the subject of finding the shortest single loop in a given block layout. This problem has been already proved to be NP-complete. Finding the location of pick-up/drop-off (P/D) stations on a given loop is what is typically done, but locating the loop and the P/D stations simultaneously is actually more realistic. In this paper, a genetic algorithm (GA) has been developed to determine these two simultaneously. The algorithm only reproduces the feasible solutions. The objective is to minimize the total traveled distance. A from-to chart and a block layout are the inputs and a unidirectional loop including its corresponding direction and along with the locations of the P/D stations on the loop are the outputs. To show the efficiency of the algorithm, the associated results for some sample problems have been compared with the results generated by LINGO for the equivalent mixed integer programming (MIP) problem. Computational results show the efficiency of the algorithm in solving relatively large size problem. [ABSTRACT FROM AUTHOR]

In this paper, we look into the loading problem of a flexible manufacturing system (FMS) that is made up of several identical flexible manufacturing machines (CMMs). These machines are capable of different operations as long as the required tools are provided to them. The loading problem studied in this paper is a pre-release problem that deals with the pre-assignment of parts and tools before the process of an FMS begins. There are two objectives that one would like to achieve. They include minimising the number of tool-shortage occurrences and balancing the workload between machines. Since one cannot directly minimise the number of tool-shortage occurrences at the current pre-release stage, a surrogate objective of minimising the total tool-capacity shortage (TTCS) is adopted. Furthermore, because of the 'tool movement policy' assumption, our loading problem only involves assigning parts and tools to each machine. In this paper, we propose a part-and-tool assignment method that combines fuzzy c-means, SA (simulated annealing), and an optimal tool-assignment algorithm. The proposed part-and-tool assignment method is designed to be interactive. Because of this interactive nature, human designers can experiment with different evaluation criteria or reset the parameters of SA to look for alternative solutions. An example is given which illustrates the proposed part-and-tool assignment method. From the example, one can see that the proposed method is very efficient and effective in finding good-quality solutions. [ABSTRACT FROM AUTHOR]

This paper addresses the deadlock-free scheduling problem in Flexible Manufacturing Systems. An efficient deadlock-free scheduling algorithm was developed, using timed Petri nets, for a class of FMSs called Systems of Sequential Systems with Shared Resources (S4R). The algorithm generates a partial reachability graph to find the optimal or near-optimal deadlock-free schedule in terms of the firing sequence of the transitions of the Petri net model. The objective is to minimize the mean flow time (MFT). An efficient truncation technique, based on the siphon concept, has been developed and used to generate the minimum necessary portion of the reachability graph to be searched. It has been shown experimentally that the developed siphon truncation technique enhances the ability to develop deadlock-free schedules of systems with a high number of deadlocks, which cannot be achieved using standard Petri net scheduling approaches. It may be necessary, in some cases, to relax the optimality condition for large FMSs in order to make the search effort reasonable. Hence, a User Control Factor (UCF) was defined and used in the scheduling algorithm. The objective of using the UCF is to achieve an acceptable trade-off between the solution quality and the search effort. Its effect on the MFT and the CPU time has been investigated. Randomly generated examples are used for illustration and comparison. Although the effect of UCF did not affect the mean flow time, it was shown that increasing it reduces the search effort (CPU time) significantly. [ABSTRACT FROM AUTHOR]

Scheduling of production in flexible manufacturing systems (FMSs) has been extensively researched over the past years and it continues to attract the interests of both academic researchers and practitioners. The generation of new and modified production schedules is becoming a necessity in today's complex manufacturing environment. Genetic algorithms are used in this paper to obtain an initial schedule. Uncertainties in the production environment and modelling limitations inevitably result in deviations from the generated schedules. This makes rescheduling or reactive scheduling essential. Four different types of uncertainties that normally cause discrepancies between the actual output and the planned output are considered in this paper. These include unforeseen machine breakdowns, increased order priority, rush orders arrival and order cancellations. In this paper, the current status of the shop is considered while rescheduling. The proposed algorithms revise only those operations that must be rescheduled and can, therefore, be used in conjunction with the existing scheduling methods to improve the efficiency of flexible manufacturing systems. [ABSTRACT FROM AUTHOR]

Composite material usage in aircraft has been rising since the 1990s, with significant increases in manufacturing productivity and repeatability due to automation in the production of aeronautic parts made of composite materials, becoming a strong driver for widespread adoption of composites in this industry. Automated Tape Layup (ATL) and Automated Fibre Placement (AFP) are two of the most important automated manufacturing technologies within aeronautics composites, although their cost implications and economic comparison have not been widely studied. This paper presents an economic evaluation of ATL and AFP technologies. Using process-based cost models, the manufacturing process of a horizontal stabiliser is modelled, determining for each technology the associated consumption and use of resources and their implications towards the part final cost. Results show that ATL is less expensive than AFP, due to lower material costs, although with less material efficiency and slower cycle time. [ABSTRACT FROM AUTHOR]

