Rasool et al.
Table 9 . Variation of maintainability of subsystems with time
Time (hrs.)
MSSI
MSSII
MSSIII
MSSIV
MSSV
10 20 30 40 50
0.992553 0.999945 1.000000 1.000000 1.000000
0.999447 1.000000 1.000000 1.000000 1.000000
1.000000 1.000000 1.000000 1.000000 1.000000
0.628423 0.861931 0.948697 0.980937 0.992917
0.998497 0.999998 1.000000 1.000000 1.000000
In second phase, the steady state availability of stock preparation unit is evaluated for a particular set of parametric values. The impact of variation in failure and repair rates on steady state availability is explored. It is identified that steady state availability sharply declines with the 20% variation in various failure rates and shows the significant enhancement with the increment of repair rate of the subsystems.
Table 10 . Effect of Failure rates on the availability after μ i +20% variation
μ1
Base Values
μ2+20% of μ2
μ3+20% of μ3
μ4+20% of μ4
μ5+20% of μ5
0.873077
0.871927
0.86326
0.869449
0.866097
0.023
0.871524
0.870378
0.861742
0.867909
0.864569
0.024
0.869977 0.868435 0.866898
0.868835 0.867297 0.865765
0.860229 0.858722 0.857219
0.866375 0.864845 0.863322
0.863046 0.861528 0.860016
0.025 0.026
0.027
0.865367
0.864238
0.855722
0.861803
0.85851
0.028
0.863842
0.862716
0.854231
0.86029
0.857008
0.029
Table 11 . Effect of Repair rates on the availability after θ i +20% variation
θ1
Base Values
θ2+10% of θ2
θ3+10% of θ3
θ4+10% of θ4
θ5+10% of θ5
0.873295
0.87351
0.874471
0.88135
0.876559
0.49
0.873367
0.873077
0.873295
0.873295
0.873295
0.491
0.873438
0.87315
0.873367
0.873367
0.873367
0.492
0.87351
0.873222 0.874037
0.873438 0.880909 0.880983
0.873438 0.876123 0.876196
0.873438
0.493 0.494
0.873077
0.87898
0.87315
0.87411
0.879054
0.495
0.873222
0.874183
0.881057
0.87627
0.879127
0.496
In the last phase, nature inspired algorithms GA and PSO applied on objective function equation (30) to predict the availability of the stock preparation unit and estimate the best fitted parameters value. Table 12 -13 appended the optimization parameters and search space for prediction the availability.
Braz. J. Biom. ǡǤ 43 ǡǦͶ͵ʹǡʹͲʹͷǤ 15
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