Flexible Manufacturing Facility Research Articles

DP-FMEA: An innovative Failure Mode and Effects Analysis for distributed manufacturing processes

The Failure Mode and Effects Analysis (FMEA) is a powerful tool to design and maintain reliable systems (products, services or manufacturing processes), investigating their potential failure modes from the threefold perspective of severity, occurrence and detection. The Process FMEA, or more briefly P-FMEA, is a declination of the FMEA for manufacturing processes (or parts of them). Being progressively characterized by decentralized networks of flexible manufacturing facilities, the current scenario significantly hampers the implementation of the traditional P-FMEA, which requires the joint work of a group of experts formulating collective judgments. This paper revises the traditional P-FMEA approach and integrates it with the ZMII-technique – i.e. a recent aggregation technique based on the combination of the Thurstone’s Law of Comparative Judgment and the Generalized Least Squares method – allowing experts distributed through organizations to formulate their judgments individually. The revised approach – referred to as “distributed-Process FMEA” or more briefly dP-FMEA – allows to manage a number of experts, without requiring them to physically meet and formulate collective decisions, thus overcoming a relevant limitation of the traditional P-FMEA. The dP-FMEA approach also includes a relatively versatile response mode and overcomes several other limitations of the traditional approach, including but not limited to: (i) arbitrary formulation and aggregation of expert judgments, (ii) lack of consideration of the dispersion of these judgments, and (iii) lack of estimation of the uncertainty of results. The description is supported by a real-life application example concerning a plastic injection-molding process.

Strategic development of flexible manufacturing facilities

PurposeThis article addresses the lack of formal design guidance that supports flexibility within the architectural and engineered systems of manufacturing facilities through the development of a taxonomy and associated terminology.Design/methodology/approachThis research performed a comparative analysis of 15 manufacturing facilities located both within the United States (73 percent of cases) and internationally (27 percent of cases). These case studies provided details on how and where flexibility was incorporated into the design of a manufacturing facility. Specific consideration was given to the primary design features that enabled a decoupling of the facility from the manufacturing process. These design features were then clustered to identify main design strategies that enable flexibility.FindingsBy grouping the design features together and creating a common vocabulary, three coherent design approaches for flexible facilities were identified, each having a different potential for responding to short-term and long-term changes. These include general purpose, scalable, and dedicated facilities.Research limitations/implicationsBy delineating three high-level strategies for early flexible facility design, this research synthesizes a conceptual understanding of flexibility with practical and implementable designs. This synthesis provides an incremental advance to a complex challenge for researchers. It also provides decision support to design teams by aiding in project definition, when flexibility is desirable. This research is primarily limited by the number of cases reviewed. With more cases, additional facility design strategies may be identified.Practical implicationsThe findings in this research allow for a basic understanding of how a flexible facility can be designed with only limited or vague information about the product and manufacturing processes contained within. The development of terminology associated with each facility design strategy provides standardization for the discussion and implementation of flexibility early in the design process. In doing so, flexible designs become easier to create and more efficient to implement.Originality/valueThis research provides the first synthesized approach for considering flexible facility design strategies within the manufacturing sector.

Investment incentives for flexible demand options under different market designs

This paper analyzes investment incentives for flexible manufacturing facilities under different market designs. We propose a multi-stage equilibrium model incorporating endogenous determination of generation capacity investment, network expansion and redispatch based on the model introduced by Grimm et al. (2016), including flexibilization of industrial electricity consumption. The model allows to investigate incentives for flexibilization and the impact of flexible industrial electricity consumers on the system. An application to the German electricity market reveals that flexible industrial electricity consumption can be profitable for firms. If the share of flexible electricity consumers is high, price fluctuations are mitigated, which lowers the individual cost savings from demand flexibility. Comparing different market designs, positive impacts of flexible electricity demand on the system are observed in both the system optimum and the market equilibrium. In scenarios with flexible industrial electricity consumption, welfare is considerably higher than in those without. This is due to lower electricity costs of industrial consumers, but more importantly due to less investment in conventional power generation as well as a reduced transmission network expansion. However, a comparison of nodal and uniform pricing underlines the importance of regional price signals with respect to an efficient allocation of flexible industrial demand.

