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第165行： − + + − System dynamics has found application in a wide range of areas, for example [[Population dynamics|population]], agriculture<ref>F. H. A. Rahim, N. N. Hawari and N. Z. Abidin, “Supply and demand of rice in Malaysia: A system dynamics approach”, International Journal of Supply Chain and Management, Vol.6, No.4, pp. 234-240, 2017.</ref>, [[Ecosystem model|ecological]] and [[Economics|economic]] systems, which usually interact strongly with each other. − − System dynamics has found application in a wide range of areas, for example population, agriculture, ecological and economic systems, which usually interact strongly with each other. − − 系统动力学在人口、农业、生态和经济系统等各个领域都有着广泛的应用，这些领域之间往往存在着强烈的相互作用。 − − − − − − System dynamics have various "back of the envelope" management applications. They are a potent tool to: − − System dynamics have various "back of the envelope" management applications. They are a potent tool to: − + − + − + − + − − − − − − − − − − − − − − Computer software is used to [[computer simulation|simulate]] a system dynamics [[model (abstract)|model]] of the situation being studied. Running "what if" simulations to test certain policies on such a model can greatly aid in understanding how the system changes over time. System dynamics is very similar to [[systems thinking]] and constructs the same [[causal loop diagram]]s of systems with feedback. However, system dynamics typically goes further and utilises simulation to study the behaviour of systems and the impact of alternative policies.<ref name="SysDynSociety">[http://www.systemdynamics.org/ System Dynamics Society<!-- Bot generated title -->]</ref> − − Computer software is used to simulate a system dynamics model of the situation being studied. Running "what if" simulations to test certain policies on such a model can greatly aid in understanding how the system changes over time. System dynamics is very similar to systems thinking and constructs the same causal loop diagrams of systems with feedback. However, system dynamics typically goes further and utilises simulation to study the behaviour of systems and the impact of alternative policies. − − 用计算机软件对所研究的情况进行了系统动力学模型的仿真。在这样的模型上运行“如果”模拟来测试某些策略可以极大地帮助理解随着时间的推移系统如何变化。系统动力学与系统思维非常相似，构造了具有反馈的系统相同的因果循环图。然而，系统动力学通常走得更远，利用模拟来研究系统的行为和替代政策的影响。 − − − − − − System dynamics has been used to investigate resource dependencies, and resulting problems, in product development.<ref name="Repenning:2001kx">{{cite journal |last=Repenning |first=Nelson P. |year=2001 |title= Understanding fire fighting in new product development |journal= The Journal of Product Innovation Management |volume= 18 |issue=5|pages= 285–300|doi= 10.1016/S0737-6782(01)00099-6|url= https://dspace.mit.edu/bitstream/1721.1/3961/2/Tilting_v40-web.pdf |hdl=1721.1/3961 }}</ref><ref name="Repenning:1999ng">Nelson P. Repenning (1999). ''Resource dependence in product development improvement efforts'', [[MIT Sloan School of Management]] Department of Operations Management/System Dynamics Group, Dec 1999.</ref> − − System dynamics has been used to investigate resource dependencies, and resulting problems, in product development. − − 系统动力学已经被用来研究产品开发中的资源依赖，以及由此产生的问题。 − − − − − − A system dynamics approach to [[macroeconomics]], known as ''[[Minsky (economic simulator)|Minsky]]'', has been developed by the economist [[Steve Keen]].<ref name="SForge"> [http://sourceforge.net/blog/january-2014-potm/ SourceForge] Minsky - Project of the month January 2014. Interview with Minsky development team. Accessed January 2014</ref> This has been used to successfully model world economic behaviour from the apparent stability of the [[Great Moderation]] to the sudden unexpected [[Financial crisis of 2007–08]]. − − A system dynamics approach to macroeconomics, known as Minsky, has been developed by the economist Steve Keen. This has been used to successfully model world economic behaviour from the apparent stability of the Great Moderation to the sudden unexpected Financial crisis of 2007–08. − − 经济学家史蒂夫•基恩(Steve Keen)提出了一种宏观经济学的系统动力学方法——明斯基(Minsky)。从“大缓和”(Great Moderation)时期表面上的稳定，到2007年至2008年突如其来的金融危机，世界经济行为都成功地运用了这一模型。 − − − − − − ===例子 Example=== − − [[Image:Causal Loop Diagram of a Model.png|thumb|600px|center|Causal loop diagram of a model examining the growth or decline of a life insurance company.<ref name ="Tay Feedback"/>]] − − Causal loop diagram of a model examining the growth or decline of a life insurance company. − − 人寿保险公司的增长或衰退模型的环路图。 − − − − The figure above is a causal loop diagram of a system dynamics model created to examine forces that may be responsible for the growth or decline of [[life insurance]] companies in the [[United Kingdom]]. A number of this figure's features are worth mentioning. The first is that the model's negative feedback loops are identified by ''C's'', which stand for ''Counteracting'' loops. The second is that double slashes are used to indicate places where there is a significant delay between causes (i.e., variables at the tails of arrows) and effects (i.e., variables at the heads of arrows). This is a common causal loop diagramming convention in system dynamics. Third, is that thicker lines are used to identify the feedback loops and links that author wishes the audience to focus on. This is also a common system dynamics diagramming convention. Last, it is clear that a decision maker would find it impossible to think through the dynamic behavior inherent in the model, from inspection of the figure alone.<ref name ="Tay Feedback">Michael J. Radzicki and Robert A. Taylor (2008). [http://www.systemdynamics.org/DL-IntroSysDyn/start.htm "Feedback"]. In: ''U.S. Department of Energy's Introduction to System Dynamics''. Retrieved 23 October 2008.</ref> − − The figure above is a causal loop diagram of a system dynamics model created to examine forces that may be responsible for the growth or decline of life insurance companies in the United Kingdom. A number of this figure's features are worth mentioning. The first is that the model's negative feedback loops are identified by C's, which stand for Counteracting loops. The second is that double slashes are used to indicate places where there is a significant delay between causes (i.e., variables at the tails of arrows) and effects (i.e., variables at the heads of arrows). This is a common causal loop diagramming convention in system dynamics. Third, is that thicker lines are used to identify the feedback loops and links that author wishes the audience to focus on. This is also a common system dynamics diagramming convention. Last, it is clear that a decision maker would find it impossible to think through the dynamic behavior inherent in the model, from inspection of the figure alone. − − 上面的数字是一个系统动力学模型的环路图，这个模型是为了研究可能对英国寿险公司的增长或衰退负有责任的力量而创建的。这个数字的一些特征值得一提。首先，模型的负反馈回路由 c 进行识别，c 代表抵消回路。第二种是双斜线用来表示原因(即箭头尾部的变量)和效果(即箭头头部的变量)之间存在显著延迟的地方。这是系统动力学中常见的因果循环图。第三，较粗的线条用来识别作者希望读者关注的反馈回路和链接。这也是一个常见的系统动力学图表惯例。最后，很明显，决策者不可能仅仅通过对数字的检查来思考模型中固有的动态行为。 − − − − + − # Objective: study of a crank-connecting rod system.<br /> We want to model a crank-connecting rod system through a system dynamic model. Two different full descriptions of the physical system with related systems of equations can be found [[Piston motion equations#Position|here]] {{in lang|en}} and [[:fr:Système bielle-manivelle#Équations horaires|here]] {{in lang|fr}}; they give the same results. In this example, the crank, with variable radius and angular frequency, will drive a piston with a variable connecting rod length. − Objective: study of a crank-connecting rod system.<br /> We want to model a crank-connecting rod system through a system dynamic model. Two different full descriptions of the physical system with related systems of equations can be found here and here ; they give the same results. In this example, the crank, with variable radius and angular frequency, will drive a piston with a variable connecting rod length.+ − 目的: 研究曲柄连杆机构。 通过建立系统动力学模型，对曲柄连杆机构进行建模。在这里可以找到对物理系统和相关方程组的两种不同的完整描述，它们给出了相同的结果。在这个例子中，可变半径和角频率的曲柄将驱动连杆长度可变的活塞。 − # System dynamic modeling: the system is now modeled, according to a stock and flow system dynamic logic.<br /> The figure below shows the stock and flow diagram [[Image:TRUE Piston SFD.png|centre|Stock and flow diagram for crank-connecting rod system 曲柄连杆系统的存量流量图|frame]]+ − System dynamic modeling: the system is now modeled, according to a stock and flow system dynamic logic.