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- Type:
- Document
- Date Created:
- 1994
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, c060552994c1527f70693734935660f1, and fe35db792b573af835d96e6eba4759cd
- Description:
- One of the advantages commonly put forward in support of the system dynamics methods is that managers find it difficult to trace dynamic consequences of cause and effect relationships even in simple systems. While this may be intuitively appealing as one of the justifications for existence of system dynamics, there is a need to accumulate a body of evidence which results from putting this assertion to the test. The paper reports the findings from a questionnaire which has been administered to over one hundred undergraduates and postgraduates covering a range of business management specialisms. Respondent were asked to decide between two manufacturing technologies, exhibiting quite dissimilar cost structures, with a view as to their future profitability under four different demand scenarios. The questionnaires were administered twice with a three month gap between during which the answers to the first one were revealed, and on the second occasion the rubric was altered to incorporate feedback into the situation described. The competing technologies and their associated cost structures reflect very real policy choices and so the outcome of the exercise has a message for manufacturing industry as well as the system dynamics community.
-
- Type:
- Document
- Date Created:
- 1994
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, c060552994c1527f70693734935660f1, and fe35db792b573af835d96e6eba4759cd
- Description:
- Maintenance management has become a field of important development according to the operating needs of production planning systems and the impact of new technologies in the industry. The processes of production flow creation and inventory control in the modern factories lead to a more sophisticated maintenance system to ensure low failure rates and reduce accordingly failures consequences, which is a must in these kinds of environments to meet the production schedules. In this paper a maintenance system is modelled to study the effects of different policies that can be applied to reach above mentioned targets. Moreover the conditions required to create a continuous improvement mechanism for the system are analyzed. Model validation and simulation results are obtained and presented for a real problem in the Spanish industry.
-
- Type:
- Document
- Date Created:
- 1994
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, c060552994c1527f70693734935660f1, and fe35db792b573af835d96e6eba4759cd
- Description:
- Model conceptualisation is the most difficult system dynamics skill to acquire, practice and teach. The advent of user friendly simulation tools; STELLA and ithink, have made the task of model constructions and use much easier. Model conceptualizations by contrast remains as difficult server as ever. Experiences in training managers in system dynamics show that it is a relatively simple task to turn complete beginners into competent and confident simulators. The capability to recreate a model from ithink map and in a written description of operating policies is quickly acquired, as is the ability of modifying that model set to test out possible solution to problematic behavior. The problem arises when these proficient simulators are asked to conceptualize a simple two loop model from a problem descriptions, presented in the form of a newspaper article. This task is found very difficult by most course members. The paper describes the development of a new technique to assist with the model conceptualisation process. The method integrates archetypes and their corresponding generic Models into a framework that helps modellers move from a problem descriptions to a first past ithink model and/or casual map. An application of the method, to aid conceptualisation of a model of Government funding of housing association is described.
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- Type:
- Document
- Date Created:
- 1994
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, c060552994c1527f70693734935660f1, and fe35db792b573af835d96e6eba4759cd
- Description:
- This paper discusses the dynamic simulation model of the New Zealand wine industry which is being developed at Victoria University to examine the impact of environmental and policy changes on the short and long term behavior of the industry. It is highly aggregated model which includes sectors for: planting and harvesting of grapes; production, exports and imports of wine; stock movements and financial flows. The model provides a policy making framework for the analysis of changes in grape yields, climatic conditions, excise duty on domestic consumptions, minimum grower returns, exchange rate movement and international competitiveness.