Economical and operational issues for CIGS in the future PV panorama

Due to the low costs of multi-crystalline Si ($0.6/Wp present average, and $0.38/Wp projected by 2018), Cu(InGa)(Se, S)2 (CIGS) thin film is facing a competitive environment as product needs to be aligned in efficiency, reliability and fabrication costs with main stream modules. Moreover, into the final quarter of 2016, the PV industry has been again confronted to an overcapacity panorama, which has demonstrated very harmful for manufacturers and module producers that have not been able to follow the costs reduction learning curve together with increasing in efficiency and product reliability. However, just follow the leader could not be enough, and without innovations leading to new advanced solutions to the stablished market and/or create new ones, the survival of the technology is compromised.In this paper, an approach to the present and a projection of near future competitiveness of CIGS respect to the expected performances in conventional markets is provided. For this efficiency and manufacturing issues related with costs assumptions and bankability are discussed. An example of an industrial line targeting enough flexibility to address present and future emerging markets need is discussed. The main aim is give clues to CIGS manufacturers to develop a competitive product within the future PV panorama and to innovate not only in materials and product, but also in market and business models. At this step, innovation in products, markets, and financial issues seem mandatory for the technology to survive in a very competitive growing global market, and for this flexible manufacturing facilities with reduced costs need to be developed.

Continuous Manufacturing of Recombinant Therapeutic Proteins: Upstream and Downstream Technologies.

Continuous biomanufacturing of recombinant therapeutic proteins offers several potential advantages over conventional batch processing, including reduced cost of goods, more flexible and responsive manufacturing facilities, and improved and consistent product quality. Although continuous approaches to various upstream and downstream unit operations have been considered and studied for decades, in recent years interest and application have accelerated. Researchers have achieved increasingly higher levels of process intensification, and have also begun to integrate different continuous unit operations into larger, holistically continuous processes. This review first discusses approaches for continuous cell culture, with a focus on perfusion-enabling cell separation technologies including gravitational, centrifugal, and acoustic settling, as well as filtration-based techniques. We follow with a review of various continuous downstream unit operations, covering categories such as clarification, chromatography, formulation, and viral inactivation and filtration. The review ends by summarizing case studies of integrated and continuous processing as reported in the literature.

フィジカル・システムと連動した生産設備シミュレーション（設備シミュレーションを構築するためのコンポーネント標準化の提案）

This paper discusses the effectiveness of manufacturing facility simulation linked with physical systems on value chain activities. The activities on manufacturing preparation and implementation processes of manufacturing systems have been improved by manufacturing facility simulation. This method originates from research on the concept of virtual manufacturing environment in the early 1990s. The equipment or facility simulation layer corresponding with the standard hierarchy model of enterprise and control integration is defined. Facility and control model utilized for whole facility lifecycle and its configuration are proposed as a standardization candidate of the reference model. The model consists of digital data of many components including mechanical and control properties like 3D data of mechanism, kinematics, axis, joint, sensor signal and actuator signal. The model should be the standard because the property information of components is only provided by parts suppliers. The facility simulation is linked with both physical controllers and their simulators by standard communication middleware connecting various communication protocols of Real-time Ethernet and fieldbus. After the detail system configuration is described, the applied case studies of improving engineering chain activities in automobile manufacturing are explained. The case studies indicate these systems are efficient to shorten the development period of flexible manufacturing facilities including robots and fixture jigs and to reduce the development cost.

Continuous downstream processing for high value biological products: A Review.

There is growing interest in the possibility of developing truly continuous processes for the large-scale production of high value biological products. Continuous processing has the potential to provide significant reductions in cost and facility size while improving product quality and facilitating the design of flexible multi-product manufacturing facilities. This paper reviews the current state-of-the-art in separations technology suitable for continuous downstream bioprocessing, focusing on unit operations that would be most appropriate for the production of secreted proteins like monoclonal antibodies. This includes cell separation/recycle from the perfusion bioreactor, initial product recovery (capture), product purification (polishing), and formulation. Of particular importance are the available options, and alternatives, for continuous chromatographic separations. Although there are still significant challenges in developing integrated continuous bioprocesses, recent technological advances have provided process developers with a number of attractive options for development of truly continuous bioprocessing operations.

