Figure 1.
Execution process of system missions.
Figure 2.
Schematic figure of the proposed mission availability model.
Figure 3.
MC simulation procedure of mission independence.
Figure 4.
MC simulation procedure of mission dependence.
Table 1.
Simulation variables and results.
Figure 5.
Relationship among mission availability, reliability and maintainability.
(a) Scenario 1: Mission independence. The highlighted curves are the equal-availability curves with the availability values 0.35(0.1)0.95. (b) Scenario 2: Mission dependence. With exponential reliability rate 0.01(0.01)0.1 and Exponential repair rate 0.002(0.002)0.02.
Figure 6.
Mission availability trend under different reliability/Maintainability level.
(a) Mission availability trend when the system reliability is 0.4(0.1)0.9 and the cumulative repair function is Lognormal distribution with ,
. (b) Mission availability trend when the system reliability is 0.4 and the cumulative repair function is Lognormal distribution with
,
. The abscissas of the nodes between the red dotted line and curves represent the least bounded cumulative downtime when the required mission availability is 0.85 in (a) and 0.70 in (b).
Figure 7.
Determination of the no saturation interval.
The solid line is the fitted piecewise-linear models. The dashed curve is the change trend between reliability and maintainability with mission availability 0.65(0.05)0.95. The dotted line is the fitted linear models.