
Figure 3. Effect of b on MTTFF.
Figure 4. Effect of r on MTTFF.
Figure 5. Effect of θ on MTTFF.
5 CONCLUSIONS
In this paper, the machine interference model where
there are several operating units and one repairman
was considered. The failed impatient units may balk
or renege from the queuing and the repairman takes the
single vacation. From the viewpoint of reliability the-
ory, some performance analyses are presented utilizing
the method of blocked matrix. Numerical analyses are
carried out. It can be concluded that the effect of r
on MTTFF is less insensitive than other parameters.
When the value of µ is small, MTTFF changes dras-
tically. The effect