Quality function deployment based on simultaneous equations model

Quality function deployment can be regarded as a multi-input and multi-output system. The concept of extended house of quality is proposed based on the ASI model. With respect to the relationships of the WHATs, simultaneous equations model is first put forward to establish the house of quality. In the structural equations of simultaneous equations model, the coefficients of the endogenous variables represent the correlation matrix of the customer requirements, while the coefficients of the exogenous variables denote the relationship matrix between the customer requirements and engineering characteristics. All the coefficients can be easily determined by two stage least squares estimation of the simultaneous equations model. The structural simultaneous equations model is suitable to represent the structure of the house of quality. At last, a numeric example is used to illustrate the validity of the model.