Picture of athlete cycling

Open Access research with a real impact on health...

The Strathprints institutional repository is a digital archive of University of Strathclyde's Open Access research outputs. Strathprints provides access to thousands of Open Access research papers by Strathclyde researchers, including by researchers from the Physical Activity for Health Group based within the School of Psychological Sciences & Health. Research here seeks to better understand how and why physical activity improves health, gain a better understanding of the amount, intensity, and type of physical activity needed for health benefits, and evaluate the effect of interventions to promote physical activity.

Explore open research content by Physical Activity for Health...

Generalised proportional intensities models for repairable systems

Percy, D. and Alkali, B. (2006) Generalised proportional intensities models for repairable systems. IMA Journal of Management Mathematics, 17 (2). pp. 171-185.

Full text not available in this repository. Request a copy from the Strathclyde author

Abstract

Based upon the non-homogeneous Poisson process as recommended by Ascher & Feingold (1984), we investigate suitable models for describing the inter-failure times of complex repairable systems. Specifically, we modify and develop the proportional intensities model (PIM) introduced by Cox (1972b) for this purpose. We illustrate the suitability of these models on hypothetical data taken from the first of these two books. Having identified potential benefits from this approach, we extend the PIM to introduce a new class of generalized proportional intensities models (GPIM), which allow for the inclusion of preventive maintenance (PM) and predictor variables. We discuss the properties and variations of GPIM and comment on similarities and differences between these and other proposed models for complex repairable systems. We also demonstrate the application of simple GPIM to a published data set that was collected from the petroleum industry, using the programming language Fortran and the mathematical software Mathcad. Finally, we consider how the analysis can be improved and extended for scheduling PM actions in practice.