Fault tree analysis and fuzzy expert systems: Early warning and emergency response of landfill operations

In this paper we argue that Early Warning Systems for engineering facilities can be developed by combining and integrating existing technologies and theories. As example, we present an efficient integration of fuzzy expert systems, fault tree analysis and Worldwide Web technologies to their application in the development of the Landfill Operation Management Advisor (LOMA), a novel early warning and emergency response system for solid waste landfill operations. The aim of LOMA is to provide assistance to landfill managers on their efforts in preventing accidents and operational problems and to help them to develop emergency response plans if these operational problems shall occur. Additional aim is to disseminate information and knowledge to the public on landfill operational problems and their adverse effects. This aim is related to solid waste organizations that have to accord with legislations which are similar to the European Union's EC Directive (2003/4/EC) on Public Access to Environmental Information. When using LOMA, the user first describes the working conditions at the landfill. Then, based on this description, LOMA informs user about the potential operational problems. Afterwards, it analyzes the operational problems in more detail and it estimates the possibility of their occurrence. Finally, it provides advice on how to prevent them and how to respond if any of them occurs. This paper thoroughly investigates LOMA development as well as its integral methodologies and validates it by outlining its performance in test cases that were performed by experts during the operation of a real landfill as well as in test cases extracted from a specially constructed database with synthetic events. (C) 2008 Elsevier Ltd. All rights reserved.