System dynamics was founded in 1956 by Professor Jay W. Forrester from the Sloan School of Management, Massachusetts Institute of Technology. Forrester mentioned the¡uLevel equation is also known as a first-order differential equation in the branch of mathematics¡K¡K¡v in the book of Principles of Systems. Hence fundamentally system dynamics is a dynamic model in the mathematical model itself, which can also be expressed as a differential equation model. Since the 17th century, differential equation has evolved to become a powerful tool for analyzing the natural processes, and it has developed several research and observation methods, such as the resolution analysis, qualitative analysis and numerical analysis. System dynamics can be applied to solve those kind of problems about high-order, nonlinear, time delay and causal feedback, and these problems are difficult to transform into mathematical models. However, researchers have already addressed many modeling approaches using the basis of system dynamics. In this study, a new transformation method is studied using system dynamics model and transforms it into differential equation model with the aid of mathematical software, applying qualitative analysis and numerical analysis to observe and analyze the differential equation model in order to understand the structure and behavior of the system dynamics model.

Based on the theory of improving the dynamic alignment of balance scorecard strategy in system dynamics, to discuss the dynamic relations among strategic themes, actions and measurements on the strategy map of case, and Using system dynamics model to simulate the scenarios, which usually interference with best decision making. may offer decision-makers more information to take their business actions. This research discovers mainly as: Inspect between the element and the element is linked together the causes and effects back coupling relations in the system, and originally strategy design again by Systems Thinking. The dynamic BSC would be a strategic assessment tools to support managers to make decisions in a large and complicated organization. Through time delay and the effect of negative feedback loops, strategic actions may cause the change of loops, leading to some side effects. As a result, managers may fail to correctly analyze situations and make appropriate decisions, have a complete strategic planning, and have the strategic goal expectably achieved. Policymakers tend to pay too much attention to the variations of the short-time measurements than the long-term structural effect of system. When setting KPI, managers have to consider the influence caused by loops and time delay.

With the development of scientific and technological progress, electronic products are replaced rapidly and the products¡¦ life cycles are shorter than before. Therefore, products¡¦ price are reducing sharply due to market is unpredictable. Electronics Manufacturing Service (EMS) companies are facing competitive pressure with speedy production and price reduction continuously. Moreover, under the phenomenon of the bigger corporation the better operation and economic of scale leading the industry competition, cost and speed are part of key factors to be survival consequently. If medium and small size EMS companies cannot match customers¡¦ requirement, their future to the consequence will be closed or be merged. Hence, to perform an individual company¡¦s competitive ability cannot only rely on internal resource and capability, but also cross boundary between each company. This means companies could win the opportunities by cooperating with customers and supplier in the same supply chain. ¡§Collaborative Commerce¡¨ as productive management skill is for this reason an important research topic recently in business administration. This research applies ¡§System Dynamics Theory¡¨ to collect the relative data and built up a model to achieve the case company¡¦s structure. According to the industry¡¦s characteristic, the researcher simulated and analyzed the incidence of applying collaborative commerce. Moreover, the researcher also discussed the case company¡¦s variance under different dimension, i.e. management strategy, processes of collaborative operation, and benefit anticipated. As a result, applying collaborative commerce provide a good explanation on how it is important for a company to coordinate with external resource, upgrade a company¡¦s management efficiency and adjust a company¡¦s strategy. The conclusions of this research were as followed. Firstly, because of the demand¡¦s uncertainty, inventory was also variance and this was called ¡§Bullwhip Effect¡¨. Moreover, triple collaboration was more efficiency to solve the problem from Bullwhip Effect and reduce the loss occurring by inventory variance. Secondly, the results were not certainly equal between originator and participator. However, Collaborative Commerce can provide effective function for supply chain on productive management. Thirdly, we could monitor the problems of collaboration function while applying dynamical simulation method in practical business and examine the executive outcome. Moreover, this could also be a research instrument when companies analyze Supply Chain Collaboration.

