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Proceedings of the 24th International Conference on Flexible Automation & Intelligent Manufacturing; FAIM 2014
No full textPaper presented at the Proceedings of the 24th International Conference on Flexible Automation & Intelligent Manufacturing, held May 20-23, 2014 in San Antonio, Texas, and organized by the Center for Advanced Manufacturing and Lean Systems, University of Texas at San Antonio; Includes bibliographical references; The first step in the Theory of Constraints (TOC) methodology is to identify the constraint. Several methods have been recommended in literature, such as looking for a backup of inventory (i.e., the operation that the inventory is waiting for is the constraint), or using linear programming or other analytical models. Yet, these methods may not be useful in a matured lean environment, which may have moving assembly lines where constraints are not obvious. This paper proposes two new methods for this purpose. The first method, Flow Constraint Analysis, takes a holistic view and evaluates whether the customer’s demand is being satisfied. This evaluation is made by comparing the takt times and the cycle times of resources in the manufacturing system in order to identify the constraint(s). The second method, Effective Utilization Analysis, can be employed to pinpoint the location of the system constraint to a specific process or station. The actual production throughput is compared against the ideal capacity of the system to locate the bottleneck. This method is based on the relationship between WIP, bottleneck rate and lead time for a constant work in process (CONWIP) system. A case study of both methods applied to an actual production facility is presente
Proceedings of the 24th International Conference on Flexible Automation & Intelligent Manufacturing; FAIM 2014
No full textPaper presented at the Proceedings of the 24th International Conference on Flexible Automation & Intelligent Manufacturing, held May 20-23, 2014 in San Antonio, Texas, and organized by the Center for Advanced Manufacturing and Lean Systems, University of Texas at San Antonio; Includes bibliographical references; Today's business conditions are characterized by increased competition. Therefore enterprises have to cope with shorter product life cycles, higher product complexity and more product variants. The reaction of many enterprises is to launch new products in shorter intervals. This confronts companies with the challenge to pass through the product development process faster. The product development processes need to be parallelized and waste within the processes needs to be identified. In the past, methods of Lean Production Systems have been successfully used to identify waste in production and product development processes. Lean offers an established approach to eliminate waste and increase customer value in all processes. Especially the value stream mapping method is used to identify waste in processes and to concentrate on value creation. To improve the entire product development process from development to start of production, this process has to be mapped and analyzed. Therefore, this article analyzes different value stream mapping methods regarding the specific requirements of the product development process. In the following, an approach is presented which has been tested in an enterprise in order to improve the product development proces
Proceedings of the 24th International Conference on Flexible Automation & Intelligent Manufacturing; FAIM 2014
No full textPaper presented at the Proceedings of the 24th International Conference on Flexible Automation & Intelligent Manufacturing, held May 20-23, 2014 in San Antonio, Texas, and organized by the Center for Advanced Manufacturing and Lean Systems, University of Texas at San Antonio; Includes bibliographical references; Many of the applications in the 3D printing market have been for manufacturing prototypes in an inexpensive and relatively fast manner. Today, 3D printers make this possible by no longer having to use third party manufacturers. For all of the purposes that 3D printing is used, many of them, such as 3D geographic maps, visual art, model support structures, dioramas, prototypes, do not require a high precession. Furthermore, for such applications, there is no need for permanent prints. Due to the advancements in technology, and its residual pollution from waste, there is a need for a ‘greener’ method to 3-D printing. To meet this demand, we propose MIRV (Mechanically Interchangeable and Reusable Voxels), for voxel-based printing, a new method for 3-D printing. MIRV uses pre-built volumetric elements to build 3-D objects, by employing specially designed reusable and interchangeable building elements in voxel-based printing. When there is no longer need for the printed object, the object can be disassembled and the parts reused. This eliminates any wasted material. Meanwhile, all building elements of each layer are displaced in one simultaneous motion. Thus, the overall time to build a print can be significantly reduced compared to other 3D printing technologie
Proceedings of the 24th International Conference on Flexible Automation & Intelligent Manufacturing; FAIM 2014
No full textPaper presented at the Proceedings of the 24th International Conference on Flexible Automation & Intelligent Manufacturing, held May 20-23, 2014 in San Antonio, Texas, and organized by the Center for Advanced Manufacturing and Lean Systems, University of Texas at San Antonio; Includes bibliographical references; The efficient and effective engineering of industrial plants has a high impact on the success of numerous companies. Core of engineering activities is to accurately cover the requirements of the customer and design and build a perfectly fitting solution. Due to the one-time character of these projects, time and money can be saved by a reuse of knowledge from former projects as well as a strong methodology to execute these complex projects. The need for an efficient exchange of knowledge and further development of engineering methods (e.g. resource planning, training concepts, cross-country collaboration) has been recognized by many companies on a top level. At the same time there is currently no consistent approach, how to involve the experience of a broad engineering community in the development and implementation of efficient methods. This work describes an approach which closes the gap between a grown “community of practice” and a top-down initiative for the development of engineering methods and structured knowledge exchange. It ensures the deep involvement of experienced engineers from a vivid community for exchange and feedback. Three formerly described design principles (stakeholders, infrastructure, content and activities) of a community-based initiative have been applied to in a multi-sector engineering compan
Proceedings of the 24th International Conference on Flexible Automation & Intelligent Manufacturing; FAIM 2014
