On-line model based reconfiguration is generally used to improve the ability of a system to tolerate faults. Recovery after fault occurrence relies on allowing the system to proceed with its mission from a new known nominal state. In this paper, we consider on-line reconfiguration from a novel point of view, having in mind to use reconfiguration actions to disambiguate the tracked estimated sys...

This paper presents a case study in the design and implementation of a discrete event system (DES) of real-world complexity. Our DES plant is a flexible manufacturing system (FMS) laboratory model that consists of 29 interacting components and is controlled via 107 digital signals. We apply a hierarchical and decentralised supervisor design method from earlier work and implement the resulting s...

Stochastic Flow Models (SFMs) form a class of hybrid systems used as abstractions of complex Discrete Event Systems (DES) for the purpose of deriving performance sensitivity estimates through Infinitesimal Perturbation Analysis (IPA) techniques when these cannot be applied to the original DES. In this paper, we establish explicit connections between gradient estimators obtained through a SFM an...

This work describes the research conducted in the quest for designing better software for discrete-event system (DES) control. The think-aloud data from an exploratory observational study of solving DES control problems contributed to the formulation of a list of recommendations on how to design and improve DES software. These observations, together with other relevant research, led to the prop...

Analogous to the identification of continuous dynamical systems, identification of discrete-event systems DESs consists of determining the mathematical model that describes the behaviour of a given ill-known or eventually unknown system from the observation of the evolution of its inputs and outputs. First, the paper overviews identification approaches of DES found in the literature, and then i...

System Dynamics modeling and Discrete Event Simulation both can be used to model corporate business decisions. However, there seems to be little dialog between the two communities of modelers. For instance, at the recent WinterSim simulation conference in Washington, DC, there were no presentations of System Dynamics models. Discussions held by the author with a number of practitioners in each ...

A structural decentralised control of discrete-event system (DES) is employed for a simulation study of a sequence control of cleaning-in-process of chemical batch plant. Due to the number of states of the whole plant model is too big, the whole plant has subdivided into smaller sizes and in the local level, the DES models for the local plant and local specifications are established. The condit...

Hybrid control systems can arise when a discrete event system is used to supervise the behaviour of continuous-state systems. In this context, tlie DES supervisor manipulates syiiibols which are representative of events occuring within the plant’s state space. An important issue in the design of such control systems concerns conditions under which such symbolic manipulations are sufficient to a...

Adherence to wait time benchmark targets for the diagnosis and initiation of interventions rheumatoid arthritis is crucial in altering disease trajectory. We analysed impact maximum guarantee (MWTG) policy routing referrals initial rheumatologist consults on waiting service costs. modelled a central intake system rheumatology clinic as discrete event simulation (DES) model. Using data from inpu...