In this paper, a novel methodology for the Integrated Design (ID) of processes with linear Model Predictive Control (MPC) is addressed, providing simultaneously the dimensions of the plant, the control system parameters and a steady state working point. The MPC chosen operates over infinite horizon in order to guarantee stability and it is implemented with a terminal penalty. The ID methodology considers norm based indexes for controllability, as well as robust performance and stability conditions by using a multi-model approach. Mathematically, the ID is stated as a multi-objective nonlinear constrained optimization problem. Particularly, objective functions include investment, operating costs, and dynamical indexes based on the weighted sum of some norms of different closed loop transfer functions of the system. The paper illustrates the application of the proposed methodology for the ID of the activated sludge process of a wastewater treatment plant (WWTP).