Optimization of manufacturing processes is one of the key challenges towards a sustainable manufa... more Optimization of manufacturing processes is one of the key challenges towards a sustainable manufacturing environment. The components manufactured nowadays are usually divided into small batches of highly customized parts. These parts are usually machined using the traditional approach for machining on CNC machines. This approach involves the creation of a static G-code for every component that is manufactured, which is dispatched to the machines either manually or through a LAN network. In this paper a new approach in machine tool programming is presented. The proposed system is based on IEC 61499 function blocks to create last-minute feature based code for machining respecting actual machine status. The proposed system optimizes cutting parameters and delivers optimized code with respect to machining time. The function block approach is ideal for on-controller implementation while also allowing through its web based option the embedding into a cloud manufacturing environment. A clo...
The shift of traditional mass producing industries towards mass customisation practices is nowada... more The shift of traditional mass producing industries towards mass customisation practices is nowadays evident. However, if not implemented properly, mass customisation can lead to disturbances in material flow and severe reduction in productivity. This paper discusses the design and development of a Cloud-based production planning and control system for discrete manufacturing environments, referred to as i-MRP. The proposed approach takes into consideration capacity constraints, lot sizing and priority control in a ‘bucket-less’ manufacturing environment. The i-MRP system offers simultaneous shop scheduling and material planning, where material and capacity constraints are considered together in a continuous time environment. A number of feasible alternative shop schedules and material plan combinations are formed and are evaluated on the Cloud platform where the i-MRP engine is hosted. The Cloud platform enables mobility, since it is device and location independent, as well as it minimises the cost of IT infrastructure ownership, which is especially important for SMEs. The performance of the i-MRP system has been studied in an SME from the textile sector, using real production data. The system demonstrates high performance in cases of short production times, high value inventory and frequent, small deliveries by suppliers. The i-MRP can be easily integrated with legacy IT systems as an interfaced functional module under the Software as a Service (SaaS) architecture.
Advances in Sustainable and Competitive Manufacturing Systems, Lecture Notes in Mechanical Engineering, 2013
Manufacturers are nowadays highly affected by the ever-increasing number of product variants, und... more Manufacturers are nowadays highly affected by the ever-increasing number of product variants, under the product personalization trend. The large number of cooperating manufacturing network partners leads to enormous search spaces of alternative manufacturing network configurations. This obstructs effective decision-making towards configuring efficient network structures, a nonetheless crucial decision for a company. Exact methods guarantee that the identified solution is the optimum, with regards to the objectives set in the specified problem. However, in real life cases the magnitude of the solution space is such that these methods cannot be utilized due to computational constraints. For tackling such NP-hard problems, meta-heuristics can be utilized that provide a trade-off between the quality of solution and the computation time. This research work describes the modeling and solving of a manufacturing network design problem using the metaheuristic methods of simulated annealing and tabu search. The quality of the results identified by these methods is compared with the results obtained from an intelligent search algorithm and an exhaustive enumerative method, which are implemented into a web-based platform for the design and planning of manufacturing networks. The approach is validated through its application to a real life case study with data acquired from the automotive industry.
Advances in Production Management Systems (APMS 2012), 2013
This paper presents a method for the design and evaluation of manufacturing networks focused on t... more This paper presents a method for the design and evaluation of manufacturing networks focused on the production of personalised goods. The method, which is implemented to a software tool, comprises of a mechanism for the generation and evaluation of manufacturing network alternative configurations. An exhaustive search and an intelligent search algorithm are developed, for the identification of efficient manufacturing network designs. Multiple conflicting user-defined criteria are used in the evaluation, including cost, time, CO2 emissions, energy consumption and quality. Discrete Event Simulation models of manufacturing networks are simulated against a demand profile. Performance indicators of flexibility, throughput and work-in-process are calculated through simulation and are used for assessing the performance of centralised and decentralised networks. The results obtained through the exhaustive and intelligent search methods are compared. The applicability of the method is tested on a real- life industrial pilot case, utilising data from an automotive manufacturer.
Design and Management of Lean Production Systems, 2014
The transition from local economies to the global competitive landscape and the current fluctuati... more The transition from local economies to the global competitive landscape and the current fluctuating customer demands drives a never-ending transformation of manufacturing systems. In combination with prominent technological advances and other socio-political reasons of each era, such changes led to the evolution of manufacturing paradigms systems from craftsmanship to automation and decentralisation. This transition created the necessity for new means of designing, planning, and controlling manufacturing companies and networks. In production early stages, manufacturing was viewed as a functional area. On the other hand, current production paradigms are based on the customer focus and view manufacturing as an enterprise. This major diversification led to the gradual reorganisation of manufacturing systems in order to achieve mass customisation of typically mass-produced products. The purpose of this chapter is to specify the evolution of manufacturing paradigms, their basic principles, and the links among them. A discussion on future trends of manufacturing paradigms derives from the review and is finally presented.
