Georges Abdul-Nour

Physically reconfigurable virtual cells: a dynamic model for a highly dynamic environment

Abstract This paper presents a scheduling framework for sustaining a manufacturing environment that is said to be very dynamic and turbulent. The framework proposes five modules: part family formulation, family sequencing, cellular configuration, jobs scheduling and system monitoring. The modules will configure the workstations in virtual, dynamic or hybrid cells. Decision criteria are exclusively economic and aim at minimizing the cost for transfering unit loads and the cost for relocating processors.

Dynamic cellular manufacturing system (DCMS)

Abstract This paper presents a dynamic cellular manufacturing system (DCMS) that sustains the turbulent environment of small make-to-order manufacturers and subcontractors. The DCMS exploits the workstation moveableness to reconfigure the cells. The system is composed of 4 modules; loading and routing module, dynamic cell configurator, scheduling module and system monitoring. The core of the DCMS is the cost based algorythm for dynamic cell configuration, its decision criteria are exclusively economic and aim at minimizing the overall cost for transfering unit loads and relocating workstations.

A reliability based maintenance policy: a case study

Reliability centered maintenance (RCM) incorporates sound guidance for managers who wish to attain high standards of maintenance at their operating plants. Since the amount and type of maintenance which is applied depend strongly on the machine or components age (DFR, CFR or IFR), on its replacement cost as well as on the cost and safety consequences of system failure, a careful analysis of the system components based on their reliability data should be done in order to optimize the maintenance program. This paper describes the methodology which was used at an aluminum plant in order to select critical machines and to develop an optimal maintenance policy based on reliability data of each machine, safety consequences of system failure, lead time and repair time, and components criticality.

Simulation-based performance comparison between dynamic cells, classical cells and job shops: a case study

This paper presents the results of a simulation-based performance comparison between dynamic cellular (DC) manufacturing systems and two other well-known systems, namely classical cells (CC) and job shop systems (JS). The performance comparison is made at different levels of turbulence. The experiment contains 13 independent variables, most of them related to demand turbulence, and 17 dependant variables related to performance measure. A stochastic simulation model developed on Microsoft Visual FoxPro 5.0 was used in combination with LINDO (a linear/integer programming software) to obtain the initial results. In view of the large number of variables and the time required to run each experiment, a Taguchi plan was used to optimize the model. The results obtained from the analysis of variance indicate that dynamic cellular manufacturing systems are generally more efficient than classical cellular systems or job shop systems, especially with respect to the average and maximum throughput time, mean and maximum work-in-process, mean and maximum tardiness, and the total marginal cost for a given horizon.

Mixed production, flexibility and SME

In this study, a step by step management approach is developed in order to help SME (Small Manufacturing Enterprise) to reach basic, system, and aggregate flexibility and agility, despite their lack of resources. This research is justified by the fact that some large factories are lowering their fixed cost by moving processing machine towards specialized SME, and creating intelligent network of factories based on innovation, agility and JIT philosophy.

Adaptation of JIT phylosophy and Kanban technique to a small-sized manufacturing firm; a project management approach

Abstract In this study, a project management approach is used, in order to implement some elements of the Just-In-time philosophy to a small-sized manufacturing firm. The objective of this applied research was to overcome some of the problems that most of small firms are facing when implementing JIT, such problems are: lack of materials and human resources, high employees turnover, lack of influence over suppliers, etc. In order to overcome those obstacles, a project management approach was used. As a result of this project, productivity and quality went up, and lead time went down from six to less then two months.

SME and quality performance in networking environment

Abstract In this study, a step-by-step management approach is developed in order to help small manufacturing enterprise to reach better quality level in term of quality management, quality assurance, quality control and continuous improvement process, despite their area of operation and level of expertise in quality matter. This research is justified by the fact that some large factories and other foreign business are continuously raising their quality requirement at all level. Therefore, one way to acquire expertise is to exchange knowledge and know-how in networking environment.

Studying the performance of a dynamic cellular manufacturing system

This paper aims at studying and comparing the performance of a Dynamic Cellular Manufacturing System (DCMS) with a Classical Cellular Manufacturing System (CCMS). A case study has been realized through the use of a bench test and several measures of performance were collected. The study indicates that the DCM concept permit gains both in terms of performance and flexibility by capitalizing on the advances in computer science and information technology. Even though the dynamic cellular concept is in its early infancy, research being conducted tends to indicate that this new organization paradigm may be a serious rival to the classical cellular organization.

Probabilistic safety assessment and reliability based maintenance policies: application to the emergency diesel generators of a nuclear power plant

This study is performed on the four 2.5 MWe emergency diesel generator (EDG) sets of Hydro-Quebec Gentilly-2 Nuclear Power Station. EDGs are safety related systems for the case of the loss of off-site power. This study establishes the basis of an enhanced preventative maintenance and periodic testing program with the objective of improving the long-term reliability and availability of the EDG. It is also the first step to a PSA program based on the real historical data of the system.

Manufacturing flexibility: SMT factors study

Electronics manufacturers are facing evolutionary and highly dynamic environment. Flexibility is becoming a must in their manufacturing processes especially those using surface mount technology (SMT). This study consists of assessing and predicting the effects of different strategies of products family formation based on different group technology policies (GSU and SDS); other operational variables are the flexibility and the performance of a SMT assembly line and reduction of setup time. Simulation and experimental design are used in order to predict the line performance.