In this research, cellular manufacturing layout design based on Systematic Layout Planning (SLP) and selection of facilities layout design by Analytic Hierarchy Process (AHP) are applied to a case study of an Electronic Manufacturing Service (EMS) plant. Currently layout of this manufacturing plant is a process layout, which is not suitable due to the nature of an EMS that has high-volume and high-variety environment. Moreover, quick response and high flexibility are also needed. Then, cellular manufacturing layout design was determined for the selected group of products. SLP was used to analyzed and designed possible cellular layouts for the factory. In order to evaluate the best alternative layout, criteria for plant selection were determined. These performance measures were weighted by AHP. Then, the best cellular layout design was selected. This case study has shown the practical guideline for design and selection of the best EMS layout.