Sorry if I sound rude, but the last thing you'd have to worry about is about the software you will use to design, simulate, etc. First of all, where are you going to use the pump? Whats the required pressure and flow? Will be actuated mechanically, electrically? Electronic control? Environmental conditions of operation (temperature, pressure, inlet pressure)? Work cycle? How long is it supposed to work? Must be refurbishable? Any size and weight constraints? Fire harzard, cleanliness conditions in the working environment? Should be able to be easily replaced? Target cost? Target price? Production cycle? Technology involved in manufacturing and/or operation? I can think of a number of conditions your project would have to answer... Your question seem so simple, are you designing a pump, or you are just drawing it in pro-e? If that's the point, why don't you follow the software help and take a time to know the available tools? All the current engineering softwares have similar tools used in a similar maner. Imagine why? Because the software will not solve the problems for you. You will ave to imagine how to build the parts, assemble it, even if its only virtual.