A system, method, and service associated with a computing grid or a virtual organization include a request for proposal (RFP) generator, where the RFP describes a data processing task. The RFP is provided to multiple resource providers via the computing grid where each of the resource providers is potentially suitable for performing the data processing task on behalf of the resource consumer. An RFP response processor receives and evaluates RFP responses generated by one or more of the resource providers. An exception processor accessible to the RFP response processor evaluates any exception in the RFP to determine if the exception disqualifies the RFP response. The exceptions may include, for example, job time limit exceptions, resource requirement exceptions, hardware/software platform requirement exceptions and others. Exception rules may be defined to guide the evaluation of the exception.