Abstract: maintenance is the basic service that manufacturer offered for customer,how to evaluate and manage maintainer is the key to guarantee maintenance on the rails.Many qualitative indexes among the evaluation indexes of maintainer are difficult to measure.This characteristic introduces the difficulties for respondent in replying to the survey.In order to overcome the difficulty,we invite fuzzy set theory into the measurement of qualitative indexes.By applying AHP in obtaining index weight and grey situation decision theory in ranking,we get satisfied results.

Key words: maintainer, qualitative indexes, evaluation, AHP, fuzzy set theory, grey situation decision