Development of a decentralised control for flexible manufacturing facilities

Flexibility in manufacturing requires new governing concepts and new forms of implementation to increase plant efficiency. This paper presents the results of a prototypical development, which guarantees factory automation using the high performance capabilities of parallel operations (activated by decentralised control), together with the high flexibility of 'expert' governors (with rule–based decision–making architecture). The resulting expert interconnected decentralised control is validated within the SIFIP–simulational environment, realised by the Industrial Robot Design Research Group of the University of Genoa.

Optimal Scheduling Policies for a Production Service System with Two Items

In this paper, we address the capacity allocation rules for a flexible production service system consisting of one flexible manufacturing facility and one service centre. The manufacturing facility produces two items in the first stage and the service centre serves two customers in the second stage. Each order served by the service centre depletes one unit of dedicated item produced by the manufacturing facility. The manager must make production and service capacity allocation decisions. The objective is to find an effective production and service scheduling rule to minimize the expected total cost over an infinite horizon. The service capacity allocation problem is formulated as a Markov decision process and use this formulation to characterize the structure of the optimal service allocation policy. We show that the optimal service scheduling policy is an extension of the well-known optimal service scheduling policy for classical service system. Then the characteristics of the optimal production policy are studied numerically since the analytic characteristics are not available.

Modelling Modular Design Processes for Automated Production Facilities

This paper discusses a concurrent engineering approach for the design of flexible manufacturing facilities where logistics considerations are included in early planning stages. The multidisciplinary approach is based on four modules, automation and robotics, command and control, production planning and layout, and logistics and maintenance planning. The research teams used a variety of operations research techniques to define their preferences for equipment choice and process design. A small case study is used to select design features for a facility for teaching and research, and subsequent transfer to industry. The paper also proposes a multi-criteria approach which allows the four modules to have different and sometimes conflicting objectives. This is exemplified by an application of the analytic hierarchy process method.

The selection allocation problem

The Selection Allocation Problem (SAP) is a single period decision problem which involves selecting profit-maximizing (or cost-minimizing) activities from various distinct groups, and determining the volume of those activities. The activities in each group are selected subject to the availability of that group's resource, which is provided by either pooling or blending raw inputs from several potential sources. Imbedded in the decision process is the additional task of determining how much raw input is to be allocated to each group to form the resource for that group. Instances of this problem can be found in many different areas, such as in tool selection for flexible manufacturing systems, facility location, and funding for social services. Our goal in this paper is to identify and exploit special structures in the (SAP) and use those structures to develop an efficient solution procedure. © 1999 John Wiley & Sons, Inc. Naval Research Logistics 46: 707–725, 1999

The selection allocation problem

The Selection Allocation Problem (SAP) is a single period decision problem which involves selecting profit-maximizing (or cost-minimizing) activities from various distinct groups, and determining the volume of those activities. The activities in each group are selected subject to the availability of that group's resource, which is provided by either pooling or blending raw inputs from several potential sources. Imbedded in the decision process is the additional task of determining how much raw input is to be allocated to each group to form the resource for that group. Instances of this problem can be found in many different areas, such as in tool selection for flexible manufacturing systems, facility location, and funding for social services. Our goal in this paper is to identify and exploit special structures in the (SAP) and use those structures to develop an efficient solution procedure.

A manufacturing model representation of a flexible manufacturing facility

The manufacturing model is an information model that describes the manufacturing capability of a particular enterprise. To achieve general applicability, the model consists of the entities that are relevant and important for any type of manufacturing firm, namely: manufacturing resources (e.g. machines, tools, operators, etc.), manufacturing processes (e.g. machining processes, assembly, etc.) and manufacturing strategies (e.g. how these resources are organized and used). The manufacturing model is a four-level model based on a de facto standard (i.e. factory, shop, cell, station) that represents the functionality of the manufacturing facility of any firm. The manufacturing model concept presented in this paper represents the manufacturing capability of a high-performance flexible manufacturing facility.

A multi-level modelling system for the design of flexible machining installations

Modern flexible manufacturing facilities can be highly complex, consisting of the latest developments in machine tool technology, automated material handling systems and sophisticated cell controllers. The design and management of such systems requires a large number of decisions and choices with regard to production mix, assignment of fixtures and cutting tools. A large number of commercial computer modelling packages are now available in the market place. Although these allow valuable assistance in the analysis of a manufacturing facility, they usually take significant amounts of time to build models and require a large amount of training, and can be constraining in their application. This paper establishes a research prototype for a multi-level approach for the realization of a three-phase design and modelling system for flexible machining facilities. It portrays the view of an integrated fully data-driven solution underpinned by a machining cell database, and outlines three major areas of work within the structure, i.e. the 'Cell Configurator', 'Evaluator' and 'Emulator'. The approach is demonstrated and supported throughout the paper by an industrial case study of a modern three-machine flexible machining cell, illustrating the use of the underlying methodology behind the approach and typical inputs/outputs at each phase. The final part of the paper provides a discussion of the approach adopted based on user comments and in relation to commercial simulation tools available.

