Decision making in industrial settings is critical for efficient and effective manufacturing. Supplier selection and evaluation is a problem of vital importance for both enterprise managers and operations management researchers. Several approaches have been used to solve this problem, including, for example, multi-objective mathematical programming, the analytic hierarchy process (AHP), the technique for order preference by similarity to ideal situation (TOPSIS), and data envelopment analysis (DEA).

The authors underscore that these methods have limitations in solving the supplier selection problem because the decisions are usually made under uncertainty or lack of information. To overcome this obstacle, the authors suggest applying grey system theory, which has been designed to deal with situations with incomplete information. The grey system theory is similar to such methods as fuzzy sets and rough sets.

The authors present a case study that selects a supplier from four candidates based on four criteria (which include ten indicators): quality (quality management performance, sample performance, and passing rate of incoming batches), price (industry price index, reduce rate of price, and payment), delivery (accurate delivery rate and order lead time), and service (effectiveness of communication and complaint resolution rate). Several invited experts evaluate the performances of the suppliers and the weights of the indicators. AHP is used to calculate the importance weights of the indicators. Grey relation decision-making calculations are performed to select the best supplier.

The authors claim that the proposed method “is more objective and reasonable” than traditional supplier-selection methods. However, the length of the conference paper (four pages) prevents the authors from providing evidence to support this claim. Furthermore, input to the case study (indicator weights and supplier performance scores) is provided as precise values, and no explanation of the types and levels of uncertainties is given. Also, the results are not compared with those that would be achieved by traditional methods.

Readers who are interested in supplier-selection methods can find additional information on the subject [1,2].