AbstractIn Part I, a Complex System consisting ofncomponents having a wide class of inter-failure time distributions and general repair time distributions with probability densitiesS1(x),S2(x), ..,Sn(x) is examined with regard to Dependability. Some particular results are derived at the end of this part. The well-known phase and supplementary-variable techniques are employed for the solution. Part II considers the possibility of the inclusion of waiting time distribution for a failed system while examining its behaviour with regard to dependability. The Laplace transforms of various probabilities that the system is operable, waiting for repair and under repair are obtained. Some particular cases are then discussed in some detail.