Understanding the current manufacturing setup and accurately predicting the performance of a system over time makes modeling and simulation an ideal tool for systems' planning. This case study aims mainly at exploring the application of modeling and simulation (M&S) in order to evaluate and provide performance results that could help measure the capacity and the capability of an existing mattress production line, and to further investigate whether the production line could cope with the firm's expansion plan over the next five years. The simulation model was built and analyzed using the ProModel discrete-event simulation software. The analysis found that the current production setup could not cope with the demand over the next five years. Therefore, potential improvements within the production line were identified and implemented in an improved scenario model. The results indicated that the new system was able to meet the new demand and cope with the proposed expansion plan.