Valuing flexible manufacturing facilities as options

Models for valuing an option to exchange one commodity for another, or any combination of n input commodities for some combination of m outputs, are applied to the capital budgeting problem-making it possible to draw sound conclusions about the valuation effects of flexibility and innovativeness. New algorithms enable practical application of the model to complex flexible manufacturing facilities. Careful attention to estimating the matrix of correlations among the prices of potential inputs and outputs involves explicit integration of financial analysis and strategic analysis-especially the influence of substitutes and the anticipated reactions of competitors, suppliers, and potential new entrants.

Selection of routes in a flexible manufacturing facility

Routeing flexibility is defined as the ability to manufacture a product via several alternate routes in the same facility. A route is defined as the set of work centers or machines through which a product is processed, and the processing times at these work centers. Routeing flexibility permits the facility to adjust to changes in the production ratio. Typically, with every change in the production ratio, the FMS scheduler will assign routes to each product, so as to achieve a close to perfect load balance between work centers while minimizing the interference or setups between processing routes. The assigned routes will belong to the set of routes that have been implemented, and hence are available for scheduling. A route is described as implemented when the instructions, skills, tools, handling needs, and other auxiliaries associated with it have been positioned in the facility. The ability to change routes and optimize performance is therefore dependent on the routes which have been implemented. In this paper we assume that several good and feasible routes are generated by the process planner for each product. Since it is economically possible to implement only a few routes per product, the route selection problem is described as identifying the set of routes which should be implemented so as to optimize routeing flexibility related costs. The problem is formulated as a mixed integer program and rules for deriving tight initial solutions are proposed. Tests with sample problems were conducted, and model sensitivity to the scenario change factor and present worth factor were studied.

Clustering algorithms to optimize the tool handling system management in an FMS

Tool management is recognized as a critical issue in flexible manufacturing facilities management. This article addresses the issue of tool management in a flexible system installed in an avionics components factory. The system is composed of two machining centers equipped with local tool magazines of limited capacity. A tool handling system is in charge of tool movements between the tool room and the two machines. Each machine is able to perform any operation, provided that it is equipped with the suitable tool. In this kind of installation, tool allocation must be determined, and tool movements must be synchronized in order to minimize operating costs, or, equivalently, maximize the productivity of the system. We propose an approach to production planning based on a clustering algorithm, which takes into account the tool requirements of each part program in the production batch. We also propose two different heuristics for the scheduling problem. A case study was conducted on the facility mentioned above. Two conflicting objectives can be identified for this kind of production system: the reduction of tools to be shared among machines and the reduction of workload unbalance. The tests and comparison made demonstrate how the proposed procedure leads to superior results in terms of both objectives.

Design of a tool management system in a flexible cell

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

Stability of Flexible Manufacturing Systems

We consider a flexible manufacturing facility that can be operated in any of m different modes. While running in mode k certain intermediate products are consumed and other intermediate or finished products are created. There may be variability in the manufacturing process, as well as random arrivals of raw materials and orders for finished products. We establish conditions that ensure demands can be satisfied while maintaining bounded levels of inventories. These results that may be viewed as generalizing to the flexible manufacturing context the notion of stability for a queueing system.

An intelligent user interface in a knowledge-based modelling system for the design of flexible manufacturing facilities

Abstract There are currently a large number of available modelling tools each offering an alternative approach to building a model and representing the working of the model once built. Most of the existing methods, however, fall well short on providing effective user-system interaction capabilities with respect to the requirements of system modelling in flexible manufacturing. The purpose of this paper is to introduce to the reader an intelligent user interface in a knowledge-based modelling system for flexible manufacturing facilities. The requirements for the user interface of a manufacturing system modelling tool are discussed. This is followed by a description of the overall structure and each of the components of the researched user interface.