A 3D immersive discrete event simulator for enabling prototyping of factory layouts

There is an increasing need to eliminate wasted time and money during factory layout design and subsequent construction. It is presently difficult for engineers to foresee if a certain layout is optimal for work and material flows. By exploiting modelling, simulation and visualisation techniques, this paper presents a tool concept called immersive WITNESS that combines the modelling strengths of Discrete Event Simulation (DES) with the 3D visualisation strengths of recent 3D low cost gaming technology to enable decision makers make informed design choices for future factories layouts. The tool enables engineers to receive immediate feedback on their design choices. Our results show that this tool has the potential to reduce rework as well as the associated costs of making physical prototypes

Modelling drivers' car parking behaviour using data from a travel choice simulator

This paper reports on models developed from data collected using the PARKIT parking choice simulator. PARKIT provided an experimental environment in which drivers’ choice of car parks, and of the routes chosen to reach them, could be observed and the influence of different levels of parking-stock knowledge (derived from experience or from information provided via roadside message signs) monitored. Separate models were estimated for the drivers’ initial choice of car park and for their revision of that choice as their journey progresses and they learn about actual conditions. The importance of price, walking time and driving distance is confirmed but the addition of variables describing the drivers’ choices on previous days, their expectations and their immediately preceding route-choice, greatly improved the models’ explanatory power. It is noted that variables such as these are not generally considered because they are rarely available to the modeller. Different discrete choice model structures were found to be appropriate for different decisions. Route choice was represented as an exit-choice model (whereby each journey is treated as a sequence of decisions – one at each intersection encountered). The paper discusses the incorporation of these choice models into a network assignment model and concludes that much of the power of the choice models is lost if the network model is not able to support use of information about travellers’ socio-economic characteristics and knowledge of the network and about the detailed network topology

Case study based approach to integration of sustainable design analysis, performance and building information modelling

This paper presents a case study based research of both the method and technology for integration of sustainable design analysis (SDA) and building information modelling (BIM) within smart built environments (SBE). Level 3 BIM federation and integration challenges are recognised and improvements suggested, including issues with combining geometry and managing attribute data. The research defines SDA as rapid and quantifiable analysis of diverse sustainable alternatives and ‘what if’ scenarios posed by a design team and client during the early stages of the project, where the benefits of correct decisions can significantly exceed the actual investment required. The SDA concept and BIM integration findings are explained through a convergence from conceptualisation to calculation stages, emphasising the importance of an iterative over a linear approach. The approach allowed for a multitude of “what if” scenarios to be analysed, leading to more informed sustainable solutions at the right stages of the project development, with a generally lower level of detail (LOD) and computational/modelling effort required. In addition, the final stage of Building Regulations Part L compliance calculations was reached with a lot greater level of certainty, in terms of its requirements. Finally, a strategy for long term performance monitoring and evaluation of the building design in terms of its environmental sustainability is presented, via integration between BIM and SBE (Smart Built Environment) technologies

Using simulation gaming to validate a mathematical modeling platform for resource allocation in disasters

The extraordinary conditions of a disaster require the mobilisation of all available resources, inducing the rush of humanitarian partners into the affected area This phenomenon called the proliferation of actors, causes serious problems during the disaster response phase including the oversupply, duplicated efforts, lack of planning In an attempt to reduce the partner proliferation problem a framework called PREDIS (PREdictive model for DISaster response partner selection) is put forward to configure the humanitarian network within early hours after disaster strike when the information is scarce To verify this model a simulation game is designed using two sets of real decision makers (experts and non-experts) in the disaster Haiyan scenario The result shows that using the PREDIS framework 100% of the experts could make the same decisions less than six hours comparing to 72 hours Also between 71% and 86% of the times experts and non-experts decide similarly using the PREDIS framewor

Shocks in coupled socio-ecological systems: what are they and how can we model them?

Coupled socio-ecological systems (SES) are complex systems characterized by self-organization, non-linearities, interactions among heterogeneous elements within each subsystem, and feedbacks across scales and among subsystems. When such a system experiences a shock or a crisis, the consequences are difficult to predict. In this paper we first define what a shock or a crisis means for SES. Depending on where the system boundary is drawn, shocks can be seen as exogenous or endogenous. For example, human intervention in environmental systems could be seen as exogenous, but endogenous in a socio-environmental system. This difference in the origin and nature of shocks has certain consequences for coupled SES and for policies to ameliorate negative consequences of shocks. Having defined shocks, the paper then focuses on modelling challenges when studying shocks in coupled SES. If we are to explore, study and predict the responses of coupled SES to shocks, the models used need to be able to accommodate (exogenous) or produce (endogenous) a shock event. Various modelling choices need to be made. Specifically, the ‘sudden’ aspect of a shock suggests the time period over which an event claimed to be a shock occurred might be ‘quick’. What does that mean for a discrete event model? Turning to magnitude, what degree of change (in a variable or set of variables) is required for the event to be considered a shock? The ‘surprising’ nature of a shock means that none of the agents in the model should expect the shock to happen, but may need rules enabling them to generate behaviour in exceptional circumstances. This requires a certain design of the agents’ decision-making algorithms, their perception of a shock, memory of past events and formation of expectations, and the information available to them during the time the shock occurred

12th CIRP Conference on Computer Aided Tolerancing

The purpose of this paper is to decipher the process of modelling driving to the product behaviour simulation. A simple example of simulation, tolerance stackup, allows illustrating this process. The tolerance stackup is used daily in industry, however, designers do they know exactly what they do? Are they aware of the assumptions they are introducing? To answer to these questions, concepts of GeoSpelling and of GPS ISO standards such as skin model, operations, operators and other concept are introduced such as finite and infinite models