During the design phase of large-scale industrial engineering projects, numerous problems usually... more During the design phase of large-scale industrial engineering projects, numerous problems usually arise, which are related to the project analysis and methods used in each phase. Such projects are undertaken by multi-disciplinary teams of expert designers and planning managers that often communicate these problems to the members of their team via emails and telephone calls. However, the alignment of efforts towards solving these problems cannot be achieved effectively though these inherently limited communication and collaboration means. In parallel, the operation of manufacturing systems is evolving towards structures that are similar to social networks. The trend is to automatically connect to web-based collaboration platforms in order to search for the appropriate experts to deal with the problem in question. Towards this end, the proposed research work focuses on the development of a knowledge-based method, which is developed into a mobile app, and focuses on providing a collaboration space for reporting, tracking, and solving project-related problems. The methodology adopts concepts from the Root Cause Analysis method, which is further enriched with knowledge reuse features. Already reported and potentially solved problems, as well as other historical data are retrieved from a knowledge repository through advanced indexing techniques in order to support the identification of solutions for newly experienced problems. Results from the interpretation of the natural language that is considered to be used in the problem reporting phase and the accuracy of retrieved solutions are further discussed. Finally, the methodology is validated through a real-life case study obtained from the die construction department of an automotive industry.
Proceeding of the IFIP WG 5.7 International Conference on Advances in Production Management Systems, APMS (2014), 2014
Efficient design of manufacturing networks is paramount for a sustainable growth. The establishme... more Efficient design of manufacturing networks is paramount for a sustainable growth. The establishment of mass customization and the transition to personalization complicates design activities and leads to vast amounts of unexploited data. This research work aims to exploit existing knowledge for enhancing decision-making during the initial manufacturing networks design, which carry out custom orders of industrial equipment. A method developed into software is proposed, comprising a Genetic Algorithm with knowledge-enriched operators and an intelligent initialization algorithm that exploits existing planning knowledge. The validation of the method is performed using data from a high-precision mold-making manufacturer and its network of first-tier suppliers.
Contemporary shop-floors are highly affected by the ever-increasing complexity that is caused by ... more Contemporary shop-floors are highly affected by the ever-increasing complexity that is caused by the fluctuating customer demands. Therefore, a high degree of flexibility is needed and the scheduling of manufacturing tasks must be agile to changes. For addressing this challenge, this research work proposes a knowledge enriched short-term job-shop scheduling engine. More precisely, it focuses on the short-term scheduling of the resources of the machine shop, through an artificial intelligence algorithm that generates and evaluates alternative assignments of resources to tasks. Based on the requirements of a new order, a similarity mechanism retrieves successfully executed past orders together with a dataset that includes the processing times, the job and task sequence and the suitable resources. Afterwards it adapts these parameters to the requirements of the new order so as to evaluate the alternative schedules and identify a good alternative in a timely manner. The deriving schedule can be presented on mobile devices and it can be manipulated by the planner on-the-fly respecting tasks precedence constraints and machine availability. A case study from the mold making industry is used for validating the proposed framework.
Manufacturers and service providers are called to design, plan and operate globalized manufacturi... more Manufacturers and service providers are called to design, plan and operate globalized manufacturing networks, addressing to challenges such as ever-decreasing lifecycles and increased product complexity. These factors, caused primarily by mass customisation and demand volatility, generate a number of issues related to the design and planning of manufacturing systems and networks, which are not holistically tackled in industrial and academic practices. The mapping of production performance requirements to process and production planning requires automated closed-loop control systems, which current systems fail to deliver. Technology-based business approaches are an enabler for increased enterprise performance. Towards that end, the issues discussed in this paper focus on challenges in the design and planning of manufacturing networks in a mass customization and personalization landscape. The development of methods and tools for supporting the dynamic configuration and optimal routing of manufacturing networks and facilities under cost, time, complexity and environmental constraints to support product-service personalization are promoted.
Product complexity leads to increased unpredictability of indices related to manufacturing perfor... more Product complexity leads to increased unpredictability of indices related to manufacturing performance estimation. This phenomenon is intensified in companies that produce engineered-to-order products, such as the knowledge and labour intensive mould-making industry. During the initial capturing of product specifications formalisation difficulties arise. Moreover, the estimation of delivery times for new moulding project is solely based on the engineers’ experience. A methodology, which has been developed into a software tool is proposed that exposes graphical interfaces for customers to submit new orders and establish a formalised communication with the engineering team. The collected data are stored in a knowledge repository and are processed by a case-based reasoning mechanism for the lead time estimation. A real-life pilot installation has been initiated to a mould making SME. Preliminary results depict a significant reduction in the number of iterations between customers and engineering department compared to the traditional approach followed by the company, and improved accuracy of lead time estimation.
