This paper presents one middle term simulations model and its main results. We chose the production systems which produce complex capital goods, for example electrical equipement or household goods. The objective of this type of system is to build up stocks of finished goods which are put at the disposal of the customers. The corresponding macro model was designed by a systemic vision and split into three components which represent the operating, decision and information production sub-systems. The simulation of the generic model has permitted the improvement of system dynamics knowledge. We detected prominent decision loops and some unnecessary loops in production control.
Fuzzy numbers is presented as an alternative to probabilistic methods for the management of uncertainty in system dynamic model. Fuzzy numbers are particularly suitable to represent vagueness and qualitative values. Fuzzy numbers are used during simulation, but due to interactiveness among variables there is a need for global optimization methods. Some examples that illustrate the use of fuzzy numbers, both directly and as a means to represent qualitative values, are shown.
This paper explores the behavior of the gross investment considerig the linear versions and two non-linear versions from Kalecki’s model. This model assumes that there is an average gestation lag of investment and it is formuled by means of a mixed differential-difference equations.
This paper examines the use of a system dynamics modelling technique to enhance the contribution made by cash flow forecasts to decision makers' mental models. It is argued that by making explicit and accessible the dynamic complexity in cash flow relationships, systems dynamics can provide valuable insights for decision making puposes. By permitting the exploration of behavioural responses to perceptions about the financial position of thee business, a richer picture of the decision outcome is developed leading to changes in decision makers perceptions about the riskiness of a proposed course of action. A case study of a commercial organisation is used to illustrate these insights.
Service quality cannot be measured and tested in as straight forward a manner as in manufacturing. This biases serve businesses to focusing on keeping measurable variables-typically, expenses and work flows-in control, while underinvesting in the intangibles of service capacity and service quality. In the long-term, results can be mediocre levels of service quality, poor customers satisfaction, high turnover of service personnel, and ultimately, higher total costs. In this paper we will present an emerging theory of interactions between Service Quality and Service Capacity, relate this theory to past research in both the System Dynamics and Total Quality Management traditions and outline ongoing empirical testing of the theory.
What should every professional dynamicist know? What are the core works defining our field? This survey of the English-language system dynamics literature identifies and summarizes one view of the essential papers, book, games and software programs that have influenced the development of the field. Such a list serves as a means of reflecting on the foundation of current research and practice, thus providing a catalyst for a continuing discussion among system dynamicists on the major themes of the field and the contributions that define them. In presenting this bibliography, the authors encourage other researchers., practitioners and student to add their views to the present effort.
This Paper develops a conceptual model of a collegial system working without external adjudication or an institutional charter governing the conduct of its operations. The model is applicable to many of the academic and research organizations established in the developing countries, which have attempted to emulate the equivalent professional organization in the advanced industrial countries but have achieved low efficacy. The analysis suggests that an unadjudicated collegial system is not sustainable, for it will tend to create an authoritarian administration which will impair the collegial norms and misallocate scarce resources to the activities fueling bureaucratization and expansion of administrative scope, while professional autonomy, innovativeness and self-actualized behavior are suppressed. Professional conduct tends to be more-value rational than the bureaucracy since it is subject to reviews by external peers. Thus, legitimation of referent power is essential to creating value-rational decisions which assure a balanced resource allocation that sustains a collegial system. Limiting scope of the administration through an external scrutiny of its conduct or a charter appears to facilitate this process.
The purpose of this paper is to show that a well-known group of economists known as “Post Keynesians” or “Post Keynesian Institutionalists”, engage in macroeconomic modeling in a way that is strikingly similar to the system dynamics method. It will be argued, therefore, that system dynamics can be used to improve Post Keynesian macroeconomic analysis. In addition, this paper will present an original system dynamics model of macroeconomic growth, instability, and income distribution, that can clearly be classified as Post Keynesian. Of interest is that the model generates, among other behaviors, an economic long wave.