Enterprise waste evaluation using the analytic hierarchy process and fuzzy set theory

Abstract

The constraints of time and cost make it impossible to eliminate all waste within a commercial enterprise, so an effective way to eliminate key sources of waste and continuously improve waste control is needed. Identifying the key sources of waste that should be eliminated is an important first step towards achieving this. In this paper a method is described that can be used to evaluate the sources of waste within an enterprise and identify the key waste sources that should be eliminated. Since fuzzy relationships exist among the different types of waste, the enterprise waste-evaluation problem can be seen as a fuzzy unstructured decision problem. To resolve it and identify the key sources of waste to eliminate, the proposed method combines the analytic hierarchy process (AHP) and fuzzy set theory and establishes a three-step procedure consisting of evaluating, clustering and ranking. First a waste-evaluation index system is established using the AHP so that the harmfulness of each type of waste can be measured systematically and the more harmful waste sources identified. Second, fuzzy clustering is used to cluster the more harmful sources of waste on the basis of their fuzzy correlation, and summarize these into key sources of waste. Last, fuzzy comprehensive evaluation is used to rank the priority of each type of key source of waste for elimination. This method enables enterprises to effectively identify and eliminate their key sources of waste. After explaining how this method can be applied, the results from a field trial conducted to test the method's effectiveness are analysed.