1. A virtual production control system (VPCS), comprising: a data pre-processing module used for processing a current shipping plan and a plurality of sets of historical WIP (Work-In-Process) data respectively belonging to a plurality of historical production cycles sent from a supplier side, thereby obtaining a plurality of historical input schedules and a plurality of historical output schedules belonging to said historical production cycles; a WIP monitoring module used for performing an integer programming (IP) by using said current shipping plan and one of said historical input schedules belonging to the most recent one of said historical production cycles, thereby computing a latest ideal input schedule and a latest ideal output schedule belonging to a next production cycle following said historical production cycles; and a production conjecture module used for simulating and obtaining a latest feasible input schedule and a latest feasible output schedule belonging to said next production cycle by using said historical input schedules, said historical output schedules, and said latest ideal output schedule belonging to said next production cycle in accordance with a distributed-parameters estimation method, a neural network method algorithm and Petri Nets (PN).