8th ASME 2014 International Manufacturing Science and Engineering Conference, 2014
Optimization of manufacturing processes is one of the key challenges towards a sustainable manufa... more Optimization of manufacturing processes is one of the key challenges towards a sustainable manufacturing environment. The components manufactured nowadays are usually divided into small batches of highly customized parts. These parts are usually machined using the traditional approach for machining on CNC machines. This approach involves the creation of a static G-code for every component that is manufactured, which is dispatched to the machines either manually or through a LAN network. In this paper a new approach in machine tool programming is presented. The proposed system is based on IEC 61499 function blocks to create last-minute feature based code for machining respecting actual machine status. The proposed system optimizes cutting parameters and delivers optimized code with respect to machining time. The function block approach is ideal for on-controller implementation while also allowing through its web based option the embedding into a cloud manufacturing environment. A cloud platform accommodates the machine availability monitoring module for increasing shop-floor awareness and allowing for the correct decisions at the right time. The machining process of face milling was selected as a case study for demonstrating the functionality of the proposed system. The results of the case study are visualized and verified using simulation software
8th International Conference on Digital Enterprise Technology - DET 2014, 2014
Although the market started expressing the need for high product variety three decades ago, manuf... more Although the market started expressing the need for high product variety three decades ago, manufacturing systems have not kept the pace with these social and economic developments. Modern industrial shop-floors are highly affected by the ever-increasing product variety and volatile market demands introduced by the currently established mass customisation paradigm. The increasing complexity and high unpredictability in manufacturing activities require immediate reactions to emerging disturbances, such us reducing bottlenecks, and avoiding brake-downs and idleness of critical equipment in order to increase productivity and therefore, the company’s competitiveness. The framework proposed in this research work includes machine monitoring techniques for the near real-time identification of machine status, in order to allow a predictive maintenance engine to diminish machine tool failures. Moreover, an adaptive short-term scheduling mechanism is employed, using monitoring data for the refinement of production schedules based on the current and future conditions of the shop-floor. Data acquired from a multi-sensory pilot installation together with information directly retrieved from the machine tool’s controller are fused and comprise the input to subsequent software modules. The monitoring module is described, which analyses sensory data during the machine operation, as well as the Adaptive Scheduling Engine that dispatches schedules and refines future schedules based on awareness regarding machine availability. The software architecture and hardware setups are described and comprise the roadmap for the framework development. A possible application of the framework is described in the context of a European SME manufacturer.
47th CIRP Conference on Manufacturing Systems, 2014
The importance of leveraging manufacturing teaching and training up to the standards of the curre... more The importance of leveraging manufacturing teaching and training up to the standards of the current and future needs is obvious. Recent studies have pointed out the urgent need for future engineers and knowledge workers to adopt teaching curricula in order to be prepared to cope with the increasing industrial requirements of the factories of the future. The current study presents the evolution of the Teaching Factory concept and its application to a real-life pilot. The Teaching Factory paradigm comprises the industrial project, the relevant educational approach and the necessary ICT configuration for the facilitation of interaction between industry and academia. The current status of the paradigm is tested on a real-life pilot, between a university and a construction equipment factory. The conclusions of the pilot, show the promising nature of the Teaching Factory and the numerous benefits accruing, both for academia and industry.
47th CIRP Conference on Manufacturing Systems, 2014
Product complexity leads to increased unpredictability of indices related to manufacturing perfor... more Product complexity leads to increased unpredictability of indices related to manufacturing performance estimation. This phenomenon is intensified in companies that produce engineered-to-order products, such as the knowledge and labour intensive mould-making industry. During the initial capturing of product specifications formalisation difficulties arise. Moreover, the estimation of delivery times for new moulding project is solely based on the engineers’ experience. A methodology, which has been developed into a software tool is proposed that exposes graphical interfaces for customers to submit new orders and establish a formalised communication with the engineering team. The collected data are stored in a knowledge repository and are processed by a case-based reasoning mechanism for the lead time estimation. A real-life pilot installation has been initiated to a mould making SME. Preliminary results depict a significant reduction in the number of iterations between customers and engineering department compared to the traditional approach followed by the company, and improved accuracy of lead time estimation.
8th International Conference on Digital Enterprise Technology - DET 2014, 2014
Simulation comprises an indispensable set of technological tools and methods for the successful i... more Simulation comprises an indispensable set of technological tools and methods for the successful implementation of digital manufacturing, since it allows for the experimentation and validation of product, process and system design and configuration. Especially in todays’ turbulent manufacturing environment, which is affected by megatrends such as globalisation and ever-increasing requirements for higher degree of product customisation and personalisation, the value of simulation is evident. This keynote paper investigates the major milestones in the evolution of simulation technologies and examines recent industrial and research applications and findings. Based on this review, the identification of gaps in current practices is presented, and future trends and challenges to be met on the field are outlined. The considered simulation methods and tools include CAx, Factory layout design, Material and Information flow design, Manufacturing Networks Design, Manufacturing Systems Planning and Control, Manufacturing Networks Planning and Control, Augmented and Virtual Reality in product and process design, planning and verification (ergonomics, robotics, etc.). The evolution, advances, current practices and future trends of these technologies, industrial applications and research results are discussed in the context of the contemporary manufacturing industry.
