Zubair M. Mohamed

An integrated location, production, distribution and investment model for a multinational corporation

Abstract We present a mixed integer linear formulation that extends published models on multinational corporation facility location decisions by including exogenous variables such as exchange rates and tariff rates and incorporating production, distribution, and investment decisions. The model provides insights on production levels; facility configurations, distribution strategies and levels of investment needed at these facilities and explores factors that influence the facilitys configuration decisions. Several scenarios are considered based on various facility configurations and levels of exchange and tariff rates. The results obtained from these show that the models performance and results are in complete agreement with accepted economic theories.

An integrated production-distribution model for a multi-national company operating under varying exchange rates

Research modeling the production planning and logistics decisions for multi-national companies (MNCs) operating under varying inflation and exchange rates is scanty. Decisions regarding the products to be made in different facilities, and the markets which these facilities would serve are critical to the MNCs success. Also, decisions regarding when to open, retain, and close facilities are equally important. These decisions are sensitive to both inflation and exchange rates. Accordingly, we incorporate these parameters in the development of an integrated production planning and distribution model for an MNC. We elicit the performance of the model through examples. Our results indicate profit reduces by as much as 45.77% depending on the exchange rates, initial capacities, and restrictions imposed on the more profitable facility.

The measurement and use of operational flexibility in the loading of Flexible Manufacturing Systems

Abstract Flexibility has been recognized as a key aspect of a firms response to competitive markets. However, no accepted measures of flexibility exist that would allow firms to evaluate FMS planning policies. In this paper, three measures of operational flexibility are derived to represent the ability of an FMS to respond to external and internal disturbances given a production plan. These flexibility measures are then used to evaluate tool loading and part routing decisions. A minimum-cost tool loading and part routing policy is derived, modeled, and statistically tested against a maximum-production-rate policy. The minimum-cost policy resulted in inventory levels being lowered by as much as 43% while routing flexibility increases by as much as 11% without statistically affecting capacity flexibility or the planned makespan.

The impact of machine flexibility on the performance of flexible manufacturing systems

The performance of flexible manufacturing systems, (FMS) has been one of the major topics that has attracted the attention of production and operations management (POM) researchers for the last two decades. In this paper we study the relationship between the degree of machine flexibility and the level of system performance. A machine loading and routing model is developed and used to investigate the effect of changing machine flexibility on the performance measures of an FMS. The measures used in this paper include makespan, routing flexibility, capacity flexibility, and inventory effects. The results indicate that changes in the machine flexibility affect some measures more than others. The results also show that, for a decrease of 24 per cent in the degree of machine flexibility, makespan increases by 17 per cent, routing flexibility decreases by as much as 13 per cent, and capacity flexibility decreases by as much as 38 per cent, and the inventory decreases by as much as 26 per cent. Furthermore, as the workload on the FMS increases, the differences in the performance between two FMSs (with different degrees of machine flexibility) increase.

Organisational factors for successful implementation of ERP systems

Given the substantial investments of time, money and other resources, as well as the technical and organisational risks involved, it is important to understand what is needed to ensure a successful ERP implementation. In this study, we identified the critical success factors for ERP implementations from the relevant literature, categorised them into a sound theoretical framework and linked them to ERP success outcomes. We also provided empirical evidence from two companies that have recently implemented ERP systems. We utilised the theories of business process change, process change management and the literature on information systems success.

A simulation analysis of factors influencing the flow time and through‐put performance of functional and cellular layouts

Contrasts functional layouts and cellular layouts with regard to the effects of set‐up time reduction and lot size on flow time and through‐put. The structural environment for the functional analysis is an efficient functional system with a staged sequence of four machine centers with unidirectional flow and no backtracking. The structural environment for the cellular analysis is a partitioned cell consisting of one machine from each of the four machine types with unidirectional flow and no backtracking. Simulation models produce robust results for eight lot size levels and one (functional model) and seven (cellular model) set‐up time reduction levels. The results contrast the effectiveness of the two manufacturing approaches under differing input conditions. Shows that the choice between the functional structure and the cellular structure significantly affects through‐put at lot sizes up to 55, while for lot sizes of 60 and above there is no significant effect. The study also confirms previous results regarding the effect of manufacturing structure choice on flow time.

Tool planning models for flexible manufacturing systems

Although the tool loading problem for Flexible Manufacturing Systems (FMSs) has been analyzed in the past, the tool planning problem, the basis of tool management, has largely been ignored. In this paper, the interface between tool planning and the FMS loading and routing decisions is analyzed. It is shown that tool policy has a pronounced effect on the flexibility and the planned makespan of an FMS. A tool planning model is developed and integrated into an overall FMS detailed tool loading and part routing procedure. This model while considerably reducing the number of tools required (by 55%) matches the performance of a policy that equips each machine with all tools in terms makespan, routing flexibility, and tool productivity.

A production, distribution and investment model for a multinational company

Considerable research literature exists on production planning, distribution, and investment models. In most cases they have been treated independently in an environment of low inflation rates. Unfortunately, work extending these problems to multinational companies is sparse. This paper develops an integrated production planning, distribution, and investment model for a multinational firm that produces products in different countries and distributes them to geographically diverse markets. Since multinational corporations operate in different countries under varying exchange and inflation rates, varying opportunities for investing, and differing regulations, these factors should be included in the decision process. In the modeling, the paper incorporates these factors and elicits the performance of the model through an example and discusses the results. The results indicate that the exchange rates and initial capacity levels of the firms have significant effects on the production, distribution, and investment decisions, and consequently, on the profit.

A flexible approach to (re)configure Flexible Manufacturing Cells

Abstract Although considerable research literature exists related to Flexible Manufacturing Systems, the issues pertaining to Flexible Manufacturing Cell (re)configuration have largely been ignored. In the design stage, group technology concepts have been used to select parts and machines. However, in the operational stage, if the group technology concept of routing (a priori fixed) based cell formation is employed, is there a guarantee that the part-machine combination (route) selected would result in the overall optimal utilization of the resources? Is the flexibility of the system (as FMCs contain versatile machines) utilized? In this paper, we develop and elicit a procedure that addresses the above issues while (re)configuring FMCs. It utilizes the flexibility of the system when selecting production routes. The procedure developed includes an optimization model and an algorithm to aid in selecting and grouping 1) parts into families and 2) machines into Flexible Manufacturing Cells. The overall benefit of the procedure is that the loading and subsequent scheduling decisions are made simpler, which will help in increasing productivity.

Testing the impact of integrating TQM and DFM on the ability of small to medium size firms to respond to their customer needs

Competing on the basis of time and quality has become the norm since the early 1990s, because cost is no longer the only driving force for competition. This paradigm shift will continue at even a faster rate in the 21st century. Organizations embracing time as a competitive advantage are agile and learning organizations. They always initiate change and are always ready for the challenges that come with it. In this paper, we examine the impact of two of the Time-Based Technologies, hereafter TBTs, on the ability of small to medium size firms to respond to the needs of their customers. In the last seven years or so, Youssef has been studying the impact of TBTs on the operations of manufacturing firms. However, no distinction was made based on the size of the firm. This study utilizes the same database that Youssef used, but as applied only to small to medium size firms. The results of regression analysis showed that the individual as well as the combined effects of Total Quality Management (TQM) and Design for Manufacturability (DFM) have a positive impact on the ability of small to medium size firms to respond to their customer needs. These results have many implications for academics and practitioners.