Remanufacture offers significant economic and ecological advantages over other end-of-life options. There exists a need for integrating remanufacturing considerations with traditional design assessments in order to make better tradeoffs between complex sets of design objectives. In this context, the evaluation of life cycle cost for systems undergoing remanufacture is the objective of this thesis.

A novel repairable-system reliability model that allows system modifications is developed to describe systems undergoing remanufacture. Explicit expressions of the relationships between remanufacture and life cycle cost are obtained based on the indices of the reliability model. The stochastic behavior of the reliability model is investigated to facilitate life-cycle cost estimation. It is proven theoretically that the replacement process with system modifications reaches steady state, behaving like a Homogeneous Poisson Process with a constant hazard rate. Explicit expressions for the reliability indices at steady state are obtained.

Computer simulation is proposed in this thesis as a tool to predict the replacement-process settling time early at the design stage in order to investigate the relationship between this settling time and factors that affect it, i.e., the failure density function and the repair policy. An approximate representation of the settling time function is obtained by non-linear regression analysis. The reliability model is modified to accommodate population size changes in the replacement process. The effects of two types of disturbances, pulse or continuous, on the replacement rate behavior are studied. A real-life example is presented for analysis of part population replacement process under continuous disturbance. It is noted that, although a simulation using the reliability model proposed in this thesis may not yield the exact replacement rate at one specific time, the error bound on this estimation is acceptable.

Conclusions of this work and recommendations for future work are discussed at the end of the thesis.