bexpr=Or@@And@@@MapIndexed[#1[[;;First[#2]]]&,Array[(Subscript[x, #1,#2])&,{5,5}]];

ℛ=ReliabilityDistribution[bexpr,Flatten[MapIndexed[#1[[;;First[#2]]]&,Array[{(Subscript[x, #1,#2]),ExponentialDistribution[1]}&,{5,5}]],1]];
BarChart[{StructuralImportance[ℛ],BarlowProschanImportance[ℛ],BirnbaumImportance[ℛ,1],CriticalityFailureImportance[ℛ,1],CriticalitySuccessImportance[ℛ,1],ImprovementImportance[ℛ,1],RiskAchievementImportance[ℛ,1],RiskReductionImportance[ℛ,1],FussellVeselyImportance[ℛ,1]},ChartLayout->"Percentile",BarOrigin->Left,Ticks->None,ChartLabels->{Placed[{StructuralImportance,BarlowProschanImportance,BirnbaumImportance,CriticalityFailureImportance,CriticalitySuccessImportance,ImprovementImportance,RiskAchievementImportance,RiskReductionImportance,FussellVeselyImportance},Left],None}]