Various embodiments for arranging data handling in a computer-implemented system comprising a plurality of existing physical entities include assigning at least one reliability rating to various said existing physical entities of the computer-implemented system; and using the assigned reliability ratings in accordance with reverse predictive failure analysis, to provide a designated cumulative reliability rating, the designated cumulative reliability rating being determined in accordance with the following equation: 1−[PAF(f+Δf, n+Δn)]=1−[PAF(f, n)+(∂PAF/∂f)*Δf+(∂PAF/∂n)*Δn], where PAF is a probability of failure of the computer-implemented system, f is a probability of failure of a physical entity, and n is a number of drives in the computer-implemented system.