There are three types of measures for handling of vague
parametric-information: possibility, necessity, and credibility.
Zadeh (1978) proposed the concept of possibility measure to indicate
how much one can believe a fuzzy event would occur. The concept
has been widely used in solving fuzzy problems. As a dual part of
possibility measure, the concept of necessity measure can also be
used to address fuzzy problems. Since both of the measures are not
self-dual, Liu and Liu (2002) present the concept of credibility measure
by combining possibility and necessity measures. It has been
proven to be a more reasonable indicator measuring fuzzy events
than possibility and necessity because it can make up their disadvantages.
Therefore, credibility measure is selected in this modeling formulation
instead of possibility and necessity. Therefore, an FCCP
problem is formulated to deal with those coefficients and parameters
represented as fuzzy sets. Through the concept of credibility, the
chance of a fuzzy event that will occur can be quantified (Zhao and
Liu, 2005). The problem is shown as follows