Using field data to evaluate intrusive repair

In this paper we develop a methodology of using field data to evaluate intrusive repair. Intrusive repair is a phenomena where a repair action causes new failures to occur. Our methodology uses causal diagrams to evaluate intrusive repair. We introduce the concept of a threshold time window and define and evaluate measures for intrusive repair and diagnostic effectiveness. We conduct this study for RS/6000 clients and servers. Care is taken to include all classes of systems. The workstations evaluated, therefore, included representatives from the desktop, deskside, and rack families. For each class of machine, data is extracted from field databases. Our methodology provides a way to characterize intrusive repair and diagnostic effectiveness. This will enable us to identify improvements to make with current products and justify improved service features in future designs. In the future, an activity planned is a way to automate the evaluation process by which the field can be monitored for potential intrusive repair and diagnosability problems