One of the most ambitious projects of the era of great expectations was the General Problem Solver (GPS).
Allen Newell and Herbert Simon from the Carnegie Mellon University developed a general-purpose program to simulate human-solving methods.Newell and Simon postulated that a problem to be solved could be defined in terms of states.They used the mean-end analysis to determine a difference between the current and desirable or goal state of the problem, and to choose and apply operators to reach the goal state.The set of operators determined the solution plan.