45th CIRP Conference on Manufacturing Systems, 2012
In today’s highly customer-oriented market, web-based approaches are the main enablers towards ac... more In today’s highly customer-oriented market, web-based approaches are the main enablers towards achieving a sufficient level of customer involvement during the design phase of new products. This research work, describes a novel software architecture that facilitates the ability to visualise and manipulate three-dimensional product design parameters under constraints. The manipulation is performed in real-time, over web, comprising Virtual and Augmented Reality functionalities. The approach integrates the customer into the supply chain of the personalised product manufacturing, as the design changes have a direct impact on the supply chain configuration. The software architecture and the description of the offered functionalities are presented, as well as the implementation tools and programming frameworks. The approach is tested on a case study from the automotive sector.
46th CIRP Conference on Manufacturing Systems, 2013
The volatile globalised markets and mass customisation greatly affect modern industries. In this ... more The volatile globalised markets and mass customisation greatly affect modern industries. In this context, the timely and accurate manufacturing network design is an important strategic decision. However, this proven NP-hard problem cannot be approached by exhaustive methods. This research work aims to support the decision-makers by introducing a Genetic Algorithm for the identification of near optimum manufacturing network configurations. The examined problem tackles the multi-stage manufacturing network design for single customised products, through satisfaction of multiple objectives. The performance of the alternative designs deriving from the GA is compared to the results of an intelligent search algorithm with adjustable control parameters, and with an exhaustive search method. The conflicting criteria for evaluating the alternative configurations include cost, time, quality and environmental parameters. The applicability of the proposed method is validated through a case study, utilising data acquired from the automotive sector.
45th CIRP Conference on Manufacturing Systems, 2012
In today’s era of customer-driven markets, manufacturers throughout the globe realize that the ef... more In today’s era of customer-driven markets, manufacturers throughout the globe realize that the efficient collaboration with their supply chain partners is amongst the most crucial factors for improved profits. The necessity to coordinate the activities of the independent partners and to align their objectives towards a common goal is evident. This research work, presents a methodology for the identification of efficient supply chain schemes in decentralised and centralised manufacturing environments. The methodology allows the generation of feasible alternative production and transportation schemes, using exhaustive and intelligent search methods. The schemes are evaluated against multiple user-defined criteria such as cost, time, environmental impact and quality. The derived alternatives can be used for the planning and coordination of geographically dispersed facilities that carry out the production of highly customized products. The approach is implemented to a tool and is applied on an automotive case study.
Lecture Notes in Production Engineering,Proceedings of the CIRP Sponsored Conference RoMaC 2012, 2012
During the last three decades the economic landscape has abandoned its local characteristics and ... more During the last three decades the economic landscape has abandoned its local characteristics and evolved into a global and highly competitive economy. The market demands towards high product variety, the low human labour costs in specific locations, the evolution of Information and Communication Technologies, and specific social and political forces are the principal reasons towards globalization. The main trend currently outlining the development of manufacturing paradigms is the ever-increasing tendency in the direction of decentralization of manufacturing functions towards decentralized entities. This has caused a fundamental reorganization process of the manufacturing organizations in order to cope with this trend. Several critical issues rise in the control and management of such organizations. These criticalities are further compounded by the need to achieve mass customization of industrial products, as this greatly complicates the manufacturing and supply activities. Moreover, the modalities for the configuration and implementation of each of the distributed manufacturing typologies are identified. The purpose of this paper is to specify the main trends, issues, and sensitive topics that characterize the behaviour and performance of these production systems. Based on this review, a discussion over existing production concepts is performed.
Lecture Notes in Production Engineering,Proceedings of the CIRP Sponsored Conference RoMaC 2012, 2012
The current trend of globalisation and decentralisation of the production activities has created ... more The current trend of globalisation and decentralisation of the production activities has created a series of environment related issues. The increase of transportation distances, the escalated consumption of natural resources, and toxic emissions are among the generated challenges. Additionally, the manufacturing complexity, due to high product variety leads to increased energy consumption. Nevertheless, natural resources are limited and emission levels must be kept under the limits. This paper presents a methodology, implemented through a software tool, for the investigation of the environmental impact caused by centralised and decentralised manufacturing networks, under heavy product customisation. Simulation models of automotive manufacturing networks were developed, utilising real life industrial data, for the investigation of the impact of the production networks under highly diversified product demand, on environmental aspects. Multiple user-defined criteria have been used for the evaluation of the environmental footprint, including CO2 emissions and energy requirements in terms of depletion of natural resources. This paper aims at identifying optimal configurations of centralised and decentralised production networks, characterised by reduced energy requirements, low consumption of natural resources and reduced toxic emissions.