Cost analysis is crucial in the design of assembly systems and the decision on their level of automation (LoA). This paper presents a cost estimation model of assembly system that is used to decide their LoA during the early phase of projects. Based on an extensive literature review, a complete cost model integrating multiple cost drivers is proposed. This model is then exploited to create the objective function of an integer linear programme model utilised to solve the LoA decision problem. The work provides a way to perform cost estimation of assembly systems alternatives and to decide the most appropriate LoA in assembly. The cost estimation model is built with a parametric approach allowing the definition of various optimisation objectives. The proposed integer programme, complement this approach by proposing the suitable constraints set, that describes the LoA decision problem. [ABSTRACT FROM AUTHOR]

Factory (re) design involves the appropriate utilisation of product, process and resource knowledge in the determination of suitable configurations of physical factory facilities which have the potential to meet industrial and organisational requirements. Different independent semantic modelling standards exist for products, processes and resources but to automate and facilitate the selection of factory resources, there is the need to semantically integrate resource capabilities with product and process requirements. This paper defines a ‘recipe-based’ approach to design factories and it is based on the assumption that capabilities and competences of reusable components (or building blocks) of factory resources can be semantically modelled and matched with product–process requirements. This approach will enable Factory Designers and Engineers to decide on relevant resource systems within finite, valuable and defined sets of requirements. [ABSTRACT FROM PUBLISHER]

In this paper, a two-stage ant colony optimisation (ACO) algorithm is implemented in a multi-agent system (MAS) to accomplish integrated process planning and scheduling (IPPS) in the job shop type flexible manufacturing environments. Traditionally, process planning and scheduling functions are performed sequentially and the actual status of the production facilities is not considered in either process planning or scheduling. IPPS is to combine both the process planning and scheduling problems in the consideration, that is, the actual process plan and the schedule are determined dynamically in accordance with the order details and the status of the manufacturing system. The ACO algorithm can be applied to solve IPPS problems. An innovative two-stage ACO algorithm is introduced in this paper. In the first stage of the algorithm, instead of depositing pheromones on graph edges as in common ant algorithms, ants are directed to deposit pheromones at the nodes to select a set of more favourable processes. In the second stage, the set of nodes not selected in the first stage will be ignored, and pheromones will be deposited along the graph edges while the ants traverse the paths connecting the selected set of nodes. [ABSTRACT FROM PUBLISHER]

Automated storage and retrieval systems (AS/RSs) and autonomous vehicle storage and retrieval systems (AVS/RSs) are two competing technologies for the handling, storage and retrieval of unit-loads in the reserve section of an automated warehouse. In this paper, we model variants of the two systems as an open queuing network (OQN) and use an existing tool for the analysis of OQNs, called the manufacturing system performance analyser (MPA), for analysing the performance of the AS/RS and AVS/RS. Experimental results are provided to show that MPA is a better choice than simulation to quickly evaluate alternate configurations of the two systems. We use MPA to answer a series of design questions for AS/RS and AVS/RS design conceptualisation. [ABSTRACT FROM AUTHOR]

This paper provides a novel method for determining the constraining effect of resources in a manufacturing system using discrete event simulation. Traditionally manufacturing systems are constrained by one or more bottlenecks. Eliminating or mitigating the bottleneck will speed up the system throughput. However, bottlenecking resources generally only refer to machines, and primarily focus on flow-shops not job-shops. One important resource we believe that is often overlooked is workers and their associated skills, and we propose that a particular skill could be flagged as a bottleneck resource. We define new metrics known as resource constraint metrics (RCM) for measuring the constraining effect of a resource on the entire manufacturing system. These metrics are flexible and differentiate between the constraining effects of machines and their requested skills. The metrics can also deal with complex workflows with alternative routing, alternative resources, calendars (a necessary consideration when dealing with workers), worker performance, and multiple modes of operation of machines (e.g. run, setup, and maintenance). The use of RCMs in simulation aids in real-world decision-making, by determining which resource should be focussed on and improved to reduce the overall system feeling constrained. This will have the effect of increasing throughput or at least providing the capacity for increased throughput. [ABSTRACT FROM AUTHOR]

