This paper addresses system identification of a switched system in which each sub-system is expressed by a piecewise affine system. A considered system is expressed by a mixed logical dynamical system for which some design methods have been already known. For identification, in most cases, a number of sub-systems, that is, switching points are given in advance. However, it is not easy to find switching points for multi-variable systems. Therefore, in this paper, we propose a simultaneous identification technique which takes into account a number of sub-systems and parameters of them. The proposed method is applied to several examples to show its effectiveness.