Optimization of manufacturing processes is one of the key challenges towards a sustainable manufa... more Optimization of manufacturing processes is one of the key challenges towards a sustainable manufacturing environment. The components manufactured nowadays are usually divided into small batches of highly customized parts. These parts are usually machined using the traditional approach for machining on CNC machines. This approach involves the creation of a static G-code for every component that is manufactured, which is dispatched to the machines either manually or through a LAN network. In this paper a new approach in machine tool programming is presented. The proposed system is based on IEC 61499 function blocks to create last-minute feature based code for machining respecting actual machine status. The proposed system optimizes cutting parameters and delivers optimized code with respect to machining time. The function block approach is ideal for on-controller implementation while also allowing through its web based option the embedding into a cloud manufacturing environment. A clo...
The shift of traditional mass producing industries towards mass customisation practices is nowada... more The shift of traditional mass producing industries towards mass customisation practices is nowadays evident. However, if not implemented properly, mass customisation can lead to disturbances in material flow and severe reduction in productivity. This paper discusses the design and development of a Cloud-based production planning and control system for discrete manufacturing environments, referred to as i-MRP. The proposed approach takes into consideration capacity constraints, lot sizing and priority control in a ‘bucket-less’ manufacturing environment. The i-MRP system offers simultaneous shop scheduling and material planning, where material and capacity constraints are considered together in a continuous time environment. A number of feasible alternative shop schedules and material plan combinations are formed and are evaluated on the Cloud platform where the i-MRP engine is hosted. The Cloud platform enables mobility, since it is device and location independent, as well as it minimises the cost of IT infrastructure ownership, which is especially important for SMEs. The performance of the i-MRP system has been studied in an SME from the textile sector, using real production data. The system demonstrates high performance in cases of short production times, high value inventory and frequent, small deliveries by suppliers. The i-MRP can be easily integrated with legacy IT systems as an interfaced functional module under the Software as a Service (SaaS) architecture.
Advances in Sustainable and Competitive Manufacturing Systems, Lecture Notes in Mechanical Engineering, 2013
Manufacturers are nowadays highly affected by the ever-increasing number of product variants, und... more Manufacturers are nowadays highly affected by the ever-increasing number of product variants, under the product personalization trend. The large number of cooperating manufacturing network partners leads to enormous search spaces of alternative manufacturing network configurations. This obstructs effective decision-making towards configuring efficient network structures, a nonetheless crucial decision for a company. Exact methods guarantee that the identified solution is the optimum, with regards to the objectives set in the specified problem. However, in real life cases the magnitude of the solution space is such that these methods cannot be utilized due to computational constraints. For tackling such NP-hard problems, meta-heuristics can be utilized that provide a trade-off between the quality of solution and the computation time. This research work describes the modeling and solving of a manufacturing network design problem using the metaheuristic methods of simulated annealing and tabu search. The quality of the results identified by these methods is compared with the results obtained from an intelligent search algorithm and an exhaustive enumerative method, which are implemented into a web-based platform for the design and planning of manufacturing networks. The approach is validated through its application to a real life case study with data acquired from the automotive industry.
Advances in Production Management Systems (APMS 2012), 2013
This paper presents a method for the design and evaluation of manufacturing networks focused on t... more This paper presents a method for the design and evaluation of manufacturing networks focused on the production of personalised goods. The method, which is implemented to a software tool, comprises of a mechanism for the generation and evaluation of manufacturing network alternative configurations. An exhaustive search and an intelligent search algorithm are developed, for the identification of efficient manufacturing network designs. Multiple conflicting user-defined criteria are used in the evaluation, including cost, time, CO2 emissions, energy consumption and quality. Discrete Event Simulation models of manufacturing networks are simulated against a demand profile. Performance indicators of flexibility, throughput and work-in-process are calculated through simulation and are used for assessing the performance of centralised and decentralised networks. The results obtained through the exhaustive and intelligent search methods are compared. The applicability of the method is tested on a real- life industrial pilot case, utilising data from an automotive manufacturer.
Design and Management of Lean Production Systems, 2014
The transition from local economies to the global competitive landscape and the current fluctuati... more The transition from local economies to the global competitive landscape and the current fluctuating customer demands drives a never-ending transformation of manufacturing systems. In combination with prominent technological advances and other socio-political reasons of each era, such changes led to the evolution of manufacturing paradigms systems from craftsmanship to automation and decentralisation. This transition created the necessity for new means of designing, planning, and controlling manufacturing companies and networks. In production early stages, manufacturing was viewed as a functional area. On the other hand, current production paradigms are based on the customer focus and view manufacturing as an enterprise. This major diversification led to the gradual reorganisation of manufacturing systems in order to achieve mass customisation of typically mass-produced products. The purpose of this chapter is to specify the evolution of manufacturing paradigms, their basic principles, and the links among them. A discussion on future trends of manufacturing paradigms derives from the review and is finally presented.
