A combinatorial search method implemented in a computer control system utilizes on-line state-space planning of operations for multi-step production processes. The planner considers various possible combinations of actions, searching for one that correctly transforms the initial state of the object into the specified desired final state. Each combination of actions the planner considers is called a search node, with each node containing a plan representing a series of actions of various machines on a single object and also containing the predicted state of the object with those actions applied either forward or backward. The method includes determining which of the search nodes to extend further at each search iteration and if the object state in the chosen search node conforms to the desired state of the object, or whether actions should be added to the node's plan. Actions that are applicable to the chosen node's object state are selected, transformations are applied to the attributes, and the resulting plan is returned to the system.