Zugl.: Zürich, Univ., Diss., 2008

This thesis describes and discusses the application of System Dynamics methodology as a basis for formulating diversification strategy and control policies of the largest diversifying cement company in the 'United Kingdom. The problems of the industry such as stagnant growth, cyclic and seasonal variations in cement demand, and overcapacity are described. The formulation of a SD model of the situation which captures these problems together with its equations system are presented. The model also simulates the planning and control processes for the selection, initiation and completion of both expansion and diversification investment projects. It is argued and demonstrated that the fact that these processes consist of feedback loops should and could be utilized for understanding these processes, advancing complementary theoretical concepts, and designing and formulating more 'effective systems and decision rules. An intensive analysis of the model in SD frameworks further supports these arguments. These analyses reveal the nature of the system's dynamic properties and its likely developments, the dynamic and situational nature of diversification effectiveness, and the importance of several diversification decision factors. These analyses also show how complex the formulation of a thorough and effective diversification strategy may become together with the ways and means of dealing with these complexities.. It is concluded that the thrust of an effective diversification lies with the broadening of the conventional theoretical concepts and analysis to include the dynamic characteristics of the system. It is also concluded and shown that System Dynamics methodology can provide a strong analytical basis for achieving these ends.

Today, there is little understanding of how local decisions and disturbances impact the global performance of the supply chain. In this research, we attempt to gain insight about such relationship using multi-resolution hybrid models. To this end, a novel hybrid architecture and methodology consisting of simulation (system dynamic and discrete-event) and optimization modules is proposed. The proposed methodology, applicable to general supply chains, is divided into fours stages: plan stability analysis (Stage I), plan optimization (Stages II), schedule optimization (Stage III) and concurrent decision evaluation (Stage IV). Functional and process models of the proposed architecture are specified using formal IDEF tools. A realistic three-echelon conjoined supply chain system characterized by communicative and collaborative (VMI) configurations is analyzed in this research. Comprehensive SD models of each player of the supply chain have been developed. General conditions of the stability (settings of control parameters that produce stable response) are derived using z-transformation techniques (Stage I), and insights into the behavior of the supply chain are gained. Next, a novel method for the integration of the stability analysis with performance analysis (optimization) is presented (Stage II) by employing the derived stability conditions derived as additional constraints within the optimization models. Next, in Stage III, the scheduling at each chain partner using discrete-event simulation (DES) modeling techniques is addressed. In Stage IV, the optimality of the SD control parameters (from Stage II) and DES operational policies (from Stage III) for each member are concurrently evaluated by integrating the SD and DES models. Evaluation in Stage IV is performed to better understand the global consequence of the locally optimal decisions determined at each supply chain member. A generic infrastructure has been developed using High Level Architecture (HLA) to integrate the distributed decision and simulation models. Experiments are conducted to demonstrate the proposed architecture for the analysis of distributed supply chains. The progressions of cost based objective function from Stages I-III are compared with that from the concurrent evaluation in Stage IV. Also the ability of the proposed methodology to capture the effect of dynamic perturbations within the supply chain system is illustrated.