<br /> The figure below shows the stock and flow diagram frame − 系统动态建模: 根据存量和流量系统的动态逻辑对系统进行建模。 Br / 下图显示了存量-流量图框架+ + − # Simulation: the behavior of the crank-connecting rod dynamic system can then be simulated.<br /> The next figure is a 3D simulation created using [[procedural animation]]. Variables of the model animate all parts of this animation: crank, radius, angular frequency, rod length, and piston position.+ − Simulation: the behavior of the crank-connecting rod dynamic system can then be simulated.<br /> The next figure is a 3D simulation created using procedural animation. Variables of the model animate all parts of this animation: crank, radius, angular frequency, rod length, and piston position. − 仿真: 可以对曲柄连杆机构的动力学行为进行仿真。 Br / 下一个图形是使用过程动画创建的3D 模拟。模型的变量动画这个动画的所有部分: 曲柄，半径，角频率，连杆长度，和活塞的位置。+ + − + + − 3D [[procedural animation of the crank-connecting rod system modeled in 2|frame]]+ − +
→应用 Application
[[Image:Adaption SFD continuous time.png|centre|连续时间下“新产品采用”模型的动态库存及流程图|frame]]
[[Image:Adaption SFD continuous time.png|centre|连续时间下“新产品采用”模型的动态库存及流程图|frame]]
==应用 Application==
==应用==
系统动力学在人口、农业<ref>F. H. A. Rahim, N. N. Hawari and N. Z. Abidin, “Supply and demand of rice in Malaysia: A system dynamics approach”, International Journal of Supply Chain and Management, Vol.6, No.4, pp. 234-240, 2017.</ref>、生态和经济系统等各个领域都有着广泛的应用，这些领域之间往往存在着强烈的相互作用。
系统动力学有各种各样的“封底”管理应用。它们是一个强有力的工具:
系统动力学有各种各样的“封底”管理应用。它们是一个强有力的工具:
*Teach [[system thinking]] reflexes to persons being coached 向受训者传授系统思维反射
*向受训者传授系统思维反射
*分析和比较关于事物运作方式的假设和'''心智模型 Mental model'''
*对一个系统的运作或决策的结果获得定性的洞察
*在日常实践中认识功能失调系统的原型
*Analyze and compare assumptions and [[mental model]]s about the way things work 分析和比较关于事物运作方式的假设和'''心智模型 Mental model'''
*Gain qualitative insight into the workings of a system or the consequences of a decision 对一个系统的运作或决策的结果获得定性的洞察
*Recognize archetypes of dysfunctional systems in everyday practice 在日常实践中认识功能失调系统的原型
=== 活塞运动实例 Example of piston motion ===
用计算机软件对所研究的情况进行了系统动力学模型的仿真。在这样的模型上运行“如果”模拟来测试某些策略可以极大地帮助理解随着时间的推移系统如何变化。系统动力学与系统思维非常相似，构造了具有反馈的系统相同的因果循环图。然而，系统动力学通常走得更远，利用模拟来研究系统的行为和替代政策的影响。<ref name="SysDynSociety">[http://www.systemdynamics.org/ System Dynamics Society<!-- Bot generated title -->]</ref>
系统动力学已经被用来研究产品开发中的资源依赖，以及由此产生的问题。<ref name="Repenning:2001kx">{{cite journal |last=Repenning |first=Nelson P. |year=2001 |title= Understanding fire fighting in new product development |journal= The Journal of Product Innovation Management |volume= 18 |issue=5|pages= 285–300|doi= 10.1016/S0737-6782(01)00099-6|url= https://dspace.mit.edu/bitstream/1721.1/3961/2/Tilting_v40-web.pdf |hdl=1721.1/3961 }}</ref><ref name="Repenning:1999ng">Nelson P. Repenning (1999). ''Resource dependence in product development improvement efforts'', [[MIT Sloan School of Management]] Department of Operations Management/System Dynamics Group, Dec 1999.</ref>
经济学家史蒂夫•基恩 Steve Keen提出了一种宏观经济学的系统动力学方法——明斯基 Minsky。从“大缓和” Great Moderation时期表面上的稳定，<ref name="SForge"> [http://sourceforge.net/blog/january-2014-potm/ SourceForge] Minsky - Project of the month January 2014. Interview with Minsky development team. Accessed January 2014</ref> 到2007年至2008年突如其来的金融危机，世界经济行为都成功地运用了这一模型。
===例子===
[[Image:Causal Loop Diagram of a Model.png|thumb|600px|center|Causal 人寿保险公司的增长或衰退模型的环路图。<ref name ="Tay Feedback"/>]]
上面的数字是一个系统动力学模型的环路图，这个模型是为了研究可能对英国寿险公司的增长或衰退负有责任的力量而创建的。这个数字的一些特征值得一提。首先，模型的负反馈回路由 c 进行识别，c 代表抵消回路。第二种是双斜线用来表示原因(即箭头尾部的变量)和效果(即箭头头部的变量)之间存在显著延迟的地方。这是系统动力学中常见的因果循环图。第三，较粗的线条用来识别作者希望读者关注的反馈回路和链接。这也是一个常见的系统动力学图表惯例。最后，很明显，决策者不可能仅仅通过对数字的检查来思考模型中固有的动态行为。<ref name ="Tay Feedback">
===活塞运动实例===
#目的: 研究曲柄连杆机构。 通过建立系统动力学模型，对曲柄连杆机构进行建模。在这里可以找到对物理系统和相关方程组的两种不同的完整描述，它们给出了相同的结果。在这个例子中，可变半径和角频率的曲柄将驱动连杆长度可变的活塞。
[[Image:TRUE Procedural Animation.gif|centre|3D [[procedural animation]] of the crank-connecting rod system modeled in 2|frame]]
#系统动态建模: 根据存量和流量系统的动态逻辑对系统进行建模。下图显示了存量-流量图框架:
[[Image:TRUE Piston SFD.png|centre|曲柄连杆系统股票及流程图|frame]]
#仿真: 可以对曲柄连杆机构的动力学行为进行仿真。下一个图形是使用过程动画创建的3D模拟。模型的变量动画这个动画的所有部分: 曲柄，半径，角频率，连杆长度，和活塞的位置。
三维动画[曲柄连杆机构的程序动画，2 | 帧]
[[Image:TRUE Procedural Animation.gif|centre|三维动画:曲柄连杆机构的程序动画|frame]]
==See also==
==See also==