Stephan Onggo

Parallel discrete-event simulation of population dynamics

Research in parallel simulation has been around for more than two decades. However, the number of papers reporting on its application to real world problems is limited. At the 2002 PADS conference, researchers discussed the need to go beyond synchronization and performance issues, and, in particular, to demonstrate that parallel simulation could be used in real world applications outside military and network simulations. Since then, we have seen an increase in the number of papers on the parallel simulation applications in areas such as operations management and the physical sciences. This paper advocates the application of parallel simulation in population dynamics which is often used as the basis for policy planning and analysis. In this paper, we show how the simulation model is implemented using the ¿sik parallel simulation library. We conduct some experiments to measure the simulation performance. The result shows that good event parallelism can be achieved.

Managing the social amplification of risk: a simulation of interacting actors

A central problem in managing risk is dealing with social processes that either exaggerate or understate it. A longstanding approach to understanding such processes has been the social amplification of risk framework. But this implies that some true level of risk becomes distorted in social actors’ perceptions. Many risk events are characterised by such uncertainties, disagreements and changes in scientific knowledge that it becomes unreasonable to speak of a true level of risk. The most we can often say in such cases is that different groups believe each other to be either amplifying or attenuating a risk. This inherent subjectivity raises the question as to whether risk managers can expect any particular kinds of outcome to emerge. This question is the basis for a case study of zoonotic disease outbreaks using systems dynamics as a modelling medium. The model shows that processes suggested in the social amplification of risk framework produce polarised risk responses among different actors, but that the subjectivity magnifies this polarisation considerably. As this subjectivity takes more complex forms it leaves problematic residues at the end of a disease outbreak, such as an indefinite drop in economic activity and an indefinite increase in anxiety.

Improving police control rooms using simulation

Police command and control centres are the main point of contact for the public who require help. Like other areas of UK public services, police forces are set targets for their performance. Some of these targets relate to the speed at which they respond to calls for assistance from the public. In this paper we share our experience in improving the performance of command and control centres of a UK Police Force; a project which started as a classical simulation exercise and ended up with a significant reorganization in a UK Police Force.

Adult Social Care Workforce Analysis in England: A System Dynamics Approach

Changes in demographic and regulations in social care in England are expected to alter the social care landscape and increase pressure on people working in the adult social care sector, especially those who deliver direct care services. While significant work has been done to understand the demand side of the adult social care system, work on the supply side is considerably limited and analysis has been dominated by methods such as macro- and micro-simulation. This paper demonstrates that system dynamics modelling can be used to understand the dynamics of the social care workforce who deliver direct care services in the formal sector, specifically, to identify the main feedback loops that govern the dynamics of the system, to identify sensitive and influential factors, and to show non-linearity in the system. Therefore, system dynamics should play a more important role in the analysis of adult social care system.

Simulation of Career Development in the European Commission

The European Commission (the Commission) employs more than 22,000 officials who provide administrative services to the European Union. In 2003, the Commission introduced a performance appraisal and promotion system based on points that the officials earn each year. In 2006, the Commission realized that the system needed to be revised. To support the review process, the Commission invited tenders for a project to develop simulation models that it could use to project the future performance of the existing system. A team from Lancaster University won the bid and subsequently worked closely with Commission officials to develop a new system. In 2009, the stakeholders in the Commissions performance appraisal and promotion system agreed to implement the improved system. The simulation model is unusual in the field of manpower planning because it models the consequences of appraisal-system rules. It uses novel, accurate, and efficient sampling techniques that are based on regression models of the underlying relationships in the data. The model was a crucial part of renegotiating the appraisal and promotion system and implementing a new system.

A dynamic business model for component-based simulation software

Firms, investors, venture capitalists, market analysts and the government, amongst others, are interested in the future evolution and dynamics of a market as it defines their role/participation or future role/participation. This paper proposes a business model showing how the interactions of various actors in the market influence the demand and supply interaction for an application based software; more specifically component based simulation. In the process we also show how the main stakeholders may gain some financial benefits by adopting the component-based simulation for business decisions in the long run. We identify four main stakeholders: component users, component providers, certification providers, and repository providers. A system dynamic model is built to show the interaction between the two main stakeholders

Behavioural modelling of career progression in the European Commission

Though manpower planning models have been part of OR for many years, and simulation has always been acknowledged as a potential approach, there are few reported applications of its use. In this case-based study we report on a micro-simulation model that exploits the structure of the European Commission’s appraisal and promotion rules, and includes regression-based sampling schemes which allow for non-Normal error terms to represent behavioural factors that led to the need for a new system. With a suitably parsimonious formulation the 20,000 person model runs very effectively, and the transparency associated with simulation proves an important factor in the successful use of the model as the basis for designing a promotion box system that was implemented across the Commission in 2009. The simulation modelling incorporates many Markov-type elements, and we reflect on important lessons learned from this combined use of micro-simulation and Markov-based approaches to manpower modelling.