This thesis focuses on the use of computer simulation for modeling risk of a multi-state repairable component.

In production processes, maintenance decisions are often made based on uncertain assessment of risk, not only in the probability when a process component goes into a state of failure but also in the cost of lost production and preventive maintenance. In this thesis work, preventive maintenance of a component is modeled and simulated, in order to minimize risk (cost), as:​

• a Markov process with multiple states and fixed transition probabilities, under the assumption that with a sufficient number of states the Markovian property is valid,
• a non Markov process with two possible states and non-fixed transition probabilities for a periodically decreasing reliability component, and
• a non Markov process with two possible states and non-fixed transition probabilities for a continuously decreasing reliability component.