This paper deals with assigning operators to various operations in a labour-intensive cellular environment. The operator skill levels and skill-based operation times are used as opposed to the classical approach of using standard times. A three-phase approach is developed to tackle the entire problem: (1) finding alternative cell configurations; (2) loading cells and finding crew sizes; (3) assigning operators to operations. A multi-period analysis is performed to study the main issues in this paper. Mathematical models are used in all phases. Two heuristic approaches (Max, MaxMin) are developed for operator assignment in phase III. Both heuristics are compared and their impact on operator learning and forgetting is also investigated. Results show that the proposed approaches in operator assignment outperform the classical approach of using standard times. Heuristic Max resulted in lower makespan and higher idle times whereas heuristic MaxMin improved operator skills more uniformly. [ABSTRACT FROM AUTHOR]

In order to satisfy the current market demands for shorter lead-time and high quality products manufacturing enterprises have to integrate their design, production and quality assurance functions. In a computerized environment these functions are manifested in CAD, CAM and AVI respectively. In the recent past, much success has been achieved in integrating CAD and CAM. It is widely accepted that feature recognition systems, both 2D and 3D, have been one of the main contributors to CADCAM integration. However the existing feature recognition systems could not link CADCAM and AVI and hence could not close the manufacturing loop that ensures the production of designer intended features. This is mainly because the input formats of existing feature recognition systems and AVI systems have been different in format and structure. The system described in this paper attempts to redress this deficit at least partially by using a monochrome bitmap as a generic input, to which both CAD models and vision images could be converted. Hence the input to the system takes a form of third angle orthographic views, however, without hidden lines in order to facilitate dealing with vision images. This, in turn, augments difficulty faced in recognizing features. To overcome this difficulty, the help of evolutionary computing and artificial intelligence is sought in this system. This paper outlines the basis of a 2D feature recognition system that uses artificial neural networks along with a chain code method for eliciting feature information from monochrome bitmap of either vision images or CAD inputs hence providing a generic framework to integrate CADCAM and AVI. With further improvement to deal with geometry of the features, annotations and symbols this system could also help to salvage the massive store of engineering knowledge that exists in 2D form. [ABSTRACT FROM AUTHOR]

This paper discusses the planning module of system that has been developed in a research project investigating the possibilities for automatic planning of press brakes. Only limited attention has been given to production-planning problems for bending processes in the sheet-metal industry. A well-considered production-planning module provides an important opportunity for cost saving and flow-time reduction. The module will support and may replace an experienced planner. Under certain assumptions, the planning problem can be modelled both ways as a Travelling Purchaser Problem (TPP) and as a Generalized Travelling Salesperson Problem (GTSP). A hierarchical decomposition approach is presented to solve the TPP, while the GTSP is solved using guided local search (GLS). These methods are compared based on a set of problems from a real production environment and perform well. [ABSTRACT FROM AUTHOR]

This paper presents a novel approach to integrate VR and CAD for virtual assembly, namely, CAD linked virtual assembly environment. Compared with most existing VR and CAD integration approaches, the proposed approach is a kind of external integration with a CAD system through automation interfaces. A novel hybrid virtual assembly model is developed in this paper to support this external integration. It works as a combinator that links the precisely represented design dataset in CAD models and the corresponding hierarchically structured virtual assembly dataset in the VR application. With this model, a framework has been developed to embed and apply CAD assembly constraints on the virtual assembly structure. Constraint-based manipulation is then implemented in the virtual assembly environment. Moreover, with this framework, advanced computations, such as runtime DOF determination, disassembly directionality computation, and assembly/disassembly sequence generation, which rely on assembly constraint information, can be feasibly integrated into the virtual assembly application with much less effort. The approach is also more practical in terms of implementation due to two advantages: (1) It does not require the implementation of a complicated support for solid modelling in the virtual assembly application. (2) A virtual assembly environment can be automatically created and updated from the linked CAD models. [ABSTRACT FROM AUTHOR]

On-line vehicle dispatching rules are widely used in many facilities such as warehouses and manufacturing facilities to control vehicles' movements. Single-attribute dispatching rules, which dispatch vehicles based on only one parameter, are usually used. However, multi-attribute dispatching rules prove to be better in general. In this paper, we study the impact of reassigning moving vehicles on some good dispatching rules, both single- and multi-attribute, in the literature. Results suggest that reassigning moving-to-park vehicles has a significant positive effect on reducing the average load waiting time. We evaluate the dispatching rules' performance using the experimental design of a real-life case study. The performance criteria are: minimizing the average load waiting time, keeping the maximum load waiting time as short as possible and utilizing better vehicles. The results show that the combined dispatching rules which integrates multi-attribute dispatching and vehicle reassignment yields the best performance overall. [ABSTRACT FROM AUTHOR]

