1. A method for managing a plurality of computing machines, the method comprising: deploying an indication of a management activity having an applicability rule to selected one or more of the computing machines to cause each of the selected computing machines fulfilling the applicability rule to execute the management activity on the selected computing machine, the management activity being executed on a selected one or more of the computing machines to make the selected one or more computing machines compliant with a policy, the applicability rule indicating whether to apply the policy to the selected one or more computing machines when the selected one or more computing machines fulfill the applicability rule, receiving an error message for each failure computing machine of the selected computing machines wherein the execution of the management activity has failed, determining at least one relevant property of each failure computing machine among a plurality of selected properties of the computing machines according to the corresponding error message, collecting a value of the at least one relevant property of each failure computing machine among the selected properties of the computing machines, the value of the at least one relevant property of each failure computing machine among the selected properties of the computing machines comprising a failure value of each relevant property for each failure computing machine, and updating the applicability rule according to the failure values; and wherein the values of the selected properties comprise a success value of each relevant property for each success computing machine wherein the application of the policy has succeeded, said updating the applicability rule comprising, for each relevant property: restricting the applicability rule according to the failure values in view of the success values of the relevant property, said updating the applicability rule comprises, for each relevant property: determining a failure context according to a consolidation of the failure values of the relevant property, verifying a property conflict between the success values of the relevant property and the failure context, and restricting the applicability rule according to the failure context in response to an absence of the property conflict.