During the design phase of large-scale industrial engineering projects, numerous problems usually... more During the design phase of large-scale industrial engineering projects, numerous problems usually arise, which are related to the project analysis and methods used in each phase. Such projects are undertaken by multi-disciplinary teams of expert designers and planning managers that often communicate these problems to the members of their team via emails and telephone calls. However, the alignment of efforts towards solving these problems cannot be achieved effectively though these inherently limited communication and collaboration means. In parallel, the operation of manufacturing systems is evolving towards structures that are similar to social networks. The trend is to automatically connect to web-based collaboration platforms in order to search for the appropriate experts to deal with the problem in question. Towards this end, the proposed research work focuses on the development of a knowledge-based method, which is developed into a mobile app, and focuses on providing a collaboration space for reporting, tracking, and solving project-related problems. The methodology adopts concepts from the Root Cause Analysis method, which is further enriched with knowledge reuse features. Already reported and potentially solved problems, as well as other historical data are retrieved from a knowledge repository through advanced indexing techniques in order to support the identification of solutions for newly experienced problems. Results from the interpretation of the natural language that is considered to be used in the problem reporting phase and the accuracy of retrieved solutions are further discussed. Finally, the methodology is validated through a real-life case study obtained from the die construction department of an automotive industry.
Proceeding of the IFIP WG 5.7 International Conference on Advances in Production Management Systems, APMS (2014), 2014
Efficient design of manufacturing networks is paramount for a sustainable growth. The establishme... more Efficient design of manufacturing networks is paramount for a sustainable growth. The establishment of mass customization and the transition to personalization complicates design activities and leads to vast amounts of unexploited data. This research work aims to exploit existing knowledge for enhancing decision-making during the initial manufacturing networks design, which carry out custom orders of industrial equipment. A method developed into software is proposed, comprising a Genetic Algorithm with knowledge-enriched operators and an intelligent initialization algorithm that exploits existing planning knowledge. The validation of the method is performed using data from a high-precision mold-making manufacturer and its network of first-tier suppliers.
Contemporary shop-floors are highly affected by the ever-increasing complexity that is caused by ... more Contemporary shop-floors are highly affected by the ever-increasing complexity that is caused by the fluctuating customer demands. Therefore, a high degree of flexibility is needed and the scheduling of manufacturing tasks must be agile to changes. For addressing this challenge, this research work proposes a knowledge enriched short-term job-shop scheduling engine. More precisely, it focuses on the short-term scheduling of the resources of the machine shop, through an artificial intelligence algorithm that generates and evaluates alternative assignments of resources to tasks. Based on the requirements of a new order, a similarity mechanism retrieves successfully executed past orders together with a dataset that includes the processing times, the job and task sequence and the suitable resources. Afterwards it adapts these parameters to the requirements of the new order so as to evaluate the alternative schedules and identify a good alternative in a timely manner. The deriving schedule can be presented on mobile devices and it can be manipulated by the planner on-the-fly respecting tasks precedence constraints and machine availability. A case study from the mold making industry is used for validating the proposed framework.
Manufacturers and service providers are called to design, plan and operate globalized manufacturi... more Manufacturers and service providers are called to design, plan and operate globalized manufacturing networks, addressing to challenges such as ever-decreasing lifecycles and increased product complexity. These factors, caused primarily by mass customisation and demand volatility, generate a number of issues related to the design and planning of manufacturing systems and networks, which are not holistically tackled in industrial and academic practices. The mapping of production performance requirements to process and production planning requires automated closed-loop control systems, which current systems fail to deliver. Technology-based business approaches are an enabler for increased enterprise performance. Towards that end, the issues discussed in this paper focus on challenges in the design and planning of manufacturing networks in a mass customization and personalization landscape. The development of methods and tools for supporting the dynamic configuration and optimal routing of manufacturing networks and facilities under cost, time, complexity and environmental constraints to support product-service personalization are promoted.
Product complexity leads to increased unpredictability of indices related to manufacturing perfor... more Product complexity leads to increased unpredictability of indices related to manufacturing performance estimation. This phenomenon is intensified in companies that produce engineered-to-order products, such as the knowledge and labour intensive mould-making industry. During the initial capturing of product specifications formalisation difficulties arise. Moreover, the estimation of delivery times for new moulding project is solely based on the engineers’ experience. A methodology, which has been developed into a software tool is proposed that exposes graphical interfaces for customers to submit new orders and establish a formalised communication with the engineering team. The collected data are stored in a knowledge repository and are processed by a case-based reasoning mechanism for the lead time estimation. A real-life pilot installation has been initiated to a mould making SME. Preliminary results depict a significant reduction in the number of iterations between customers and engineering department compared to the traditional approach followed by the company, and improved accuracy of lead time estimation.
