A Survey of Agent-Based Modeling Practices (January 1998 to July 2008)

In the 1990s, Agent-Based Modeling (ABM) began gaining popularity and represents a departure from the more classical simulation approaches. This departure, its recent development and its increasing application by non-traditional simulation disciplines indicates the need to continuously assess the current state of ABM and identify opportunities for improvement. To begin to satisfy this need, we surveyed and collected data from 279 articles from 92 unique publication outlets in which the authors had constructed and analyzed an agent-based model. From this large data set we establish the current practice of ABM in terms of year of publication, field of study, simulation software used, purpose of the simulation, acceptable validation criteria, validation techniques and complete description of the simulation. Based on the current practice we discuss six improvements needed to advance ABM as an analysis tool. These improvements include the development of ABM specific tools that are independent of software, the development of ABM as an independent discipline with a common language that extends across domains, the establishment of expectations for ABM that match their intended purposes, the requirement of complete descriptions of the simulation so others can independently replicate the results, the requirement that all models be completely validated and the development and application of statistical and non-statistical validation techniques specifically for ABM.Agent-Based Modeling, Survey, Current Practices, Simulation Validation, Simulation Purpose

Strategic Decision Facilitation: Supporting Critical Assumptions of the Human in Empirical Modeling of Pairwise Value Comparisons

Modeling human decision-making is difficult. Decision-makers are typically primed with unique biases that widen the confidence interval of judgment. Therefore, it is important that the human process in the system being modeled is designed to alleviate damaging biases and assumptions in an effort to increase process consistency between decision-makers. In this experiment, it is hypothesized that coupling specific decision-facilitation methods with a specific scale range will affect the consistency between decision-makers. This article presents a multiphase experiment that examines a varying presentation mode as well as scale range to determine how value is determined in subsequent pairwise comparisons of alternatives against specific requirements. When considering subject value ratings of the expected rank order of alternative subgroups (indicating strong criteria independence), results show that subjects used consistent comparison ratios regardless of the scale range. Furthermore, when comparing the subgroups of expected rank order responses to the subgroups of biased responses, although ratios were different, the same general trend of comparison existed within subgroups. Providing evidence that careful selection of the presentation mode can facilitate more consistent value comparisons between compatible decision-makers allows for the identification of and adjustment of disparities due to bias and potential lack of incremental scaling detail. Furthermore, by creating decision processes that render more consistent cognitive behavior between decision-makers, tighter confidence intervals can be obtained, and critical assumptions can be validated

Enhancement of winter maintenance material ordering and inventory

"March 2009."; Includes bibliographical references (p. 99-100).; Final report.; Performed by Wright State University, Dept. of Biomedical, Industrial and Human Factors Engineering, sponsored by Ohio Dept. of Transportation and Federal Highway Administration under state job no.; Harvested from the web on 12/9/13Expenditures for winter maintenance materials total nearly $20 million annually. During an average winter ODOT uses approximately 666,000 tons of rock salt and has the capacity to store roughly 617,000 tons of material at various locations. Each year, each county in Ohio establishes a contract through ODOT with a salt vendor before the winter season and that vendor supplies all garages in the county for the entire season. In order to develop a systematic salt inventory management strategy that achieves the statewide goals for safety, this project developed ordering guidelines for each county that specifies when to order and how much to order based on an (R, S)-inventory guideline. These guidelines take into account the history of usage and deliveries in a county, as well as the monthly variation in usage. The inventory guidelines developed for the different areas of Ohio are based on a weather regression model for the major cities/counties in the state relating usage to weather. The guidelines were tested and refined using a computer simulation methodology. The resulting guidelines are compared to the current ODOT guidelines for inventory, as well as compared to the county storage capacities to develop recommendations. The project also developed design concepts for inventory monitoring to support effective ordering

Strengthening Criteria Independence through Optimization of Alternative Value Ratio Comparisons

Every decision maker’s internal scale is different based on a myriad of possible factors unique to that decision maker. Conflicting criteria within and between alternatives in multicriteria decision making can create negative effects within the weighting schemes and amplify preference biases and scale disparities between decision makers in a group decision context. Additionally, the weighting of group decision-making frameworks can intensify the already skewed criteria values. When making judgments against requirements, it may be preferable to reduce scale trend distortions between decision makers as much as possible. Previous research supports that certain information presentation modes can significantly reduce preference bias and strengthen criteria independence against requirements through cross alternative anchoring. This paper expands that research and proposes a new optimization model for strengthening criteria independence and consensus in group decision making. Initial results indicate the proposed optimization model can significantly reduce scale distortions and smooth comparative alternative value trends between decision makers toward strengthened group consensus. Furthermore, results support the potential and opportunity for semiautonomous group consensus processes

Strengthening Criteria Independence through Optimization of Alternative Value Ratio Comparisons

Every decision maker’s internal scale is different based on a myriad of possible factors unique to that decision maker. Conflicting criteria within and between alternatives in multicriteria decision making can create negative effects within the weighting schemes and amplify preference biases and scale disparities between decision makers in a group decision context. Additionally, the weighting of group decision-making frameworks can intensify the already skewed criteria values. When making judgments against requirements, it may be preferable to reduce scale trend distortions between decision makers as much as possible. Previous research supports that certain information presentation modes can significantly reduce preference bias and strengthen criteria independence against requirements through cross alternative anchoring. This paper expands that research and proposes a new optimization model for strengthening criteria independence and consensus in group decision making. Initial results indicate the proposed optimization model can significantly reduce scale distortions and smooth comparative alternative value trends between decision makers toward strengthened group consensus. Furthermore, results support the potential and opportunity for semiautonomous group consensus processes

An Agent Based Model of Passenger Boarding for Examining Commercial Aircraft Boarding Strategies

Excerpt: We use an agent-based simulation methodology to study airline passenger boarding using measures that reflect both the customer experience and airline efficiency perspective. This approach supports exploration of models of actual aircraft used in practice and detailed modeling of passenger dynamics. This paper discusses the modeling approach and a set of experiments comparing several boarding strategies from practical settings as well as the literature