No full textPaper presented at the Proceedings of the 24th International Conference on Flexible Automation & Intelligent Manufacturing, held May 20-23, 2014 in San Antonio, Texas, and organized by the Center for Advanced Manufacturing and Lean Systems, University of Texas at San Antonio; Includes bibliographical references; Most of the past studies regarding machining optimization were based on machining science and economic considerations without the environmental dimension. Machining with higher cutting speed is usually desirable considering productivity, but requires high power load peak. In Taiwan, electricity price goes up sharply if the instantaneous power demand is over the contract capacity. Production scheduling problems have been widely studied for decades. However, majority of these studies consider jobs are known and processing times are certain. Besides, traditional sequencing and scheduling models deals with the economic objectives. There is still a severe lack of environmental considerations for production scheduling problems. In this study, we deal with a production scheduling problem for a manufacturing system with a bounded power demand peak. It is necessary to simultaneously determine proper cutting conditions for jobs and assign them to machines for processing without exceeding the electricity load limit at any point of time. A two-stage heuristic approach is proposed to solve the parallel machine scheduling problem with the goal of minimizing makespan. An illustrated instance with 3 machines and 20 jobs, each job in details with four possible cutting parameter settings for selection, is studied and employed to investigate the performance of the proposed heuristi
Scientific Report
No full textThis collection includes digitized publications of the Texas Biomedical Research Institute between 1953 and the present
Proceedings of the 24th International Conference on Flexible Automation & Intelligent Manufacturing; FAIM 2014
No full textPaper presented at the Proceedings of the 24th International Conference on Flexible Automation & Intelligent Manufacturing, held May 20-23, 2014 in San Antonio, Texas, and organized by the Center for Advanced Manufacturing and Lean Systems, University of Texas at San Antonio; Includes bibliographical references; This paper focuses on a simple perishable product supply chain with a vendor and multiple retailers. These retailers, densely dispersed in a distribution zone, are sensitive to price, delivery time and product quality. With the aim of optimizing vendor's average expected profit during a shipment consolidation cycle, an analytical model is proposed for this problem. The upper unbound expressions of optimal time policy and fresh-keeping cost are given based on a certain range of time parameter. Then our theoretical findings are verified by using a numerical case. Some useful managerial insights are obtained based on analyzing the sensitivity of this model on major parameter
Proceedings of the 24th International Conference on Flexible Automation & Intelligent Manufacturing; FAIM 2014
No full textPaper presented at the Proceedings of the 24th International Conference on Flexible Automation & Intelligent Manufacturing, held May 20-23, 2014 in San Antonio, Texas, and organized by the Center for Advanced Manufacturing and Lean Systems, University of Texas at San Antonio; Includes bibliographical references; In robotic applications, the communication protocol is one of the main features that dictate scalability and network topology. The communication architecture must consider heterogeneity (i.e. network, hardware, operational system and programming language) and provide programming abstraction to simplify its development. There are several middlewares and frameworks that can be applied in robotic applications, differing considerably in complexity, programming languages and approach. In this context, this paper presents a communication architecture that fulfils such requirements and ensures information exchange through the network. It was evolved from a previous study, providing more flexibility and easily to adapt to other applications. An interface definition language (IDL) was conceived that enables users to define and deploy services, and also adjustable constraints (service request timeout, message size, maximum number of connected nodes) that restrict provided functionalities. The middleware is based on a multi-threaded service-oriented hybrid peer-to-peer architecture that uses concepts of object-oriented programming in a layered structure to provide flexibility for the communication implementation, minimizing code changes when ported to other robotic systems. Tests of availability and network response time were performed to evaluate its time constraints. The middleware applicability was proven when implemented in an AGV distributed system, designed to operate an intelligent warehous
Proceedings of the 24th International Conference on Flexible Automation & Intelligent Manufacturing; FAIM 2014
No full textPaper presented at the Proceedings of the 24th International Conference on Flexible Automation & Intelligent Manufacturing, held May 20-23, 2014 in San Antonio, Texas, and organized by the Center for Advanced Manufacturing and Lean Systems, University of Texas at San Antonio; Includes bibliographical references; The importance of small and medium sized companies as a leader for globalization has been recognized through various sources. One class of these companies is called the Hidden Champions. A Hidden Champion company
thrives to operate as a global leader in a niche market. The competence factors of the hidden champion companies have been identified in a previous research conducted by Hermann Simon. The competence factors do not include or define the role of production or the production strategy. The purpose of this paper is to study the impact of the decision made in production strategy to correspond to the identified competence factors. This study includes a definition of the hi
Proceedings of the 24th International Conference on Flexible Automation & Intelligent Manufacturing; FAIM 2014
No full textPaper presented at the Proceedings of the 24th International Conference on Flexible Automation & Intelligent Manufacturing, held May 20-23, 2014 in San Antonio, Texas, and organized by the Center for Advanced Manufacturing and Lean Systems, University of Texas at San Antonio; Includes bibliographical references; There are boundless upcoming factors that influence future of material waste in production. This broad range of
factors needs to be scanned, categorized and analyzed in a structured way. This paper by a foresight study, aims to give an insight and increase awareness about external macro-level future trends concerning raw material consumption and waste generation in production. A limited pilot study indicated that technological forecasting and some reaction upon obvious trends are being taken, although in an ad hoc manner and without structured tools. However, political influences, economic visions and social-cultural shifts were seldom or never discussed. External macro trends and tendencies were examined through PEST analysis to identify potentials and opportunities influencing strategic decisions and innovation initiatives. It is vital to understand the whole picture of possible changes and not only considering the technological trends, but also other relevant development areas that might affect production in different ways