Quantification of Complexity and Coupling Indices to Validate Normal Accident Theory in Telecommunication Network Accidents

摘要

A system or organizational perspective has gained its importance in explaining rare and high impact accidents because it helps us to understand the complex nature of highly technical systems and the accident causes. Safety is a critical issue in telecommunication networks; therefore, understanding the inherent characteristics of the network in relation with accident occurrence has considerable merit for safer design and operation of a telecommunication network. This work of investigating a telecommunication network and its accidents applies an organizational accident theory, Normal Accident Theory (NAT), and determines if the telecommunication network belongs to a highly technical system in which accidents is ‘normal’ and ‘system inherent.’ NAT links the occurrence of unplanned and untoward events or accidents to interactive complexity and tightly coupled systems, but without quantifiable measures of the terms of ‘complexity’ and ‘coupling’. In this work, the complexity is calculated by measuring potential system states while the coupling is quantified by measuring two attributes, redundancy and time dependency. By applying the three defined quantities on a real telecommunication network and its actual accident history and by comparing them with those of other systems, this research places the telecommunication network as a complex and tightly coupled system.