The paper describes the task of performing efficient
decision-theoretic troubleshooting of electromechanical devices.
In general, this task is NP-complete, but under fairly strict
assumptions, a greedy approach will yield an optimal sequence
of actions, as discussed in the paper. This set of assumptions
is weaker than the set proposed by Heckerman et al. (1995).
However, the printing system domain, which motivated the research
and which is described in detail in the paper, does not meet
the requirements for the greedy approach, and a heuristic method
is used. The method takes value of identification of the fault
into account and it also performs a partial two-step look-ahead
analysis. We compare the results of the heuristic method with
optimal sequences of actions, and find only minor differences
between the two.