This paper employs multiattribute value assessment and risk analysis t
o evaluate the benefits of four alternatives to improve electrical sys
tem reliability in British Columbia. A multiattribute value model is c
onstructed as a cost-equivalent function, based on value judgments pro
vided by a group of senior system planners and two senior vice preside
nts from BC Hydro. Using data drawn from the utility's service records
and probabilities elicited from the utility's technical specialists,
a risk analysis is developed to estimate the magnitude and duration of
outages associated with the various alternatives. The value model and
probabilities are combined to estimate the expected equivalent costs
of outages over time, for the four alternatives. The influence of this
analysis on BC Hydro's transmission system planning is also discussed
.