Assembly errors can occur in a robotic assembly system. In this paper, a method that predicts an assembly error is proposed. It considers that assembly errors occur under the condition that the geometric trajectory of a mated part and the relational position and orientation of a base part are outside the allowable tolerance. A certain point, which is determined by using a physical light reflectance model of a mated part, is followed with two high-speed cameras. A statistical pattern recognition method in which explanatory variables are tracked points in a three-dimensional space is then employed to predict an assembly error. The proposed method is applied to a peg-in-a-hole assembly by a selective compliance assembly robot arm (SCARA)-type robot and its potential value is discussed. [ABSTRACT FROM AUTHOR]

The concept of a virtual cellular manufacturing system (VCMS), which operates very much like a traditional cellular manufacturing system (CMS), has attracted considerable attention in recent years. Unlike traditional cellular manufacturing systems, virtual cellular manufacturing systems are most suitable in production environments that experience frequent product mix changes. Whereas, in traditional CMS, the shop floor configuration is fixed, in VCMS the shop floor configuration changes in response to changes in product mix over time. Therefore, the life of a given shop floor configuration continues as long as the product mix remains relatively unchanged. Furthermore, whereas in traditional cellular manufacturing systems, a machine cell occupies a contiguous region of the shop floor, the same is not necessarily true with virtual cells. Virtual manufacturing cells are simply logical cells in which the machines belonging to the same cell need not occupy the same contiguous area. Because cell members are logical instead of physical, machines in a cell can be at any location on the floor. In this paper, we present a methodology for designing virtual manufacturing cells. [ABSTRACT FROM AUTHOR]

Over the past decade, the development of supervisory controllers for automated manufacturing systems has been an active area of research with particular attention focusing on deadlock avoidance. Most work to date assumes that system workstations do not fail. This paper considers deadlock and blocking problems in systems with one unreliable workstation, the objective being to develop supervisory control policies that allocate workstation buffer space so that failure of the workstation server does not propagate through blocking to effectively stall other portions of the system. In short, when a workstation fails, the system should automatically continue producing all part types not requiring that workstation. To accomplish this, the supervisory controller must simultaneously avoid deadlock and buffer allocation states that are not feasible initial states for the 'reduced' system resulting from workstation failure. When the workstation fails, the controller must then simultaneously avoid both deadlock and buffer allocation states that are not feasible initial states for the original system so that transition to normal operation is smooth when the failed workstation is restored. This paper shows this class of problems through several examples, identifies properties that controllers must satisfy to deal effectively with these problems and develops a polynomial control policy that satisfies these properties. [ABSTRACT FROM AUTHOR]

Manufacturing systems have evolved to adopt a mixed-model assembly line enabling the production of high product variety. Although the mixed-model assembly system with semi-automation (i.e. human involvement) can offer a wide range of advantages, the system becomes very complex as variety increases. Further, while the complexity from different options can worsen the system performance, there is a lack of quantifiable models for manufacturing complexity in the literature. Thus, in this paper, we propose a novel method to quantify manufacturing choice complexity for the effective management of semi-automated systems in a mixed-model assembly line. Based on the concept of information entropy, our model considers both the options mix and the similarities between options. The proposed model, along with an illustrative case study, not only serves as a tool to quantitatively assess the impact of choice complexity on total system performance, but also provides an insight into how complexity can be mitigated without affecting the overall manufacturing throughput. [ABSTRACT FROM PUBLISHER]

Human factors such as employee morale and workers skills greatly influence the successful adoption of automated and advanced manufacturing technologies. For newly industrialised countries, the evaluation of these factors before technology selection is particularly paramount. Countries such as Brazil are in the critical early stages of technology adoption and low rates of secondary education and scarcity of technicians reinforce the importance of assessing human factors before the actual technology implementation. Although methods have been proposed to evaluate intangible aspects, the lack of a structured approach to identify and quantify human factors still constitutes a major hurdle. The paper describes a framework and process to assist managers in identifying and evaluating human factors in the selection. The approach was tested in eight companies in Brazil. The results indicated that the main advantages of the proposed approach are: (a) provide a comprehensive justification of technology adoption by identifying and quantifying intangible aspects; and (b) supply a practical process to be incorporated into the selection decision-making process. [ABSTRACT FROM AUTHOR]

Satisfying the end-of-life vehicle (ELV) legislations is essential for business activities in some markets. However, with the lack of similar regulations for the treatment of ELV, automotive manufacturers follow different green practices. These practices can be a complex task such as an eco-design strategy or issuing a guideline or manual for the end-of-life phase of the product. Each of these practices also has different impacts on the other players in the market. Several factors contribute to manufacturers’ gain as a result of applying green practices. The uncertainties in these features and the absence of data availability raise the difficulty in the manufacturers’ profit estimation. This paper proposes a new approach to analysing automotive manufacturers’ strategic choice in applying ELV practices considering the competitive advantages of performing these practices and the interaction between players. A joint application of evolutionary game theory and fuzzy rule-based approach is proposed to analyse the strategic behaviour of automotive manufacturers. The proposed model provides a simulation environment for testing the interaction of the different market factors and players’ action. The experimental design highlights the validity of the model and its implications. The result reveals that when we have two populations of players including the market leader in recycling initiatives and market reader; the market elements such as ‘elasticity of demand to price’ and ‘loyalty of consumers to market leader’ play an essential role in determining the stable strategy of the game. [ABSTRACT FROM PUBLISHER]

