Copyright (c) 2009 All rights reserved. http://works.bepress.com/djassemi Recent documents in Manocher Djassemi en-us Tue, 22 Sep 2009 12:53:08 PDT 3600 http://works.bepress.com/djassemi/19 http://works.bepress.com/djassemi/19 Fri, 31 Jul 2009 16:16:45 PDT An important part of financial planning in product development is considering whether the capital expenditures meet volume and cost goals. A good business plan should provide investors with the implications of process selection on the company's bottom line. It is estimated that there are least 1000 manufacturing processes and sub-processes. Considering the number of process choices and quantity of cost data, an economic analysis for process selection may pose a challenge for decision makers. This paper provides an insight to Ashby's cost modeling method for generating an estimate of unit product cost. The cost model provides a broad indicator for competing processes for shaping a product at the early stage of product development. This model takes into account the cost of resources associated with manufacturing a component. Using the Cambridge Engineering Selector software the impact of various cost factors on process selection is investigated. Manocher Djassemi Conference Proceedings http://works.bepress.com/djassemi/18 http://works.bepress.com/djassemi/18 Mon, 20 Jul 2009 11:26:10 PDT In this paper, two types of similarity coefficients are compared: (1) the Jaccard's coefficient and (2) the production volume based coefficient. Each is used to form a cellular manufacturing system whose performance will be used as a measure of effectiveness of the similarity coefficient. The sum of intercellular and intracellular material handling costs is used as a criterion for performance evaluation. Hamid Seifoddini Articles http://works.bepress.com/djassemi/17 http://works.bepress.com/djassemi/17 Mon, 20 Jul 2009 11:26:09 PDT Group efficiency measures have been developed to evaluate machine-component charts for the formation of cellular manufacturing systems. In this paper the existing grouping efficiency measures will be evaluated by determining the relationship between the values of a grouping efficiency measure and the performance of the corresponding cellular manufacturing system. Hamid Seifoddini Articles http://works.bepress.com/djassemi/16 http://works.bepress.com/djassemi/16 Mon, 20 Jul 2009 11:26:08 PDT Many studies and reports support the significant impact of the application of group technology on various aspects of product design and manufacturing. The fact that group technology is the common solution to similar problems is the main source of such impact. In this paper, one of the less frequently utilized features of CNC technology known as parametric part programming is used to implement the common solution feature of group technology in processing a set of similar parts. Using three part families, the advantages of blending the concept of group technology and parametric programming for CNC machining operations are illustrated. The efficiency improvement due to the use of parametric programming in terms of number of setups and size of program is discussed. Manocher Djassemi Articles http://works.bepress.com/djassemi/15 http://works.bepress.com/djassemi/15 Mon, 20 Jul 2009 11:26:08 PDT This paper compares the performance of Jaccard's similarity coefficient with the production data-based similarity coefficient. A number of machine-component charts taken from the literature or randomly generated are used to form machine-component groups. Then, the sum of intercellular and intracellular material handling costs for each machine-component group is calculated and used as a basis for performance evaluation of the two similarity coefficients. Hamid Seifoddini Articles http://works.bepress.com/djassemi/14 http://works.bepress.com/djassemi/14 Mon, 20 Jul 2009 11:26:07 PDT A major contributing factor to the under utilization of machines in cellular manufacturing is the development of long queues in front of some machines in machine cells. This paper presents a procedure which identifies such machines and redistributes their loads to alternative machines whenever feasible. Hamid Seifoddini Articles http://works.bepress.com/djassemi/13 http://works.bepress.com/djassemi/13 Wed, 01 Jul 2009 15:05:07 PDT Purpose - In spite of having a number of general-purpose algorithms for solving plant layout problems, facility planners may still face a challenging task to adjust these algorithms to handle special, but not uncommon, layout problems. The purpose of this study is to propose a new method for addressing the impact of overhead space utilization on a plant layout solution. Design/methodology/approach - A new method for adjusting material flow under a mixed floor and overhead material handling condition is incorporated in an existing plant layout procedure. A case study involving the layout improvement in a lawn mower engine assembly facility is presented to illustrate the effectiveness of the proposed method. Findings - The analysis of solutions for the case study shows that the layout generated by the proposed modified material flow approach is a more economical solution. The case also shows, when it is important to optimize the use of space, the overhead space should be considered as part of any methodology for designing a good layout. Research limitations/implications - The proposed modified material flow approach can be applied to any facility where the use of overhead space for material handling is justifiable by limited floor space and/or by high cost of land. The proposed method can be applied to small to medium size problems with minimal computational effort. However, as the size of facility grows, the manual calculation becomes more time consuming and potentially erratic. Originality/value - This paper should be useful to both researchers and practitioners who deal with overhead space utilization in designing facility layouts. Manocher Djassemi Articles http://works.bepress.com/djassemi/12 http://works.bepress.com/djassemi/12 Wed, 01 Jul 2009 15:05:06 PDT The performance of cellular manufacturing (CM) systems in a variable demand and flexible workforce environment has been examined using simulation modelling. Discrepancies between academicians and practitioners' findings with respect to flexibility and uneven machine utilization in CM systems are discussed. The views of two parties were incorporated in simulation models to rectify the existing discrepancies. While the results of this study confirm the previous findings of academicians regarding the deterioration of the performance of CM in a variable product mix situation, it appears that those results may be significantly influenced by considering a flexible workforce. The simulation results show that the practice of using flexible crossed-trained operators can improve the flexibility of CM in dealing with an unstable demand and can reduce load imbalance inherent in machine dedication in manufacturing cells. Manocher Djassemi Articles http://works.bepress.com/djassemi/11 http://works.bepress.com/djassemi/11 Wed, 01 Jul 2009 15:05:06 PDT In this paper, performance measures such as mean flow time and work-in-process inventories will be used to determine the changes in the performance of a cellular manufacturing system due to product mix variations. Hamid Seifoddini Articles http://works.bepress.com/djassemi/10 http://works.bepress.com/djassemi/10 Wed, 01 Jul 2009 15:05:05 PDT Quality index (QI) has been proposed as a screening mechanism for machine-part matrices in the development of cellular manufacturing systems. In this paper the effect of reliability consideration on the application of QI and the relative sensitivity of job shop and cellular manufacturing systems to reliability changes are evaluated by simulation modeling. Performance measures such as mean flow time and work-in-process inventories are used in the comparative study of job shop and cellular manufacturing. Hamid Seifoddini Articles