In a previous work, we showed that artificial neural networks (ANNs) c
ould learn the criteria for comparing fuzzy numbers of a real decision
maker. A multilayer feed-forward ANN and the backpropagation algorith
m, and trapezoidal fuzzy numbers were considered. The criteria of thre
e people were learnt with an ANN. The trained ANN is considered as a p
ersonal method of the decision-maker to compare fuzzy utilities and it
has been applied to some decision problems. In this paper, a decision
personal index (DPI) of fuzzy numbers based on the trained ANN is dev
eloped in order to measure distance between the numbers. The DPI ranks
them with values in [0,1] interval, and we apply it to some problems
on matrix games and linear optimization with a fuzzy environment. Some
examples are also shown.