This paper provides a survey of the main advanced control techniques currently adopted in factory automation. In particular, it focuses on five classes of control approaches, namely: model-based control, control based on computational intelligence, adaptive control, discrete event systems-based control and finally event-triggered and self-triggered control. A particular focus is put on the most significant and recent contributions in these areas with attention to their application in the factory automation domain. Finally, open issues, challenges and the requirements of further research efforts for each class are pointed out. [ABSTRACT FROM AUTHOR]

In this paper, the issue of inspection planning for a coordinate measuring machine (CMM) is addressed. A method is presented for the automation of the probe selection decision, with the ultimate goal of determining the set of workpiece orientations recommended for use on a CMM equipped with an indexable probe. The methodology uses a computer-aided design (CAD) model of the workpiece and a list of tolerance information as input to a feature accessibility algorithm. For each inspection feature, the algorithm generates a feasible set of probe orientations using information about potential probe/workpiece collisions, and computes an estimate of its percentage accessibility. [ABSTRACT FROM AUTHOR]

Firms that adopt cellular manufacturing (CM) often need to restructure their products, personnel, equipment, factory management and organisation culture. Despite voluminous literature on CM, only a few case studies related to cellularisation exist. Therefore, to enhance understanding in this area, this paper presents a longitudinal case study on cellularisation in an electronic assembly plant. Six years of data were collected from the observations and discussions of an industrialist and an academician. Events instrumental to the persistence of CM were highlighted, with reference to path dependence analysis. Cellularisation is not entirely evolutionary or teleological but is an interplay of the two; it is significantly influenced by the positive feedback of self-reinforcing mechanisms after departing from critical junctures. The observed self-reinforcing mechanisms were expounded and divided into six categories. [ABSTRACT FROM AUTHOR]

In competitive and uncertain business environments, manufacturing firms face various challenges requiring quick response, customisation and cost effectiveness to sustain competitive advantage. This paper proposes a segment set-based approach for the part input sequencing problem of flexible manufacturing systems (FMSs). The segment set theorems are built for the development of the segment set-based approach for the problem. A numerical study is done using simulation, and validated through statistical analyses. Our approach results in the significant performance improvement of the FMSs. Managerial implications are discussed. Further research is also provided. [ABSTRACT FROM AUTHOR]

The paper describes a semi-heterarchical control solution for mixed planning and scheduling, routing and job execution in flexible manufacturing systems based on the paradigms of holonic manufacturing and product-driven automation. The main feature of the control solution is the bidirectional switching of the operating mode (scheduling, routing) between centralised and decentralised in the presence of perturbations to ensure as long as possible both global optimisation and agility to changes in batch orders, while featuring robustness to disturbances in the production environment. At the theoretical level, the control solution is described in terms of generic structural and dynamic models. The implementation is done using a multi-agent Java Agent Development Framework framework. [ABSTRACT FROM AUTHOR]

In order to make more competitive electronic products, major electronics companies struggle to design products with a thin shape and complex convergence functionalities without any lead-time and cost increase. Also, the development mission of a project is changed continuously to catch up with the competitor’s products in a short time and the importance of aesthetic design is getting bigger and bigger in these days. In many cases, shape changes bring the electrical layout changes of a notebook computer main board and vise versa. Those development environmental changes make the engineers harder and harder and require more collaboration between electrical and mechanical engineers to reduce development time and design errors occur from early design stage. In this paper, a collaborative design environment consists of a web-based project management system and automated printed circuit board (PCB) generation and validation system is proposed. The web system is used for project management and design data exchange including electrical CAD (ECAD) data and related technical documents between ECAD and mechanical CAD (MCAD) engineers. By using this project management web portal, engineers can share the design information with design change history. ECAD data in Intermediate Data Format can be automatically validated in 2D domain while sending the ECAD data via web system. To generate a full 3D quality product model with PBA in MCAD side, an automated 3D PCB generation and assembly clearance checking module is developed. [ABSTRACT FROM PUBLISHER]

