This paper reports on the culmination of a two year project to facilitate smart growth planning in the Las Vegas, Nevada metropolitan area. Using a group model building process, representatives of key municipal entities and resource management agencies developed a model for examining the potential effects of changes in land use and transportation planning on air quality, traffic congestion, and other quality of life factors. The model and the process both contributed significantly to broadening systems thinking capacity in regional planning. The model supports system-based policy evaluation and the process created a common systems language among the more than 20 land use, transportation, and air quality planners in the group. The model represents regional links between population, transportation infrastructure, land use characteristics, and air pollution. Model analysis shows that the most powerful tool for achieving policy objectives is a combination of land use design and transportation infrastructure that reduces the average number of trips per day and distance per trip. This paper describes the model, results of the analysis, and effects of the group model building process on the participants.
This paper analyses different feedback processes arising from physical and human capital accumulation as well as from technological change, which are considered general factors to promote the growth in any economy by economic literature. A dynamic system is constructed to explain the relative influence of these factors on the rate of economic growth in a generic economy. The development of the model requires to analyse different interactions among variables linked to decisions of the agents that participate in the economy, particularly certain variables associated to the labour market are examined. Using a system dynamics simulation the conditions under which a smaller number of hours devoted to the labour market could imply a greater labour productivity are characterized.
Here, a systems dynamics approach combines the environmental, economic and social aspects of intensive shrimp farming to construct a sustainability forecast. Intensive shrimp farming threatens to cause irreversible damage to water and land resources. High initial investments required are risky to small start-up farmers as ponds are prone to self contamination within a few years. This study is based in Ninh Thuan, one of the poorest regions in Vietnam. Since 1999, local people started to turn to intensive shrimp farming for quick profits. Causal loop diagrams presented focus on the individual shrimp farms and their collective effect at the municipal level. Modelling on the environmental aspect indicates that the current practice of intensive shrimp farming is not sustainable for Ninh Thuan. A combination of lowered stocking densities, pond cleaning and limitation on the land area converted to shrimp ponds will be beneficial for the local community in the long term.
The cobweb model of competitive market dynamics has been examined in the form of system dynamics model. Separation of the structure elements and introduction of anticipative hyperincursive algorithm was used for transformation of the classical cobweb model to the accelerator based one. The cyclical response of the system that depends on the demand~supply parameters and eigenvalues of the characteristic equation has been numerically examined. The concept of parameter differentiation and time response of the system is transformed to the periodicity concept where periodicity is the main, driven property of the model. As such this is the key attribute in complex discrete agent-based adaptive anticipatory models. The periodic conditions of the model have been analytically determined by the application of z-transform. The periodicity conditions of the initial map have been preserved in the nonlinear case. By the application of the Lyapunov exponents several stability regions of the nonlinear model were numerically determined.
In our study, we looked at how the impact of disruptions may be modelled in a network of chemical manufacturing plants. Given that the number of plants involved is large, it is not time-feasible to model the operation of each plant in detail. However, after 1st round of quick analysis, we can selectively model the identified critical components in greater detail. Hence, the challenge is to develop a standard template that can capture sufficient information about a plant, to give meaningful result. The standard template can be applied to all plants in our study and also allows a non-technical user to easily represent a new plant and integrate into the existing model.
This paper analyses IT innovation diffusion within communities joined through electronic networks. We draw on qualitative system dynamics, as a methodology of structure and behaviour, in order to understand sustainable IT innovation. The focal point of interest is the adoption-diffusion continuum, from prior use to post-adoptive behaviour, analysed and modelled by means of adaptive structuration based on duality of structure. We draw upon the structurationist system dynamics approach (Reichel A. 2004) and extend it within the context of IT innovation in electronic networks. The aim is to begin the development of an integrative modelling base for IT innovation sustainable diffusion. Cognitive model building, and information processing, are secondary (supporting) epistemic levels, used to aid clarifying issues of collective sociality and group outcomes in innovation uptake. The endeavour undertaken ventures on a holistic route of thought, with the emphasis shift from pure subjectivism to structuration, moving beyond intention toward a system dynamics analysis of IT innovation.
In this paper, a system dynamics model is developed to show how the changes in electricity price affect consumption pattern of the household sector in Iran. Electricity is a kind of commodity that is very difficult and expensive to be stored, if not impossible. It means that energy supply must always meet the demand. In addition, electricity supply capacity must be at least equal to the peak demand. Therefore, in non-peak hours, a portion of the capacity is not used. Peak shifting (shaving) is one of the demand-side load management techniques that can help such a problem. Moreover, subsidized electricity prices cause the power network to be overloaded in many hours of a day. This research has employed the system dynamics methodology, to analyze structure of consumption in household sector. First, the sector is divided into three income groups, including Low-income, Medium-income and High-income. Then, load pattern of each group is modeled by a bottom-up method, which is based on a fuzzy approach. The proposed model facilitates to investigate how different pricing and subsidizing scenarios can affect the consumption pattern to reshape it by shifting peak hours and/or reducing total consumption.
This article presents the problem related to the sustainability of natural resources, in particular the common-pool resources, approached from the System Dynamics perspective and Collective Action Theory. It is stated that the rationality that makes cooperation possible among individuals is shared by these two research fields, and it is presented in this document as the fundamental source to propose preliminary orientations to design simulation games that foster a sustainable use of resources by means of the strategies that make cooperation possible.
An immigration reception house which has the aim to deal with both first aid problems (food and bed) and health and social needs (medical and social services) involves many variables with a high level of interaction, hence a complex system. In order to manage such an infrastructure which can host a limited number of immigrants with different type of characteristics (Status single(male/female), part of a family, ; Geographic provenience- Europe, Africa, Asia, ; Religion- Christian, Moslem, ; ) offering a selected number of services is not an easy job.On the base of a enlarged project sponsored by the department of social activities of Lazio Region (the region which includes Rome city) aiming to train and supply tools to a number of intercultural mediators a system dynamics model has been developed both to analyse and better understand the overall immigration reception process and to create a sort of flight simulator in order to evaluate, in advance, some decision effects over possible scenarios.The paper will describe both the structure of the model which has been developed to embed, as much as possible, the whole process and a set of results produced in reply of a set of what-if analysis.
The paper describes a game called, the supply net game, built around the structure of a production supply network based on the anchoring and adjustment heuristic which is known as the one people use to make inferences about uncertain events. The game involves four players where everyone manages his manufacturing unit that consists of four production lines which proceed to the joint development of products with the other units. While planning production and controlling inventories, every person should try to minimize the costs caused by both holding items on stock and being in an out-of stock situation. The paper stresses the valuable impact and contribution of management games for management and engineering education in general and particularly the significance of learning implicit skills as well as gaining insight in inventory control and management of complex distributed production systems such as the system dynamics production network model introduced and analyzed in the paper. The game will be used later in a controlled experiment which is not under the scope of this paper.