8th ASME 2014 International Manufacturing Science and Engineering Conference, 2014
Optimization of manufacturing processes is one of the key challenges towards a sustainable manufa... more Optimization of manufacturing processes is one of the key challenges towards a sustainable manufacturing environment. The components manufactured nowadays are usually divided into small batches of highly customized parts. These parts are usually machined using the traditional approach for machining on CNC machines. This approach involves the creation of a static G-code for every component that is manufactured, which is dispatched to the machines either manually or through a LAN network. In this paper a new approach in machine tool programming is presented. The proposed system is based on IEC 61499 function blocks to create last-minute feature based code for machining respecting actual machine status. The proposed system optimizes cutting parameters and delivers optimized code with respect to machining time. The function block approach is ideal for on-controller implementation while also allowing through its web based option the embedding into a cloud manufacturing environment. A cloud platform accommodates the machine availability monitoring module for increasing shop-floor awareness and allowing for the correct decisions at the right time. The machining process of face milling was selected as a case study for demonstrating the functionality of the proposed system. The results of the case study are visualized and verified using simulation software
8th International Conference on Digital Enterprise Technology - DET 2014, 2014
Although the market started expressing the need for high product variety three decades ago, manuf... more Although the market started expressing the need for high product variety three decades ago, manufacturing systems have not kept the pace with these social and economic developments. Modern industrial shop-floors are highly affected by the ever-increasing product variety and volatile market demands introduced by the currently established mass customisation paradigm. The increasing complexity and high unpredictability in manufacturing activities require immediate reactions to emerging disturbances, such us reducing bottlenecks, and avoiding brake-downs and idleness of critical equipment in order to increase productivity and therefore, the company’s competitiveness. The framework proposed in this research work includes machine monitoring techniques for the near real-time identification of machine status, in order to allow a predictive maintenance engine to diminish machine tool failures. Moreover, an adaptive short-term scheduling mechanism is employed, using monitoring data for the refinement of production schedules based on the current and future conditions of the shop-floor. Data acquired from a multi-sensory pilot installation together with information directly retrieved from the machine tool’s controller are fused and comprise the input to subsequent software modules. The monitoring module is described, which analyses sensory data during the machine operation, as well as the Adaptive Scheduling Engine that dispatches schedules and refines future schedules based on awareness regarding machine availability. The software architecture and hardware setups are described and comprise the roadmap for the framework development. A possible application of the framework is described in the context of a European SME manufacturer.
47th CIRP Conference on Manufacturing Systems, 2014
The importance of leveraging manufacturing teaching and training up to the standards of the curre... more The importance of leveraging manufacturing teaching and training up to the standards of the current and future needs is obvious. Recent studies have pointed out the urgent need for future engineers and knowledge workers to adopt teaching curricula in order to be prepared to cope with the increasing industrial requirements of the factories of the future. The current study presents the evolution of the Teaching Factory concept and its application to a real-life pilot. The Teaching Factory paradigm comprises the industrial project, the relevant educational approach and the necessary ICT configuration for the facilitation of interaction between industry and academia. The current status of the paradigm is tested on a real-life pilot, between a university and a construction equipment factory. The conclusions of the pilot, show the promising nature of the Teaching Factory and the numerous benefits accruing, both for academia and industry.
47th CIRP Conference on Manufacturing Systems, 2014
Product complexity leads to increased unpredictability of indices related to manufacturing perfor... more Product complexity leads to increased unpredictability of indices related to manufacturing performance estimation. This phenomenon is intensified in companies that produce engineered-to-order products, such as the knowledge and labour intensive mould-making industry. During the initial capturing of product specifications formalisation difficulties arise. Moreover, the estimation of delivery times for new moulding project is solely based on the engineers’ experience. A methodology, which has been developed into a software tool is proposed that exposes graphical interfaces for customers to submit new orders and establish a formalised communication with the engineering team. The collected data are stored in a knowledge repository and are processed by a case-based reasoning mechanism for the lead time estimation. A real-life pilot installation has been initiated to a mould making SME. Preliminary results depict a significant reduction in the number of iterations between customers and engineering department compared to the traditional approach followed by the company, and improved accuracy of lead time estimation.
8th International Conference on Digital Enterprise Technology - DET 2014, 2014
Simulation comprises an indispensable set of technological tools and methods for the successful i... more Simulation comprises an indispensable set of technological tools and methods for the successful implementation of digital manufacturing, since it allows for the experimentation and validation of product, process and system design and configuration. Especially in todays’ turbulent manufacturing environment, which is affected by megatrends such as globalisation and ever-increasing requirements for higher degree of product customisation and personalisation, the value of simulation is evident. This keynote paper investigates the major milestones in the evolution of simulation technologies and examines recent industrial and research applications and findings. Based on this review, the identification of gaps in current practices is presented, and future trends and challenges to be met on the field are outlined. The considered simulation methods and tools include CAx, Factory layout design, Material and Information flow design, Manufacturing Networks Design, Manufacturing Systems Planning and Control, Manufacturing Networks Planning and Control, Augmented and Virtual Reality in product and process design, planning and verification (ergonomics, robotics, etc.). The evolution, advances, current practices and future trends of these technologies, industrial applications and research results are discussed in the context of the contemporary manufacturing industry.
