Management of Asset Fleets and Portfolios

This research addresses an increasing need in the industry to manage investments across large asset fleets and portfolios based on the associated risk and value of assets.


This aims at developing methodologies for prioritising maintenance across an asset portfolio considering budgetary constraints and other dependencies between the assets.


Specific activities


1. Bridge portfolio maintenance optimisation.


Here, we first develop a predictive maintenance plan for each failure mode considering the data available from the bridges. Next, an optimal intervention plan that combines the actions for the different faliure modes of a bridge is decided. Finally an yearly intervention plan for the different bridges in the portfolio is developed considering the investment required, the value generated by these investment and the risk to the organisation.


2. Optimal lifecycle maintenance planning for fleets. 


Large infrastructure assets commonly require high intervention costs, but the absence of an effective asset management plan can bring about a massive production loss for a company. Hence, managing these assets is considered a daunting task and is even more complicated if these assets operate collectively to produce an output. This research explores a pragmatic approach to a multi-asset intervention scheduling problem through a case study of a vessel fleet in a petrochemical plant. After the relationship between the asset configuration and the system output was defined, an optimisation model with an objective to jointly minimise cost and risk was developed. Since the calculation of risk profiles across the fleet requires complex non-linear functions, a genetic algorithm is employed to search for an optimal combination of intervention schedules. Compared to the current run-to-failure strategy, the optimal strategy results in a significant reduction in system failure risk and a substantial improvement in long-term fleet conditions while reducing the total cost. 



Project Partners

  • ExxonMobil
  • Hertfordshire County Council
  • Network Rail
  • BT


  • Petchrompo, S., Parlikad, A.K, “Review of asset management literature on multi-asset systems,” Reliability Engineering & System Safety, Volume 181, pp 181-201, 2019
  • Liang, Z., Parlikad, A.K., "Maintenance prioritisation of a bridge portfolio," Manuscript under preparation.
  • Petchrompo, S., Parlikad, A.K., “Heuristic optimisation for multi-asset intervention planning in a petrochemical plant,” In Proc. 7thInternational Conference on Through-Life Engineering Services, Cranfield, Nov 2018.