Continuous advances of sensor technology and real-time computational capability are leading to data-rich environments to improve industrial automation and machine intelligence. When multiple signals are acquired from different sources (i.e. multi-channel signal data), two main issues must be faced: (i) the reduction of data dimensionality to make the overall signal analysis system efficient and actually applicable in industrial environments, and (ii) the fusion of all the sensor outputs to achieve a better comprehension of the process. In this frame, multi-way principal component analysis (PCA) represents a multivariate technique to perform both the tasks. The paper investigates two main multi-way extensions of the traditional PCA to deal with multi-channel signals, one based on unfolding the original data-set, and one based on multi-linear analysis of data in their tensorial form. The approaches proposed for data modelling are combined with appropriate control charting to achieve multi-channel profile data monitoring. The developed methodologies are demonstrated with both simulated and real data. The real data come from an industrial sensor fusion application in waterjet cutting, where different signals are monitored to detect faults affecting the most critical machine components. [ABSTRACT FROM PUBLISHER]

Developing effective supervisory control policies that guarantee deadlock-free operations for automated manufacturing systems (AMSs) has been an active area of research for the past two decades or so. A great deal of work has been done for the systems with reliable resources; while only a few works are about unreliable resources. This paper addresses the robust deadlock supervisory control problem in AMSs with multiple unreliable resources. The objective is to develop a robust supervisory control policy for AMS under which the system can continue producing all part types not requiring any of the failed resources without manual intervention. Our policy is made up of a modified Banker’s Algorithm and a set of remaining resource capacity constraints. A state is feasible if and only if it satisfies both of them. By using the improved version of the existing Banker’s Algorithm, our control policy has more permissibility. An example is provided to illustrate that the policy gains advantage over the original one in permissiveness. [ABSTRACT FROM PUBLISHER]

In today’s competitive environment with increasingly faster deliveries and smaller order sizes, material handling providers are progressively developing new solutions. A more recent development in automated material-handling technology for unit load storage and retrieval is the autonomous vehicle storage and retrieval system (AVS/RS). The paper investigates the main design trade-offs for this new solution using simulation, and proposes a comprehensive design framework. Using data from a recently implemented AVS/RS, the application of the proposed framework is presented and the key design differences between the two types of AVS/RS configuration (i.e. tier-captive versus tier-to-tier) are identified. [ABSTRACT FROM PUBLISHER]

In today's competitive scenario of increasingly faster deliveries and smaller order sizes, material-handling providers are progressively developing new solutions. A recent, automated material-handling technology for unit load storage and retrieval consists of an autonomous vehicle storage and retrieval system (AVS/RS). The present paper presents an analytical model to estimate the performances (the transaction cycle time and waiting times) of AVS/RS for product tote movement. The model is based on an open queuing network approach. The model effectiveness in performance estimation is validated through simulation. [ABSTRACT FROM PUBLISHER]

This paper presents a computational environment as a tool for supporting the implementation of control coding of an automated manufacturing system. The proposed environment considers a cyclic three-stage control development – modelling, synthesis and implementation – until the real system accomplishes the required specification, resulting in the automated and integrated manufacturing system. The research details the three stages and describes the steps executed for each one. The mathematical formalism used in this work is also presented, as a basis for control implementation. The implementation environment is proposed in order to validate the control structure of this formalism and to allow a progressive integration of control hardware and software. To submit to a test and validate the proposal environment, two experiments are performed, in two different manufacturing systems. Thus, it is demanded that the control system can be reconfigurable in a fast and reliable way. [ABSTRACT FROM PUBLISHER]

Die-casting is one of the methods used to produce a large number of components with a good surface finish by injecting cast alloys into a metal mould under high pressure. The design of a die-casting die requires human expertise and is normally performed by trial and error, which leads to monetary and time losses. Automation at the initial die design stage would result in higher productivity and would reduce the production lead time. Decisions regarding the number of cavities, the layout pattern and the placement of cavities in die-casting are critical for die design and manufacturing. This paper presents research work on a system for computer-aided cavity layout design for die-casting dies. The proposed system consists of three modules: (1) determination of number of cavities; (2) selection of layout pattern; and (3) placement of cavities in the die base. It enables die designers to generate a cavity layout design automatically from a computer-aided design (CAD) file of the part with little information provided manually. The optimal number of cavities is determined by considering economic, technical, geometrical and time limitations, followed by the selection of a layout pattern. Thereafter, cavities are placed in the die base. The developed system depends on a database of die-casting machines and materials along with a knowledge base of die design. This system has been tested on a number of die-casting parts and results have been found to be along the lines of those obtained by the industry. The proposed system is more comprehensive than those presently available and is a step in the right direction for design-manufacturing integration for die-casting. [ABSTRACT FROM AUTHOR]

