Using System Dynamics Method to Determine the Effect of Water Demand Priorities on Downstream Flow

Unconventional risk quantification methods focused on risk assessments only are reviewed. It is shown that all unconventional methods are actually not risk quantification methods being aimed at evaluation of overall project durations and costs. Three methods are reviewed—parametric, artificial neural networks (ANN), and system dynamics. Reasons for high systematic errors and low accuracy of parametric methods are uncovered. They stem from using biased sampling—convenience and judgement samples—as well as from mathematical shortcomings of parametric methods. ANN methodology is positioned as a possible fundamental upgrade for parametric methods. It is shown that the ANN method also depends on quality of used samples. The system dynamics method is introduced to reveal non-linear interactions in project systems based on implications of project rework cycles. It is pointed out that if identified and addressed project risks are factored into the system dynamics modelling the latter could be requalified as a conventional methodology.

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Review of the Evaluation of Urban Sustainable Development

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1073-1076.2610 ◽

2014 ◽

Vol 1073-1076 ◽

pp. 2610-2613

Author(s):

Ling Zhang ◽

Lu Pan Wang ◽

Le He ◽

Hou Chen Li

Keyword(s):

Sustainable Development ◽

System Dynamics ◽

Composite Index ◽

Urban Metabolism ◽

Environmental Aspects ◽

Index Method ◽

Urban Sustainable Development ◽

Development Evaluation ◽

The Relationship ◽

Dynamics Method

City is a kind of synthetic system, which is composed of social, economic and environmental aspects, how to achieve a sustainable development is an important problem for most cities in the world. This paper made a literature review from the composite index method, urban metabolism method and system dynamics method to summary and analysis the urban sustainable development evaluation of existing method. The composite index method is the most concise approach and easy to understand, urban metabolism method can observe the operation of whole city subsystems dynamically, while system dynamics method truly simulates the relationship among city subsystems.

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Improving the Performance of Water Distribution Networks Based on the Value Index in the System Dynamics Framework

Water ◽

10.3390/w11122445 ◽

2019 ◽

Vol 11 (12) ◽

pp. 2445

Author(s):

Mohsen Hajibabaei ◽

Sara Nazif ◽

Robert Sitzenfrei

Keyword(s):

System Dynamics ◽

Water Demand ◽

Environmental Performance ◽

Water Distribution ◽

Distribution Networks ◽

Water Distribution Networks ◽

Average Pressure ◽

Environmental Performance Index ◽

A Value ◽

Per Capita

This study proposes an algorithm for the improvement of water distribution networks (WDNs) performance using system dynamics. In the first part, the hydraulic and environmental performance of WDNs is investigated. The hydraulic performance is assessed based on the pressure of nodes and the flow velocity in pipes. Furthermore, using life cycle assessment, an environmental performance index is proposed to examine the environmental impacts of WDNs. Moreover, in order to evaluate the overall performance in regards to the costs, a value index in the system dynamics framework is proposed. Then, based on the developed framework, improvement strategies for a WDN are assessed by applying scenarios according to constraints and requirements of the network. The considered scenarios are as follows: (1) reducing per capita water demand of the WDN; (2) decreasing the average pressure in the WDN; (3) reducing the mean age of the system by its renewing; and (4) a combination of reducing the per capita water demand and average pressure in the WDN. The results indicate that the best solutions for increasing the value index in this network are: (a) to reduce the pressure of the pressure reducing valves (PRV) from 30 to 28 m; (b) to reduce the per capita water demand by the annual rate of 0.5% and 1% and decreasing the pressure of the PRV valves together. Therefore, it is shown how the developed algorithm is a purposeful approach for evaluating and improving the performance of WDNs based on the value index.

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Analysis of the Granularity of Task Decomposition in Enterprise Alliance Based on System Dynamics

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.314-316.487 ◽

2011 ◽

Vol 314-316 ◽

pp. 487-491

Author(s):

Xian Zhang

Keyword(s):

Qualitative Analysis ◽

System Dynamics ◽

System Dynamics Model ◽

Key Factors ◽

Dynamics Model ◽

Task Decomposition ◽

Proposed Model ◽

Product Manufacturing ◽

Manufacturing Time ◽

Dynamics Method

The influence brought by the granularity of task decomposition on the key factors of enterprise aliance was studied based on system dynamics method. These factors includs inter-restriction, product manufacturing time, collaboration fee, Alliance leader benefit, capability and compatibility. Causality diagram and system dynamics model were established for these factors. This paper also developed a simulation program for the granularity of task decomposition based on the system dynamics model and validated the effectiveness of the proposed model by a qualitative analysis. The results show that it is a workable method to research the granularity of task decomposition in enterprise aliance using system dynamics theory.

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