Simple tasks include the loading of a single canister whereas complex tasks require the operator to analyze the availability and capacity of railroad cars in order to appropriately position and load a number of different-sized canisters. Complexity of the problem depends upon variables such as the number and size of canisters to load and the position and capacity of rail cars. Positions of the rail cars, storage bins, canisters, doors, the overhead crane, and thentially fromdicated with a number of graphical elements.
Colors aid the identification of canister sizes and rail car capacities.
The dynamic model responds to control panel interactions with animated sequences representing their outcomes. In addition to the motion of rail cars, car doors and bin doors open and close, the crane moves above the rail cars and storage bins, and the crane lowers, grasps and lifts canisters. These messages represent levels of information including notification and explanation of the error, general to specific descriptions of the subgoal procedure, as well as indicating the location and operation of the expected next step. Thousands of scenarios can be easily defined for the system by stating the position of the various elements. Each problem scenario can be automatically solved by the expert system.