If I understand you right, you want to check, if some value (empcode) has already assigned some value? Isn't it a simple null-check? empcode != null Please explain your problem more detailled, if this is not an answer to your question. Alexander

The question is, why can the value not be updated, and when do you expect to recognize it. Do you want to call emp.setEmpCode("manya") in the rhs of your rule? Then probably, you could model this method as to return true, if the value was changed and false otherwise. Depending on the return value of the method you can make the console output in the rhs. Of course, this is conditional code, which should be avoided in the rhs of rules, but in this case it depends on stuff, which can only be done in the rhs (set..) If you want to set the empcode somewhere else outside of Drools and you want some rules to inform you about the failing of this assignment, it is somehow more subtle. The one possibility would be, if there is an intrinsic property, which you have to find, indicating, that such an assignment will always fail. The other possibility is to add a boolean flag, which points out, if something went wrong. In the external assignment method you could set this flag appropriately and check it inside Drools. Does this answer your question? Alexander