On behalf of the Organising Committee of the 11th ARTS I would like to welcome all the delegates, session chairpersons and authors. I particularly welcome new delegates, delegates from mainland Europe and from other countries. At the time of the last symposium, our tenth anniversary, we looked back on the growth of the symposium and the support it had received from so many people. Not least was the support given by Mrs Ruth Campbell who, between this symposium and the last, has retired from the National Centre of Systems Reliability. The Organising Committee would hereby like to acknowledge a very special debt of gratitude, over many years, to Ruth. Our gratitude also goes to Dr A. Z. Keller of the University of Bradford, the Organising Committee Chairman at the 10th Symposium, our President for 11th ARTS and, since the beginning, a staunch supporter of the ARTS. Our thanks go to Mme A. Camino of Electricite de France for being our after-dinner speaker and to Mr A. J. Bourne for being our keynote speaker. Their speeches have been keenly anticipated. Behind the symposium, the detailed and hard work of the administrative staff of the National Centre of Systems Reliability continues even after it has ended. Our thanks go to them, particularly, and to the Universities of Liverpool, Manchester Institute of Science and Technology and Bradford for their consistent support to the symposium.

Human Factors.- The Application of Two Recently Developed Human Reliability Techniques to Cognitive Error Analysis.- Cognitive Task Analysis Techniques in the Design and Evaluation of Complex Technological Systems.- Evaluating Human Knowledge and the Knowledge Assessment Method: Reducing Risk Arising from Defective Knowledge.- Safety Assessment.- Time-Dependent Stochastic Modelling of Fire Spread in Segregated Structures.- Reliability of the Spent Fuel Identification for Flask Loading Procedure Used by COGEMA for Fuel Transport to La Hague.- Management at Risk.- Modelling.- A Developed Transient-Behaviour Method.- Reliability Growth Models and Application to a Processor.- Estimation of the Mean Number of Failures for Repairable Systems.- Dependency Modelling.- Dependency Modelling.- Common Cause Failure Analysis of a Subsea System.- Dependent Failures Analysis: DEFEND Database.- Software Reliability.- Software Impact on System Reliability.- Quantitative and Qualitative Reliability Assessment of Systems Including Software.- The Role of Static Analysis in Software Reliability Assessment.- Electrical Systems.- Time Sequential Reliability Assessment of Electrical Auxiliary Systems.- Canadian Electric Power System Reliability Assessment-Performance and Prediction.- Mechanical Reliability.- A Design Approach to Fatigue Reliability.- Some New Aspects on Component Importance Measures.- The Recent Development on the Non-destructive Inspection Reliability and its Applications in Offshore Structural Integrity Analysis.- Data Collection and Analysis.- Proportional Hazards Analysis of Electrical Component Reliability Data.- Strategies for Reliability Data Analysis.- Manufacturing/Processing.- Flexibility and Reliability of Processing Systems.- A Composite Model for Evaluating theOptimum Design, Maintenance, Condition Monitoring and Disposal for Any Equipment.- Case Studies.- Human Factors in Maintenance Work in the British Coal Industry.- Reliability Analysis of a Central Computer System Power Supply.- Late Submission.- An Expert System for Fault Diagnosis in Fibre Production.