Structural reliability calculations are now recognised by many as only one
part of the assessment of structural safety. They provide partial evidence
about the total problem which has to be integrated with other evidence to s
upport decision making. It is proposed that a 'holistic' systems view based
on a clear understanding of process is required. The model consists of int
eracting processes arranged in a hierarchy of differing levels of precision
of definition and scope. The various attributes of each process are outlin
ed under the generic headings of 'who, what, why, where, when and how'. The
'how' attributes of a process which are important in the control of a proc
ess are hazard and risk. It is suggested that Interval Probability Theory i
s a suitable measure of the evidence that a process is being and will be ma
naged to a successful conclusion. This can be combined with structural reli
ability predictions to give bounds on the evidence about the success of the
total process which covers all foreseeable aspects of the uncertainty. (C)
1999 Elsevier Science Ltd. All rights reserved.