Dr Philip Scarf

Honorary Professor

Phil is Professor of Management Mathematics at Cardiff Business School, Cardiff University. He holds visiting professorships in Industrial Engineering at the Federal University of Pernambuco, Brazil, and in Statistics at King Saud University, Riyadh, Saudi Arabia. He has wide ranging interests in the application of Statistics and Operational Research in reliability and maintenance, manufacturing informatics, autonomous systems, corrosion science, and sport. He has published 87 articles in refereed journals and graduated 20 PhD students as first supervisor.

He organizes conferences on Maintenance Modelling (https://ima.org.uk/6619/mimar2018/) and Mathematics in Sport (www.mathsportinternational.com).

He has advised the FA Premier League regarding football player rating, having developed the EA Sports Player Performance Index with Ian McHale, and has held EPSRC grants relating to development of optimum strategy in track cycling (EP/F005792/1), modelling of the training process (EP/F006136/1), Bayesian calculations in maintenance modelling (GR/L92716), and condition based maintenance of production plant (GR/L20801). He was co-investigator on the EPRSC project "HEAD: Holistic evidence and design (HEAD): sensory impacts, practical outcomes"(EP/J015709/1), and on the EU FP7 Marie Curie ITN: "SMART-E: Sustainable Manufacturing through Advanced Robotics Training – Europe" (€3.9m, 2013-17), supervising an early-stage researcher in "Mathematical modelling for a self-healing robotic cell (maintenance robot)".

Phil is co-editor-in-chief of the IMA Journal of Management Mathematics (http://imaman.oxfordjournals.org/).

Outside academia, Phil's primary hobby is sport. He is an adventure racer with Team Endurancelife and competes all over the world in expedition races. He is World Champion in Rogaining (ultra-orienteering) in the mixed-super-veterans class.

Date
Type

2025

Sahadev, S., Seiler, A. and Scarf, P. 2025. The impact of review sentiments on occupancy: Evidence for signalling theory from peer-to-peer accommodation. Journal of Vacation Marketing 31(2), pp. 351-365. (10.1177/13567667231201406)

2024

Cavalcante, C. A. V., Scarf, P., Melo, Y. R., Rodrigues, A. J. S. and Alotaibi, N. 2024. Planning maintenance when resources are limited: a study of periodic opportunistic replacement. IMA Journal of Management Mathematics 35(4), pp. 573-593., article number: dpae015. (10.1093/imaman/dpae015)
Scarf, P., Alotaibi, N., Cavalcante, C. A., Rodrigues, A. J. and Melo, Y. R. 2024. On periodic maintenance for a protection system. Proceedings of the Institution of Mechanical Engineers, Part O: Journal of Risk and Reliability (10.1177/1748006x241254420)
Scarf, P., Cavalcante, C., Alotaibi, N., Ribeiro de Melo, Y. and Rodrigues, A. 2024. Modified age-based replacement. Reliability Engineering & System Safety 245, article number: 110022. (10.1016/j.ress.2024.110022)
Scarf, P., Syntetos, A. and Teunter, R. 2024. Joint maintenance and spare-parts inventory models: a review and discussion of practical stock-keeping rules. IMA Journal of Management Mathematics 35(1), pp. 83-109. (10.1093/imaman/dpad020)

2023

Rodrigues, A. J. d. S., Cavalcante, C. A. V., Alberti, A. R., Scarf, P. and Alotaibi, N. M. 2023. Mathematical modelling of mission-abort policies: a review. IMA Journal of Management Mathematics 34(4), pp. 581-597. (10.1093/imaman/dpad005)
Alotaibi, N. M., Scarf, P., Cavalcante, C. A. V., Lopes, R., de Oliveira e Silva, A. L., Rodrigues, A. J. S. and Alyami, S. A. 2023. Modified-opportunistic inspection and the case of remote, groundwater well-heads. Reliability Engineering & System Safety 237, article number: 109389. (10.1016/j.ress.2023.109389)
Melo, Y. R., Cavalcante, C. A. V., Scarf, P. and Lopes, R. S. 2023. A hybrid maintenance policy with fixed periodic structure and opportunistic replacement. Proceedings of the Institution of Mechanical Engineers, Part O: Journal of Risk and Reliability 237(3), pp. 579-591. (10.1177/1748006X221100365)