The field of factory automation has been the target of many recent research efforts related to improving overall efficiency and reconfigurability in order to effectively enable the advent of mass customisation. These efforts have promoted the adoption of autonomous, loosely-coupled devices aimed at simplifying the integration of modular production cells, as well as new production control methodologies which aim to bring efficiency, agility and quick turnaround to the production process. As these new production paradigms start to trickle down to the factory floor, a new set of tools must be developed in order to support their implementation. Recent advances in computing power and functionality from the past decades have opened up the opportunity to not only improve the processing capabilities within control devices but to implement engineering tools which will support the systems engineers in building the modular production floor. This paper presents the development of such a tool which facilitates the implementation of said devices, and their functionalities which aim to simplify the configuration and layout of modular, service-oriented devices in a virtual production line. The tool can then be used as a simulation platform in order to test out different layouts and production processes. [ABSTRACT FROM AUTHOR]

Flexible manufacturing system (FMS) is described as a set of computerised numerical controlled machines, input–output buffers interconnected by automated material handling devices. This paper develops a bi-objective operation allocation and material handling equipment selection problem in FMS with the aim of minimising the machine operation, material handling and machine setup costs and maximising the machine utilisation. The proposed model is solved by a modified chaotic ant swarm simulation based optimisation (CAS2O) while applying pre-selection and discrete recombination operators is surveyed a capable method to simulate different experiments of FMS problems. A test problem is selected from the literature to evaluate the performance of the proposed approach. The results validate the effectiveness of the proposed method to solve the FMS scheduling problem. [ABSTRACT FROM AUTHOR]

Formal verification is an important means of tackling behavioural problems such as deadlocks in multi-agent systems. This paper is concerned with the role played by formal verification in the simulation-based performance analysis of multi-agent manufacturing systems. A discrete-event simulation case study is presented to show how varying certain timing parameters of the agent negotiation protocol affects the performance of a multi-agent manufacturing system as well as the chance of getting deadlocks among the software agents. When one tries to determine the optimal values of these timing parameters based on the simulation results, formal verification can help refine the results by confirming whether deadlocks among software agents are indeed possible for particular parameter values. This involves modelling the system's real-time behaviour according to the simulation model and applying the techniques and tools of model checking. [ABSTRACT FROM AUTHOR]

A car sequencing problem deals with the ordering of a list of vehicles to be produced on an assembly line so that the overall capacity of each work station is not exceeded. Some types of vehicles require several time-consuming operations to be done on a work station and will naturally overload that work station. Such vehicles are spaced out in the sequence, by means of a set of spacing constraints, in order to cope with the momentary increase of workload that they create. Two questions arise: which type of vehicles should be subject to the spacing constraints and by which distance should they be spaced out in the sequence. In practice as well as in the car sequencing literature, there does not exist a methodical way to answer the first question and the existing methods for the second one is no longer adequate due to the increased diversity of cars produced in an assembly line. In this paper, we propose two new methods to answer these questions with a special emphasis on the first one. The performance of the proposed methods is illustrated using a real case study. [ABSTRACT FROM AUTHOR]

Lean production is proved to be an effective tool for companies to improve continuously and is widely studied from both practical and theoretical perspectives. However, most previous studies of lean production are limited to internal operations of a company. The research in this paper aims to explain the relationship between electronic-enabled supply chain integration and the adoption of lean production. A theoretical model with six hypotheses was proposed based on the innovation diffusion theory (IDT). The model was empirically tested with data from 558 manufacturers. The results show that: (1) IDT can explain lean production adoption; and (2) electronic-enabled supply chain integration positively influences the perceived relative advantage of lean production and consequently leads to its long-term adoption. This study uses IDT to explain lean production adoption with the influence of electronic-enabled manufacturing supply chain (EMSC). The study also has a practical implication that may change the supply policy in future practices, as companies may require their suppliers to implement EMSC as part of the lean production requirements. [ABSTRACT FROM AUTHOR]

This paper addresses the problem of simultaneous scheduling of machines and two identical automated guided vehicles (AGVs) in a flexible manufacturing system (FMS). For solving this problem, a new meta-heuristic differential evolution (DE) algorithm is proposed. The problem consists of two interrelated problems, scheduling of machines and scheduling of AGVs. A simultaneous scheduling of these, in order to minimise the makespan will result in a FMS being able to complete all the jobs assigned to it at the earliest time possible, thus saving resources. An increase in the performance of the FMS under consideration would be expected as a result of making the scheduling of AGVs as an integral part of the overall scheduling activity. The algorithm is tested by using problems generated by various researchers and the makespan obtained by the algorithm is compared with that obtained by other researchers and analysed. [ABSTRACT FROM AUTHOR]

