We propose two alternatives for recovering from the impossibility to handle correct behaviour.
An alternative for the critique step is to better tune the Obs-mapping component to the Vocabulary component initial-fault-nodes. In general, the combination of abd-mapping and initial-fault-nodes is not an obvious choice, because using the initial-fault-nodes assumes that only abnormal behaviour is observed. However, the given problem contains also normal behaviour light(yes).
A more obvious choice of Obs-mapping component can be determined by checking whether we have observed both normal and abnormal behaviour. This is a case specific repair action, because we use the current observed behaviour in the choice of Obs-mapping. The abnormality or normality of the observed behaviour is checked using the abnormality-mapping Obsmap component. If execution of abnormality-mapping results in a non-empty set of then we use the knowledge that the combination of initial-fault-nodes and abd-mapping is a bad combination, and abnormality-mapping is probably a better one.
The previous critique step results in the same method as the `` Modify'' step, namely term (11).
The other alternative for `` Critique & Modify'' is to adapt the Vocabulary component. If the Obs-mapping component abnormality-mapping does not result in an empty set, then a better choice of Vocabulary is possibly all-initial-nodes. This vocabulary contains all initial causes (including correct states) and the incompleteness assumptions, and is therefore better tuned to Obs-mapping=abd-mapping .
We would now come to another method then before, namely:
The knowledge verification still satisfies, as before.
Performing diagnosis results in the following diagnosis part
This yields 3 x 5 = 15 diagnoses, so we have too many possible diagnoses. We end up with these other diagnoses because the critique and modify steps are based on the observation that the vocabulary was too small, whereas before the devision of the observations was considered as wrong. After verification we establish that ``too many solutions'' are computed. A repair action for solving ``too many diagnoses'' is needed. We do not describe this trace further.