Discussion concerning the multi-ranked deterioration forecasting model based on incomplete inspection data

The Markov chain model is widely used as a multiranked deterioration forecasting model for engineering structures. Though the model has the advantage of easy handling, it needs a strong assumption that the transition rate for a unit time is always constant (Ang & Tang 1984). However, the deterioration of a civil engineering structure invariably changes with respect to the elapsed time. The transition rate may generally depend on the prior state.