To develop a next-generation manufacturing system with flexibility, it is necessary to define H/W and S/W architecture based on an open architecture concept. To satisfy the open architecture concept, in this paper, H/W is divided into three parts for hard real-time task, soft real- time task, and non-real-task. And, S/W also is divided into three layered level for application level, system level, and device level. Due to the modulization of H/W and S/W, it is easily possible to modify and/or upgrade the control system including S/W and H/W according to user requirements. Especially, it is also possible to develop a new control system by modifying a part of application and device level. To show the validity of the proposed method, a detail control concept of wire bonder with the open architecture concept is described.