The purpose of this work is to share the experience using a Poster presentation of projects in System Dynamic (SD). The paper focus in how this didactic resource has been a helpful tool supporting the didactics of SD methodology (process) and at the same time a great resource to share with the students the entire project made by each of the class teams (product).
Key words: Poster, systems dynamics, Project Oriented Learning
The UN Millennium Project (MP) team has conducted a comprehensive cross-country analysis of the interventions and investments required to achieve the Millennium Development Goals (MDGs) . The MP needs-assessment focuses on a number of pilot developing countries, selected on the basis of their low per capita incomes, geographic and political diversity, and record of sound governance. In its analysis, the MP team developed a series of spreadsheet-based models that are used to calculate the cost for the interventions required to achieve the MDGs in the pilot countries . MP methodology is very practical and rich in specific details, but since it relies on exogenous assumptions for economic and demographic growth, it cannot address two issues of interest: (1) the impact of the MDG-related interventions on the economic and demographic development of the country under study and (2) the possible synergies and dissynergies among different MDG interventions. The work described in this paper complements and builds on the work of the MP team by addressing these two important issues and evaluating their implications for MDGs costing and financing. The analysis for this paper was prepared using the Threshold 21 (T21) integrated development model from the Millennium Institute.
The growth of unsolicited commercial email (UCE) imposes increasing costs on organizations and causes considerable aggravation on the part of email recipients. A thriving anti-spam industry addresses some of the frustration. This paper contributes to our understanding of the UCE phenomenon by drawing on scholarly work in areas of marketing and resource ownership and use. Adapting the tragedy of the commons to the email context, we identify a causal structure that drives the direct e-marketing industry. Computer simulations indicate that although filtering may be an effective method to curb UCE arriving at individual inboxes, it is likely to increase the aggregate volume, thereby boosting overall costs. The analysis advances understanding of the digital commons, the economics of UCE, and has practical implications for the direct e-marketing industry.
The government regulation policy, in the mobile phone services market which is characterized by its 'asymmetric' stance, has been provoked debates on many issues amid pros and cons. For that, many previous studies have endeavored to point out the limitations of asymmetric regulations and suggested the improving measure tools, most of previous studies showed common shortcomings. This study aimed at evaluating the government regulation policies over mobile phone market, by analyzing in advance the efficacy of any potential regulation policies, and by estimating the timeliness of the enforcement. To achieve this objective, a simulation model based on the system dynamics methodology was developed to test the impact of governmental regulation policies being enforced under various scenarios of the mix of government policies.
This paper examines a new approach to understanding corporate transparency (or, in reverse, opacity) system, which is used to recognize interconnections existing among firm-related agents how they sanction and monitor each others behaviors, ultimately tuning the activity of a firm in a systematic context. Firm-related agents include internal stakeholders (especially board of directors) and external stakeholders. While former approach individually can only examine corporate transparency/opacity in a one-sided way, we attempted to take on a more holistic and dynamic view using system dynamics. With our new integrative model, we propose a systematic solution to corporate transparency/opacity problems and provide a new means of studying corporate value more transparently than ever before, thus offering a better chance of corporate sustainability and also enhancing corporate value.
A system identification approach is used in order to model and identify the structural relationship
between freight rates in the tanker industry and a set of exogenous inputs. Our motivation results from
the limited data availability and the prohibitive theoretical complexity of economic models for the
evaluation of managerial decisions and risk management. The combination of statistical analysis and
economic insight leads to an innovative multidisciplinary approach for modelling competitive economic
systems. We calibrate the model with real data from 1980-2002, achieve estimation and identification
of the system and fully track the directional changes in freight rates. After conducting performance
evaluation an innovative hybrid model is introduced and system performance is maximized both within
and out-of-sample. Finally we discuss potential uses of this model for policy analysis, managerial
investment decisions and risk management.
In a globally operating company, when a country management team base their opposition to the global product marketing strategy on a System Dynamics simulation tool, the model is definitely to support communication across the management layers in a bottom-up way. To reach out to stakeholders and global management at the HQ, neither of them being familiar with the System Dynamics approach, its not sufficient to provide a technically convincing simulation tool. This paper describes a bottom-up model building initiative and its vital educational component. Building the model with the client had to both grow ownership at the country level, overcome "black-box" attitudes and establish a shared understanding for the approach at the stakeholder level in order to structure the discussion about critical issues beyond trailing market dynamics or covering up by fanciful statistics.
Keywords: Black box, Stakeholder, Ownership
An important class of decision problems involve the selection of a policy in the presence of both uncertainty regarding future eventualities and a system exhibiting complex policy response. Within this paper, we examine the performance benefits of performing strategy selection for such problems using a hybrid modeling approach that combines decision analysis and system dynamics. Within this approach, a modeler uses a decision tree to encapsulate choices, uncertainties, and consequences (the last computed by a system dynamics model). While this hybrid technique offers many additional advantages in terms of expressiveness and the encouragment of systematic investigation of policy space, this paper focuses on the performance gains it provides. In particular, the use of decision trees to represent such decision problems permits the use of dynamic programming, which can dramatically decrease the costs of identifying a preferred policy beyond what is possible by evaluating possible policies in turn. The paper quantifies these performance advantages by means of recurrence relations for arbitrary trees, and derives inductively proven closed-form expressions of performance gain for complete trees. The results suggest that the hybrid method yields speedups exponential in the depth of the tree for both complete and randomly generated trees.
Overreaction to supply shortages can create havoc in supply chains, costing millions of dollars in
excess inventory and manufacturing capacity. In an experiment with the Beer Distribution Game, we
explore overreaction to shortages as a complementary behavioral cause of supply chain instability. As
in previous studies, we find that players ignore the supply line. We find, however, that instead of
overreacting to shortages, players limit the size of their order adjustment while aiming for higher than
necessary inventory level; a policy that is more stable than the linear response suggested in previous
studies. Since an ordering rule that fails to account for the supply line leads to higher than necessary
costs and order amplification, our results suggest that players are not fully rational. However,
evaluating the performance of the estimated policy we find that, given the information cues available,
players show bounded rationality and develop a satisficing replenishment decision rule that minimizes
local cost at the expense of higher upstream cost. We explore the implications of these findings for the
design of information and incentive systems for supply chain management.