In an automated system which includes a robot manipulator, a workcell, and a control system implemented on a hardware platform based on a programmable logic controller (“PLC”), a method and apparatus for performing integrated simulation that does not require the presence of both the robot manipulator and the workcell. If one component is real, the other component is simulated so as to be sufficiently responsive to responses from the real component such that the real component is unable to discern that the other component is not also real. A computing device simultaneously displays simulacra of both the components, real and simulated, and visualizations of the responses provided by each.