An integrated AHP–NLP methodology for facility layout design

A facility layout design (FLD) problem can be generally introduced as assignment of facilities (departments) to a site such that a set of criteria are satisfied or some objectives are minimized (maximized). Hence, It can be considered as a multi-criteria problem due to presence of the qualitative criteria such as flexibility and the quantitative criteria such as total cost of handling material. This paper aims to incorporate qualitative criteria in addition to quantitative criteria for evaluating facility layout patterns (FLPs). We present a decision-making methodology based on a simple nonlinear programming model (NLP) and analytic hierarchy process (AHP). A computer-aided layout-planning tool, Spiral, is adopted to generate the FLPs, as well as their quantitative data. The AHP is then applied to determine weights of qualitative criteria. An NLP model is proposed to solve the FLD such that it considers both the quantitative and qualitative data simultaneously. Finally, the proposed integrated procedure is applied to a real example.

► We model an integration of NLP and AHP for facility layout design.
► We enable the DM to incorporate the ranking of the importance of the criteria.
► Assigning the weight to each criterion by the proposed NLP.