Most phenomena in nature, society and technology are subject to random variation. This randomness is often ignored when considering such phenomena; what tends to be concentrated on instead is the average trends, in order to interpret the nature of a relationship being investigated. Quite often, however, it is not the mean value, but an extreme value that deter mines the performance of a system. In the past this has generally been taken into account in technology by multiplying known mean values by 'safety factors'. This is the method used, for example, to match the mechanical strength of extremely varied structures to anticipated static and dynamic stresses. We need a rather better approach to the problems outlined, both for a more precise description of the phenomena themselves and also for the economical use of raw materials and energy. The deterministic description of average trends needs to be replaced by a thorough statistical treatment of stochastic/random phenomena - right down to the construc tional design of technical structures. This task is far easier to set than to solve, however. It often encounters experimental problems in the specialist field concerned and also major difficulties of mathematical formulation. No complete solution to the problem can therefore be expected in any technical field: what one must always aim at is rather to arrive at technically effective partial solutions, through close collaboration between technical specialists and mathematicians.

Inspec keywords: high-voltage engineering; statistical analysis; power engineering

Other keywords: statistical techniques; high voltage engineering; extreme value

Subjects: Power systems; Probability and statistics