An integrated approach for supplier selection and purchasing decisions

Purpose - The paper seeks to provide academic researchers and practitioners with a better understanding about purchasing strategies through an integrated approach to supplier selection and purchasing decisions. Design/methodology/approach - This paper views supplier selection as a multi-criteria problem. Through the analytical hierarchy process (AHP), in consideration of both quantitative and qualitative criteria, a set of candidate suppliers is identified. A multi-objective linear programming (MOLP) model, with multiple objectives and a set of system constraints, is then formulated and solved to allocate the optimum order quantities to the candidate suppliers. Findings - The paper provides tradeoffs among different objectives, which are more consistent with the complexity and nature of the real-world decision-making environment. It also offers better information and solutions supporting effective purchasing decisions. Research limitations/implications - The main concept of the proposed approach can be applicable to any organization with a purchasing function. However, its implementation will be very specific to a particular organization of interest, as each individual organization must define its own subjective criteria and constraints. The area of decision support system development, which automates (or computerizes) the input process of the proposed models and integrates with other databases in a company, will provide great opportunities for future research. Practical implications - The paper provides practitioners with flexibility and effectiveness in their supplier selection and purchasing decision process and with a better understanding about their future purchasing strategies. The results from the application of the proposed models to the supplier selection problem at a high-technology firm in Taiwan show that the models are effective and applicable. Originality/value - This paper takes an integrated approach to problem analysis (i.e. multi-objectives with both quantitative and qualitative information), uses a sound scientific methodology in model development (i.e. integrating AHP with MOLP), and provides practical use of the models. it offers additional knowledge and value to both academics and practitioners.