Applied Mechanics and Materials Vols. 809-810

Abstract: The searching state space in scheduling of real manufacturing systems with discrete and multi-assortment production is discussed in this paper. The production load is represented by a directed and/or graph called “the aggregated graph of operations planning of the set of orders”. It determines the order of operations, according to which they will be inserted into a schedule. This order must always comply with all assumed precedence and resource constraints and also with given scheduling strategy of a production order. In the elaborated representation the complex products structures and alternative routes of their realization are also considered. The most important issues related to searching this space are discussed in this paper. These include: a general method for searching the graph, sequencing of parallel processes and operations using schedule generation schemes and selection of routes variants.

Abstract: It is well known fact that materials play an important role in engineering design. Nowadays over a hundred thousand available materials can be distinguished with constant tendency for increasing the novel designed materials. Therefore material selection process becomes a complex and time consuming task. Selection of the most suitable material for a given application can be regarded as a multi-criteria decision making (MCDM) problem with conflicting and diverse objectives. New MCDM methods have been developed, and existing methods improved, showing that research in the decision-making is important and still valuable. This paper describes the use of recently developed MCDM methods, i.e. Complex Proportional Assessment (COPRAS) and Weighted Aggregated Sum Product Assessment (WASPAS) for selecting the most suitable hard coating material.

Abstract: This paper presents the modeling and analysis of processing flow in a flexible manufacturing system. We considered the case of a flexible manufacturing system consists of three machining centers MC1, MC2, MC3 and two material handling system which assure parts loading and discharge, respectively. The parts incorporate an Arduino system with XBee wireless module. These embedded systems connected through a network wireless can allow easy identification of parts, easy identification of their position, of performed operations, ensuring optimal guiding pallets. In order to be able to model all the requirements imposed were used synchronized Petri nets with inhibiting arcs and with threshold test. Developed model aims to optimize parts flow, under the conditions in which MC1 and MC3 have a buffer for 3 parts and MC2 have a buffer for 4 parts, respectively. By implementing a wireless ZigBee network for the control of parts movement it provides a modern solution by which central control system will know the position of every intelligent parts and will be able change the flow of processing according to unpredictable circumstances. FMS modeling is useful both in the design to implementation of the program which controls material movements and machine flow, as well as part of exploitation, providing a clear view of FMS functioning. By that model verified through simulation it was able to optimize the flow of parts, so as that there are no blockage in the flow of manufacturing. The study allows software implementation of control systems for the FMS.

Abstract: The purpose of this paper is to present a method to quantify the costs of potential losses from production processes for new products to prioritize improvement projects based on the target cost and provide data and information for feasibility studies of continuous improvement projects. The specificity of the manufacturing cost policy deployment for new products is to identify the percentage of cost of future production phases which does not add value from a customer perspective, dynamically throughout the product life cycle. The percentage of non-value added cost is based on loss of each manufacturing process and is determined scientifically based on data and facts. Using the proposed method helps manufacturing companies in the acceptance of certain orders which at first glance are unprofitable. Moreover, the proposed method will help develop scenarios for continuous cost reduction after starting production through continuous improvement of productivity and quality required. The empirical results are based on the study during a year and a half in the automotive company, using action research methodology.

Abstract: The construction domain is an important part of everybody's life consisting of one of the major needs in the Maslow's pyramid: safety. The now-a-days complex, spectacular designed constructions imply new technologies with high efficiency and precise equipment.The paper analyses the optimum solution for the desired product by using the PLM (Product Lifecycle Management) approach, starting by using previous primary and secondary information and pursuing with the solution determination. The conceptual solutions are obtained through creative methods from the specifications-the functions-of the improved product.Hence, having the proper solution that responds to the client's needs we can make the next step in designing the model of the improved formwork equipment.

Abstract: The research approach presented in the paper targets the integration of some advanced engineering principles, methods and instruments for enhancing the effectiveness and efficiency of Product Design activities. In order to reduce the product development resources consumption, to improve the product functionality, reliability and flexibility and to reduce the product lifecycle environmental impact, all of these being considered as instruments for improving Product Sustainability, some conceptual models for integrating advanced Product Design theories and principles such as Holistic Design and Axiomatic Design, together with the use of some advanced CAD/CAE tools are discussed in the paper. As case study, the paper submits to discussion the problem of enhancing the design activities for the development of a technical solution of a device adaptable on an electrical discharge machine-tool and being able to generate cycloid profiles based on a double-planetary mechanism driving. The research approach on integrating the principles of axiomatic design within activities of the design model structuring, the decomposition rules have been mainly targeted to be applied. The presented case study refers also to the performance of using advanced capabilities of Solid Edge as CAD solution which provides dynamic generation of the product model structure and to those of its embedded module entitled Engineering Reference, as valuable CAE instrument. Some adequate conclusions are finally presented and some directions of further research development are identified, such as integrating also an economic efficiency analysis and a Life Cycle Impact Assessment approach as Concurrent Engineering activities, to enhance the new product development sustainability.

Abstract: Overall effectiveness (OE) for CNC machine tools is a metric sistem for assessing the production obtained performance. To optimize OE is necessary to determine the performance indicators [1,2], identifying and correcting the non-values ​​[3,4,5]. In this paper we propose new methods for CNC machine tools OE improvement, through IFA (Information Focus Action) analysis of production losses, during milling machine Wissner Wi3020 type. Comparison of real OE diagram with the theoretical one, provides information about the real losses associated with sub-processes. Also, root-cause analysis of performance losses, leading to the generation of new ways to improve the CNC machine tools OE.

Abstract: In this paper are proposed two new approaches to maintenance strategies for Computer Numerical Control (CNC) machine tools. The analysis is done for different families of CNC machine tools from S.C. Elmet Bacau, a company specialized in aviation. In maintenance actions applied to CNC machine tools is very important to know the evolution of defects and critical state of electrical and mechanical components. The results of this analysis concludes that maintenance actions can be judged by the developing time period diagram, between failure appearance and interruptions in operation. It is also analyzed the financial impact, revealed from known maintenance strategies adopted on CNC machine tools, resulting in a positive approach of condition based maintenance.

Abstract: This paper presents case study of data acquisition in non-automated discrete production system. The issue of acquisition of data from the production system in order to support company management is essential for the integration of business and manufacturing areas of the company. Properly organized data acquisition system, consisting of hardware, software and organizational solutions, should provide access to real-time data on production tasks, flow of materials and work in progress, usage and effectiveness of workers and equipment, and the quality of production. Availability of data depends on type of production system, more precisely on the level of automation of technological processes. The Manufacturing Information Acquisition System (MIAS) methodology has been used in order to support design of the data acquisition system for the company producing large tanks, in which there is no automated equipment and most of production operations are realised manually. The algorithm of acquiring data from workers, organisational solutions and data processing in developed “Mistrz” IT system has been described, as well as problems with MIAS encountered during system operation in early stages of introduction.

Abstract: We present a novel approach for automatically create industrial products, namely powertrains consisting of engine, transmission and power shaft. We apply a genetic algorithm for exploring the solution space, consisting of 3000 variants, using various criteria, such as power, efficiency and rotation speed. We compare our results with the ones obtained by a human expert in terms of number of feasible solutions, respectively in terms of best and average price. We prove that the proposed approach is generally better than a human expert in exploring the solution space.