Mixed-model assembly lines are widely used in a range of production settings, such as the final assembly of the automotive and electronics industries, where they are applied to mass-produce standardised commodities. One of the greatest challenges when installing and reconfiguring these lines is the vast product variety modern mixed-model assembly lines have to cope with. Traditionally, product variety is bypassed during mid-term assembly line balancing by applying a joint precedence graph, which represents an (artificial) average model and serves as the input data for a single model assembly line balancing procedure. However, this procedure might lead to considerable variations in the station times, so that serious sequencing problems emerge and work overload threatens. To avoid these difficulties, different extensions of assembly line balancing for workload smoothing, i.e. horizontal balancing, have been introduced in the literature. This paper presents a multitude of known and yet unknown objectives for workload smoothing and systematically tests these measures in a comprehensive computational study. The results suggest that workload smoothing is an essential task in mixed-model assembly lines and that some (of the newly introduced) objectives are superior to others. [ABSTRACT FROM AUTHOR]

In this paper new analytical travel time models for the computation of cycle times for unit-load double-deep automated storage and retrieval systems (in continuation double-deep AS/RS) are presented. The proposed models consider the real operating characteristics of the storage and retrieval machine and the condition of rearranging blocking loads to the nearest free storage location during the retrieval process. With the assumption of the uniform distributed storage rack positions and the probability theory, the expressions of the single and modified dual command cycle have been determined. The proposed models enable the calculation of the mean cycle time for single and dual command cycles, from which the performance of the double-deep AS/RS can be evaluated. A simulation model of the selected double-deep AS/RS has been developed to compare the performances of the proposed analytical travel time models. The numerical analyses show that with regard to the examined type of double-deep AS/RS with a different fill-grade factor, the results of the proposed analytical travel time models correlate with the results of simulation models of double-deep AS/RS. [ABSTRACT FROM AUTHOR]

This paper presents new results for assessing the robustness of a configuration for multi-purpose machines. The workshop manager is provided with quantitative and meaningful information on how a configuration behaves when disturbances affect the demand. Thus, configurations can be compared on the basis of temporal performance, and also on robustness. The robustness measure of a configuration is returned by assessing the minimum magnitude of disturbances affecting the forecast demand that may lead to breaking the deadline provided by the decision-maker. First, it is shown how to minimise the completion time for a given demand. The demands such that the deadline can be met for a given configuration are then characterised, and two robustness measures for a configuration are also provided. The theoretical results are illustrated in detail using an application example. [ABSTRACT FROM AUTHOR]

Statistical quality control based approaches provide tools such as control charts for monitoring process parameters (usually 'physical layer') as well as rules such as the Western Electric Rules for detecting anomalies. The design of these charts is based on the statistical properties of the monitored parameters and the anomaly notification is related to the statistical significance of the observed change, the practical significance of the change, i.e. the sensitivity of system to the deviation in the parameter values, is not captured. Monitoring and alerting in the 'planning layers', however, is driven by the practical significance of the detected change as against the statistical significance. Recent developments in the field of supply chain event management have been focusing on providing tools and solutions for addressing these needs of the planning layers - these studies have, to a large extent been ad hoc. In this paper we propose and present parametric charts - a post-optimality-based approach for the design and implementation of monitoring and prioritising strategies for logistical anomalies. Analogous to the quality control charts, the parametric charts have four automatically generated regions, namely, the insensitive, the perturbation, the re-optimisation, and the infeasible, with each region having specific priorities and alarm levels associated with them. The bounds for the regions are based on the practical significance of the detected change as against the statistical significance of the deviation. The proposed approach offers three benefits: (1) it removes the ad hoc-ness associated with the determination of the practical significance as well as the priority given to the different classes of impacts that the system user observes, (2) the time consuming process of entering and fine-tuning the alarm bands and the priorities associated with the different alarm types when the exception analytics systems are installed can be decreased and automated, and (3) it aligns the exception analytics with the specific plans that are being executed. The step-by-step implementation of the charting approach is elucidated through a case study for the production unit at the FAME lab, at the Pennsylvania State University. [ABSTRACT FROM AUTHOR]

This paper considers the vehicle dispatching problem in large-scale overhead hoist transport (OHT) systems of semiconductor fabrication lines. We propose a Hungarian algorithm based OHT reassignment approach named HABOR. HABOR attempts to take advantage of simultaneous vehicle reassignment based on up-to-date system status using the formulation of the assignment problem. The effectiveness of HABOR is demonstrated using a sample OHT system of a semiconductor fabrication line with more than 130 vehicles, where the flow path of the line allows direct delivery so that an inter-bay wafer movement can be accomplished by a single vehicle without an intermediate storage step at a stocker. HABOR compares favorably with the shortest travel distance first rule and with the reassignment-based rule recently proposed by the authors. [ABSTRACT FROM AUTHOR]