The DEMATEL method is based on graph theory that enables us
to project and solve problems visually, and it can divide multiple
factors into cause group and effect group in order to better capture
causal relationships visibly, as well as convert the relationship
between critical factors into an intelligible structural model of the
system. However, in many cases, the judgments of decision-making
are often given as crisp values, but crisp values are an inadequate
reflection of the vagueness in the real world. The fact that human
judgment about preferences are often unclear and hard to estimate
by exact numerical values has created the need for fuzzy set theory
when handling problems characterized by vagueness and imprecision.
A more sensible approach is to use, instead of numerical
values, linguistic assessments in which all assessments of criteria
in the problem are evaluated by means of linguistic variables.
Hence, there is a need to extend the DEMATEL method with fuzzy
set theory and linguistic variables for decision-making in fuzzy
environments.