# Tutorial 2

## 3:30 to 5:00 p.m. Wednesday April 22, 2015

### Repairable Systems: Data Analysis and Modeling

Many complex systems, such as automobiles, aircraft engines, telecommunication systems and plant equipment, are repairable. When evaluating the field operation of such systems, an analyst is often times interested in answering questions such as what is the reliability over a given time, how many failures are expected during warranty, what is the cost of maintenance and what is the optimum time to preventively maintain the system.

This tutorial will provide an overview of two analysis methods that can answer such questions. First, a common mistake in the analysis of repairable systems will be discussed. Then, through an example, the correct modeling of repairable systems will be introduced using two methodologies: the Non-Homogeneous Poisson Process (NHPP) and Reliability Block Diagrams (RBDs) with simulation. The metrics that can be calculated and the advantages and disadvantages of each methodology will be discussed.

**Key Words:** RBDs, NHPP, Repairable Systems Analysis

Athanasios Gerokostopoulos

ReliaSoft Corporation

USA