Through-life engineering

“Mark Norris will be contributing two chapters to a forthcoming book on through-life engineering.


One considers Whole Life Cost Modelling.


With the release of the new Asset Management Standard ISO55001 on 10-Jan-14, replacing PAS55, there is a growing interest in methods to assess and control Through-Life costs for major assets.

Whether you are considering the running costs of a power station, wind farm, water treatment plant, fleet of aircraft, trains or buses etc. the methodology, tools and techniques remain the same.

The case study presented here explores the methodology, tools and techniques used in practice to build a Whole Life Cost Model (WLCM) as a Decision Support Tool for existing and new Metro Rolling Stock for London Underground. The purpose of the WLCM was to understand the cost implications of extending the life of both the existing and new rolling stock designed to deliver a 40 year life, to 60 or 65 years, i.e. at what point, and under what circumstances, would refreshment, refurbishment or replacement be most cost effective? In this way the WLCM was used to explore the impact of varying rates of both performance and reliability degradation.

The different stages from the critical requirements stage – if this is incorrect subsequent effort is in vain – through breaking down the asset into cost centres, creating and applying degradation curves, interdependent processes such as Reliability Growth Planning and Reliability Centred Maintenance – already widely used to improve performance and reduced operating costs – are explored. The author also shows how the application of Six Sigma techniques provides a better understanding of current issues, enabling improvements to future planning.”