Table 5 Triangular fuzzy number (TFN) (Zadeh 1978; Wang et al. 2006)

\(0\)

\(X < a\)

\(a\) has the lowest potential value of number of fuzzy number

\(\mu {\text{\ n }}_{\left( A \right)}^{\left( X \right)}\)

\(\frac{X - a}{{b - a}}\)

\(a \le X \le b\)

\(b\) has the higher potential value of number of fuzzy number

\(\frac{c - X}{{c - b}}\)

\(b \le X \le c\)

\(c\) has the highest potential value of number of fuzzy number

\(0\)

\(X > c\)

\(c\) has the highest potential value of number of fuzzy number