Techniques relate to an interactive logic diagnostic process. A diagnostic iteration loop is performed. When a critical failure does not have the diagnostic resolution that meets a predefined diagnostic resolution, potential faults related to the critical failure are isolated. When the critical failure has a diagnostic resolution that meets the predefined diagnostic resolution, the diagnostic iteration loop ends. Path focused fault test patterns are applied to the device under test in order to generate updated results of the path focused fault test patterns, such that the diagnostic resolution has been increased because a number of the potential faults related to the critical failure has decreased, and/or a size of a physical area of the potential faults related to the critical failure has decreased. The diagnostic iteration loop is returned to.