Fig. 1.
The flowchart of the proposed method.
Table 1.
Parameter settings for maintenance operations.
| Number of maintenance operation type | Mean parameter | Variance parameter | Sample size |
|---|---|---|---|
| 1 | 33.49 | 15.07 | 132 |
| 2 | 75.35 | 64.59 | 24 |
| 3 | 17.88 | 8.33 | 187 |
| 4 | 44.45 | 23.13 | 96 |
| 5 | 97.05 | 160.39 | 12 |
| 6 | 25.29 | 10.81 | 172 |
| 7 | 129.12 | 942.91 | 4 |
| 8 | 11.21 | 8.98 | 154 |
| 9 | 58.00 | 39.06 | 53 |
Fig. 2.
Illustration of the distribution characteristics of datasets 1, 2 and 3; (a)-(c) Histograms and KDE curves for dataset 1, 2 and 3; (d) Probability plot for dataset 1.
Table 2.
Hyperparameter estimates for the natural prior distributions.
| Hyperparameter source | k̂ | r̂ | ||
|---|---|---|---|---|
| System | 3.22 | 1 | 13.06 | 1.97 |
| Maintenance operation 1 | 33.55 | 1 | 8.50 | 49.87 |
| Maintenance operation 2 | 74.62 | 1 | 4.21 | 75.17 |
| Maintenance operation 4 | 44.90 | 1 | 6.45 | 45.98 |
Table 3.
Hyperparameter settings for the non-informative priors.
| Number of maintenance operation type | k̂ | r̂ | ||
|---|---|---|---|---|
| 1 | 32.32 | 0.8 | 1.3 | 41 |
| 2 | 72.42 | 0.4 | 1.2 | 50 |
| 4 | 43.10 | 0.2 | 0.1 | 8 |
Fig. 3.
The p.d.f plots for the prior distributions: (a), (c) and (e) Informative priors for maintenance operations 1, 2 and 4, respectively; (b), (d) and (f) Non-informative priors for maintenance operations 1, 2 and 4, respectively.
Fig. 4.
Maintainability curves for four estimation methods based on the synthetic data.
Fig. 5.
Illustration for the distribution characteristics of practical data; (a)-(c) Histograms and KDE curves for system level data from PT, the three maintenance operation data from PT, and the data from OT; (d) Probability plot for OT data.
Fig. 6.
Maintainability curves for four estimation methods based on practical data.