Hidden Markov Models and their Application for Predicting Failure Events
This work addresses predictive maintenance for asset management, but it appears incremental as it combines existing methods like MMMM and POMDPs for optimization.
The paper tackles the problem of predicting asset degradation and failure events by applying Markov mixed membership models (MMMM) with tied-mixture observation distributions, resulting in advantages like regularization for sparse data, reduced computational effort, and transfer learning through shared statistical strength.
We show how Markov mixed membership models (MMMM) can be used to predict the degradation of assets. We model the degradation path of individual assets, to predict overall failure rates. Instead of a separate distribution for each hidden state, we use hierarchical mixtures of distributions in the exponential family. In our approach the observation distribution of the states is a finite mixture distribution of a small set of (simpler) distributions shared across all states. Using tied-mixture observation distributions offers several advantages. The mixtures act as a regularization for typically very sparse problems, and they reduce the computational effort for the learning algorithm since there are fewer distributions to be found. Using shared mixtures enables sharing of statistical strength between the Markov states and thus transfer learning. We determine for individual assets the trade-off between the risk of failure and extended operating hours by combining a MMMM with a partially observable Markov decision process (POMDP) to dynamically optimize the policy for when and how to maintain the asset.