45th CIRP Conference on Manufacturing Systems, 2012
In today’s highly customer-oriented market, web-based approaches are the main enablers towards ac... more In today’s highly customer-oriented market, web-based approaches are the main enablers towards achieving a sufficient level of customer involvement during the design phase of new products. This research work, describes a novel software architecture that facilitates the ability to visualise and manipulate three-dimensional product design parameters under constraints. The manipulation is performed in real-time, over web, comprising Virtual and Augmented Reality functionalities. The approach integrates the customer into the supply chain of the personalised product manufacturing, as the design changes have a direct impact on the supply chain configuration. The software architecture and the description of the offered functionalities are presented, as well as the implementation tools and programming frameworks. The approach is tested on a case study from the automotive sector.
46th CIRP Conference on Manufacturing Systems, 2013
The volatile globalised markets and mass customisation greatly affect modern industries. In this ... more The volatile globalised markets and mass customisation greatly affect modern industries. In this context, the timely and accurate manufacturing network design is an important strategic decision. However, this proven NP-hard problem cannot be approached by exhaustive methods. This research work aims to support the decision-makers by introducing a Genetic Algorithm for the identification of near optimum manufacturing network configurations. The examined problem tackles the multi-stage manufacturing network design for single customised products, through satisfaction of multiple objectives. The performance of the alternative designs deriving from the GA is compared to the results of an intelligent search algorithm with adjustable control parameters, and with an exhaustive search method. The conflicting criteria for evaluating the alternative configurations include cost, time, quality and environmental parameters. The applicability of the proposed method is validated through a case study, utilising data acquired from the automotive sector.
45th CIRP Conference on Manufacturing Systems, 2012
In today’s era of customer-driven markets, manufacturers throughout the globe realize that the ef... more In today’s era of customer-driven markets, manufacturers throughout the globe realize that the efficient collaboration with their supply chain partners is amongst the most crucial factors for improved profits. The necessity to coordinate the activities of the independent partners and to align their objectives towards a common goal is evident. This research work, presents a methodology for the identification of efficient supply chain schemes in decentralised and centralised manufacturing environments. The methodology allows the generation of feasible alternative production and transportation schemes, using exhaustive and intelligent search methods. The schemes are evaluated against multiple user-defined criteria such as cost, time, environmental impact and quality. The derived alternatives can be used for the planning and coordination of geographically dispersed facilities that carry out the production of highly customized products. The approach is implemented to a tool and is applied on an automotive case study.
Lecture Notes in Production Engineering,Proceedings of the CIRP Sponsored Conference RoMaC 2012, 2012
During the last three decades the economic landscape has abandoned its local characteristics and ... more During the last three decades the economic landscape has abandoned its local characteristics and evolved into a global and highly competitive economy. The market demands towards high product variety, the low human labour costs in specific locations, the evolution of Information and Communication Technologies, and specific social and political forces are the principal reasons towards globalization. The main trend currently outlining the development of manufacturing paradigms is the ever-increasing tendency in the direction of decentralization of manufacturing functions towards decentralized entities. This has caused a fundamental reorganization process of the manufacturing organizations in order to cope with this trend. Several critical issues rise in the control and management of such organizations. These criticalities are further compounded by the need to achieve mass customization of industrial products, as this greatly complicates the manufacturing and supply activities. Moreover, the modalities for the configuration and implementation of each of the distributed manufacturing typologies are identified. The purpose of this paper is to specify the main trends, issues, and sensitive topics that characterize the behaviour and performance of these production systems. Based on this review, a discussion over existing production concepts is performed.
Lecture Notes in Production Engineering,Proceedings of the CIRP Sponsored Conference RoMaC 2012, 2012
The current trend of globalisation and decentralisation of the production activities has created ... more The current trend of globalisation and decentralisation of the production activities has created a series of environment related issues. The increase of transportation distances, the escalated consumption of natural resources, and toxic emissions are among the generated challenges. Additionally, the manufacturing complexity, due to high product variety leads to increased energy consumption. Nevertheless, natural resources are limited and emission levels must be kept under the limits. This paper presents a methodology, implemented through a software tool, for the investigation of the environmental impact caused by centralised and decentralised manufacturing networks, under heavy product customisation. Simulation models of automotive manufacturing networks were developed, utilising real life industrial data, for the investigation of the impact of the production networks under highly diversified product demand, on environmental aspects. Multiple user-defined criteria have been used for the evaluation of the environmental footprint, including CO2 emissions and energy requirements in terms of depletion of natural resources. This paper aims at identifying optimal configurations of centralised and decentralised production networks, characterised by reduced energy requirements, low consumption of natural resources and reduced toxic emissions.
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Papers by Michael Doukas