An integrated fuzzy-based decision support system for the selection of lean tools: a case study from the steel industry

Lean manufacturing has been a topic of considerable interest in manufacturing for the past few years. It is now widely acknowledged that organizations that have mastered lean manufacturing methods have substantial advantage in terms of cost and quality over those still practising traditional mass production. Value stream mapping (VSM) provides a systematic way for the implementation of lean manufacturing philosophy. It consists of a range of mapping tools for the identification of the various types of waste occurring in different manufacturing stages. The selection of an appropriate mapping tool for the identification of waste at a macro- and microlevel in the manufacturing system is a complex decision-making problem. In this paper, a fuzzy-based multipreference, multicriterion, and multiperson decision-making heuristic has been developed to resolve the problem of such magnitude. A case study of the steel industry has been taken into account. Here, a hierarchy related to the decision problem has been developed and is resolved by a fuzzy analytical hierarchy process (AHP). The underlying issues pertaining to implementation of lean philosophy and decision-making procedures are considered, with reference to mathematically validated methods available in the literature.