-
- Type:
- Document
- Date Created:
- 1994
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, c060552994c1527f70693734935660f1, and fe35db792b573af835d96e6eba4759cd
- Description:
- The study analyzes the impact information network within the waste recycling market on the performance of public policies designed to develop the recycling market. Two typical policies are reviewed with an experimental procedure of partial and whole model tests. A system Dynamics model of waste recycling market is used as a laboratory setting for this study. The research findings suggests that well-intentioned policies can inadvertently lead to dysfunctional performance within a localized information environment. Delayed and distorted information feedback in the multi-stage structure of the recycling market further complicates problematic policy outcome, or market instability. This study proposes an information policy of integrating vertically the information network in the recycling market in order to improve the performance of market development policies
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- Type:
- Document
- Date Created:
- 1994
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, c060552994c1527f70693734935660f1, and fe35db792b573af835d96e6eba4759cd
- Description:
- We investigate parts supply from one supplier to a manufacturer who operates a very variable final assembly schedule with kanbans for parts supply to the production line from suppliers. The information flow includes kanbans for resupplying the line from the factory store and restocking the factory store from the supplier, one week ahead forecasts of parts requirements, 8-week ahead requirements and updates orders supplied weekly, and a six month MRP schedule supplied fortnightly. The supplier uses these to schedule raw material preparation, initial assembly on a bottleneck machine, and finishing. This is challenging given the conflicts between the pieces of information. We investigate ways to improve total system performance, particularly inventory levels and easier production scheduling of critical machines, given the delays and structure of the system, using system dynamics models built in ithink! Kanban numbers can be reduced without risking production interruptions. The one week ahead forecasts offer little useful information to the supplier. Shifting to a simpler scheduling mechanism for the initial assembly is helpful. We have investigated two processes in the manufacturing logistics system, parts flow internal to the manufacturer and to the supplier, and the linkage between parts usage by the manufacturer and parts production by supplier. They can be simplified and improved, reducing inventory holding and hence cost, without compromising the overall responsiveness of the manufacturer which is a distinctive competitive characteristic. Simplified information flow processes allow for easier, better operation of total system.
-
- Type:
- Document
- Date Created:
- 1994
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, c060552994c1527f70693734935660f1, and fe35db792b573af835d96e6eba4759cd
- Description:
- This paper contemplates the prospect of the complementary use of hard, soft, and critical systems methodologies, becoming a more established practice among the diverse company of operational researchers and management scientists in academic, commerce and government, who have been trained in systems thinking and apply its language and concepts in dealing with organizational problems.
-
- Type:
- Document
- Date Created:
- 1994
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, c060552994c1527f70693734935660f1, and fe35db792b573af835d96e6eba4759cd
- Description:
- Privatization of most enterprises in Eastern Europe is considered essential for the democratic form of government to survive over an extended period. The dynamics of the privatizations processes and of management development are very important but they have received very little attention. They are crucial to the success of the attempted conversion of the system in that part of the world. This is stunning because of the several billion ECU's and U$S spent on economic and management advice to the countries in the area. This paper explores the dynamics of management development to meet the needs as markets are freed and companies are privatized. Particular attention is directed at the fact that many needed skills essential to success may not be taught in the normal management school programs. From this observation emerges the need for a program of management development uniquely designed for recently privatized companies and for those soon to go through the process. In addition the conclusions contribute insights to the current debate whether to privatize all corporations within a very short period or whether to proceed more gradually.
-
- Type:
- Document
- Date Created:
- 1994
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, c060552994c1527f70693734935660f1, and fe35db792b573af835d96e6eba4759cd
- Description:
- An effort has been made to develop a system dynamics simulation model for soybean production in India. Soybean has been a relatively new introduction to Indian agriculture as a cash crop. Soybean industry in India is typified by high (1520\%) annual growth in area as well as production. It is also capacity as compared to the annual productions. Soymeal has been a major earner of foreign exchange for the country with advancing years. The model presented here analyses the mechanics of flow of area between various crops options, productivity of soybean and competing corps, annual production, prices and the benefitcost ratio. The values of constants were determined through survey of farmers and expert opinion poll. Policy options have been analysed with the objective of higher profitability for the growers in the long run.
-
- Type:
- Document
- Date Created:
- 1994
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, c060552994c1527f70693734935660f1, and fe35db792b573af835d96e6eba4759cd
- Description:
- The global climate is a large complicated system with many feedback loops connecting the different sub-systems. In recent years there has been an increase in the public's awareness of global warming and the greenhouse effect. The public understands that there is some connection between the human emission of greenhouse gases and global climate change. Experts in this field have been analyzing these connections for years and are still unable to give definitive answers to questions concerning the direct link between emissions and temperature change. Policy makers have a desire to intervene in order to limit the amount of emissions. At this point in time available answers are under debate and are unclear, or the model used by the scientific community are too complicated for policy makers to understand. The purpose of this global warming model is to be small, conceptually clear, and accessible to nonscientists. The model contains all of the feedback loops hypothesized in the scientific literature. However, due to its small size it is aggregated to a global level. This level of aggregation will help to make the model more understandable for policy makers. The global aggregation will allow policy makers to focus upon the global effects rather than the details of the climate system.