The development of the Toyota Production System (TPS) based on principles of lean technology has especially impressed numerous manufacturers around the world. It attaches remarkable importance to reducing and then eliminating waste and focusing on added-value activities. Lean technology is growing in important and scope because they help companies become more competitive and streamlined at a time when competitive and cost reduction pressures have intensified. Accordingly, a studied furniture company intends to transform its shop floor first to lean system. It is really an interesting and practical case study, so this paper presents an implementation of lean technology in an in-plant manufacturing system through a systematic way, step by step. It could be considered as a reference of an implementation of the lean technology.