spinjala wrote Let's walk through the code. Solver.solve() will look for solutions until any of the conditions specified by the termination configuration are met. These could be based on time, or score, etc. In your case, your best solution will have a negative hard score. You would find this via: Solution Sol = solver.getBestSolution(); if (Sol.getScore().getHardScore() == 0) { // no constraints are violated } else { // Sol = null } spinjala wrote Sharpen your grammar here. Your first sentence's first clause says that the feasible solution is not generated, but the last clause references "the generated one." So who (or what) is making this custom solution? Remember that the Solution is your class. You are free to write your own code to fill it on your own via your own code (or user actions). Jon -- View this message in context: http://drools.46999.n3.nabble.com/modifying-the-problem-facts-while-runni... Sent from the Drools: User forum mailing list archive at Nabble.com.