This paper describes a decision support system (EtoPlan) that can handle a concurrent processing of the technological and logistic planning within a complex engineer-to-order manufacturing environment. The system is capable of dealing with uncertainty, caused by incomplete and unreliable information. These two aspects are essentially present in the higher level planning activities in the specified manufacturing environment. Some Graphical User Interfaces are presented and explained in order to show the practical use of the system. The system is developed for implementing and testing a new approach on concurrent manufacturing planning and control.