1. A combinatorial search method implemented in a computer control system for utilizing on-line state-space planning of operations for multi-step production processes, wherein 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, wherein each combination of actions the planner considers is called a search node, with each node containing a plan representing a series of actions of a plurality of machines on a single object and also containing the predicted state of the object with those actions applied either forward or backward, wherein the state of the object consists of the set of attributes of the object, the method comprising: determining which of the current plurality of search nodes to extend further at each search iteration; determining 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, wherein actions are modeled in part as transformations of logical attributes of an object; selecting those actions that are applicable to the chosen node's object state; applying said transformations to said attributes; and returning the resulting plan to the system.