The purpose of this study is to develop an understanding of the observability of small-scale dynamical Solar System features in meteor orbit radar data, particularly with reference to mean motion resonance effects. Particular focus is placed on the presence of `resonant swarms' in meteoroid streams: the resonant swarm at the 7:2 Jovian mean-motion resonance is used as an example, as it best satisfies radar observability criterion. Furthermore, evidence for this structure exists in visual meteor data. The radar dataset used for this study is that of the Canadian Meteor Orbit Radar (CMOR) as this dataset contains the largest number of meteoroid stream particles. The aim here is to determine whether the Taurid resonant swarm is observable in datasets produced by radars such as CMOR, or what improvements in individual orbital uncertainties are necessary for positive detection to be possible. The observability of the Taurid swarm in radar data depends on the limitations of the radar data (in terms of the individual measurement uncertainties); and on the properties of the resonance itself. Both aspects are investigated in this thesis. A statistical study is first conducted to assess whether evidence for the swarm exists in a dataset containing CMOR Northern and Southern Taurids from the years 2002 to 2007. It is found that the level of variations present is consistent with that expected due to random fluctuations: there is no evidence for a statistically significant resonant feature at the location of the 7:2 Jovian resonance. Additionally, the observability of various sizes of resonant peak for different sizes of dataset and for different levels of measurement uncertainties is investigated by addition of a modelled resonant feature to the data, followed by replacement of individual meteors by Gaussian profiles to simulate the effect of orbital uncertainties. It is clear that the level of broadening resulting from the uncertainties of the CMOR data used will not allow the observation of a resonant peak of the expected size. Detection is expected to be more likely in a `swarm encounter year' (a year in which the geometry between the resonant swarm and Earth is favourable to detection). The velocity uncertainties of a meteor orbit radar (similar to CMOR) need to be improved by a factor of 5 to 10 (relative to the CMOR uncertainties) in order to detect a resonant swarm that is composed of ~30% to ~5% (respectively) of the total number of observed Taurids in a swarm encounter year. An improvement significantly greater than a factor of ~10 is unlikely to result in a significant improvement in the ability to detect the resonant swarm. It is expected that a factor of 10 improvement in radar measurement uncertainties is achievable with the current techniques of radar systems and signal processing. These statistical tests require knowledge of the resonant width of the 7:2 Jovian resonance in semi-major axis, as this provides the size of the resonant feature of interest. Such resonant or libration widths can be determined analytically for orbits with low eccentricities. As Taurid orbits have high eccentricities (e~0.83), a hierarchical N-body integrator is used to examine the dynamics in the region of the 7:2 resonance, and determine a resonant width of (0.047±0.005) AU. To verify this method the standard analytic equations and a semi-analytic method are compared (at low eccentricities) with the numerical resonant width values: the agreement is within 10% for eccentricities below 0.4. It is important to know what proportion of radar Taurids are expected to be resonant in a swarm year in order to evaluate the observability of the swarm in radar data. One important factor that may affect this is the mass distribution of particles in the swarm. This is investigated by ejecting particles in multiple directions from three model comets: the first with a mass and orbit in agreement with those of the current 2P/Encke; the second with 2P/Encke mass and an orbit matching that of the proposed proto-Encke object; and a third with the mass and orbit of proto-Encke. The resulting orbits are examined to determine what proportion will land within the 7:2 resonance, for a range of particle masses and densities. The instantaneous effect of radiation pressure on the orbits of ejected particles is also considered. However, it is difficult to determine accurate capture percentage values due to the uncertainty surrounding cometary ejection mechanisms. Nevertheless, it is found that capture of Taurids into the 7:2 resonance by all comets is possible. Using comparisons between the percentages of visual-sized and radar-sized particles captured, it is determined that in weak swarm years (in which only 20% of visual meteoroids detected are resonant) only 4% to 5% of observed visual Taurids are expected to be resonant. Such a swarm would be on the edge of observability. However, in stronger swarm years (such as 2005), the resonant proportion will exceed that required for detection with a reduction in CMOR measurement uncertainties of a factor of ten.

Many practical problems raise the challenge of making decisions over time in the presence of both dynamic complexity and pronounced uncertainty regarding evolution of important factors that affect the dynamics of the system. In this thesis, we provide an end-to-end implementation of an easy-to-use system to confront such challenges. This system gives policy makers a new approach to take complementary advantage of decision analysis techniques and System Dynamics by allowing easy creation, evaluation, and interactive exploration of hybrid models. As an important application of this methodology, we extended a System Dynamic model within the context of West Nile virus transmission in Saskatchewan.

Housing -as a special product- distinguishes the behaviour of its demand and supply. An imbalance of housing supply against demand can be a crucial part of economic crises, as happened in Thailand between 1996 and 1997. Can the housing market be controlled in a robust and rigid system? A secure market depends on balancing demand and supply dynamics; therefore, any demand has to be quantified. This research demonstrates how housing demand can be modelled by using a System Dynamics approach. This modelling concept has been set up, using the root causes which generate housing demand. Causal factors which influence housing demand are collated, and mapped. A model simulating housing demand was developed. Keys to this are demographic, social and economic factors. This model is presented with a view to pursuing new approaches for housing demand modelling. Conceptual ideas are developed on how to quantify housing demand, and the result of the simulation can then be used as a basis for policy and decision making in housing markets. The housing demand model developed from this research depends on many interrelated factors. These factors can be categorized into three broad groups, following precedent set by a review of available literature. Initial factors included demographics which deal with population number, age structure, including migration, birth and death rate. Next, social factors, in terms of marriage, divorce and splitting-household rate (i.e. household formation rate) play a major role in creating

Zugl.: Erlangen, Nürnberg, University, Diss., 2006.