1. A method for a managed pressure drilling (MPD) operation, comprising: operating a MPD drilling system that comprises a rotating control device (RCD), a drilling string non-return valve (NRV), and a choke manifold; providing a first reliability model for a probability of a failure mode of the MPD operation; assessing the probability of the failure mode based on the first reliability model; devising a first well control scheme to detect the failure mode assessed based on the first reliability model; providing one or more reliability models for the probability of the failure mode of the MPD operation; assessing the probability of the failure mode based on the one or more reliability models; devising one or more well control schemes to detect the failure mode assessed based on the corresponding one or more reliability models, comparing a result of the first well control scheme with results of the one or more well control schemes; selecting a well control scheme among the first well control scheme and the one or more well control schemes; and modifying the MPD drilling system according to the selected well control scheme, wherein the first reliability model and one or more reliability models are different, and are selected from the group consisting of a Failure Modes and Effects Analysis (FMEA), a Fault Tree Analysis (FTA), an Ishikawa diagram, a Pareto Chart, a Reliability Block Diagram (RBD), and combinations thereof.