2022

Singh, A., Scarf, P. and Baker, R. 2022. A unified theory for bivariate scores in possessive ball-sports: the case of handball. European Journal of Operational Research 304(3), pp. 1099-1112. (10.1016/j.ejor.2022.05.010)
van Rooij, F., Scarf, P. and Do, P. V. 2022. Planning the restoration of membranes in RO desalination using a digital twin. Desalination 519, article number: 115214. (10.1016/j.desal.2021.115214)
Scarf, P., Khare, A. and Alotaibi, N. 2022. On skill and chance in sport. IMA Journal of Management Mathematics 33(1), pp. 53-73. (10.1093/imaman/dpab026)
Baker, R., Chadwick, S., Parma, R. and Scarf, P. 2022. The binomial-match, outcome uncertainty, and the case of netball. Journal of the Operational Research Society 73(8), pp. 1856-1872. (10.1080/01605682.2021.1931496)

2021

Baker, R. and Scarf, P. 2021. Modifying Bradley-Terry and other ranking models to allow ties. IMA Journal of Management Mathematics 32(4), pp. 451-463. (10.1093/imaman/dpaa027)
Cavalcante, C. A., Lopes, R. S. and Scarf, P. A. 2021. Inspection and replacement policy with a fixed periodic schedule. Reliability Engineering and System Safety 208, article number: 107402. (10.1016/j.ress.2020.107402)

2020

Alotaibi, N. M., Cavalcante, C. A. V., Lopes, R. S. and Scarf, P. A. 2020. Preventive replacement with defaulting. IMA Journal of Management Mathematics 31(4), pp. 491-504. (10.1093/imaman/dpaa002)
Seiler, A., Papanagnou, C. and Scarf, P. 2020. On the relationship between financial performance and position of businesses in supply chain networks. International Journal of Production Economics 227, article number: 107690. (10.1016/j.ijpe.2020.107690)
de Jonge, B. and Scarf, P. A. 2020. A review on maintenance optimization. European Journal of Operational Research 285(3), pp. 805-824. (10.1016/j.ejor.2019.09.047)
Ryan, W. G., Fenton, A., Ahmed, W. and Scarf, P. 2020. Recognizing events 4.0: the digital maturity of events. International Journal of Event and Festival Management 11(1), pp. 47-68. (10.1108/IJEFM-12-2019-0060)

2019

Scarf, P., Cavalcante, C. and Lopes, R. 2019. Delay-time modelling of a critical system subject to random inspections. European Journal of Operational Research 278(3), pp. 772-782. (10.1016/j.ejor.2019.04.042)
Nafisah, I., Shrahili, M., Alotaibi, N. and Scarf, P. 2019. Virtual series-system models of imperfect repair. Reliability Engineering and System Safety 188, pp. 604-613. (10.1016/j.ress.2019.03.046)
Cavalcante, C. A. V., Scarf, P. A. and Berrade, M. D. 2019. Imperfect inspection of a system with unrevealed failure and an unrevealed defective state. IEEE Transactions on Reliability 68(2), pp. 754-775. (10.1109/TR.2019.2897048)
Scarf, P., Parma, R. and McHale, I. 2019. On outcome uncertainty and scoring rates in sport: the case of international rugby union. European Journal of Operational Research 273(2), pp. 721-730. (10.1016/j.ejor.2018.08.021)
Do, P., Assaf, R., Scarf, P. and Iung, B. 2019. Modelling and application of condition-based maintenance for a two-component system with stochastic and economic dependencies. Reliability Engineering and System Safety 182, pp. 86-97. (10.1016/j.ress.2018.10.007)

2018

Alberti, A. R., Cavalcante, C. A., Scarf, P. and Silva, A. L. 2018. Modelling inspection and replacement quality for a protection system. Reliability Engineering and System Safety 176, pp. 145-153. (10.1016/j.ress.2018.04.002)
Assaf, R., Do, P., Nefti-Meziani, S. and Scarf, P. 2018. Wear rate–state interactions within a multi-component system: a study of a gearbox-accelerated life testing platform. Proceedings of the Institution of Mechanical Engineers, Part O: Journal of Risk and Reliability 232(4), pp. 425-434. (10.1177/1748006X18764061)
Zahedi-Hosseini, F., Scarf, P. and Syntetos, A. 2018. Joint maintenance-inventory optimisation of parallel production systems. Journal of Manufacturing Systems 48(Part A), pp. 73-86. (10.1016/j.jmsy.2018.06.002)
Berrade, M. D., Scarf, P. A. and Cavalcante, C. A. V. 2018. Conditional inspection and maintenance of a system with two interacting components. European Journal of Operational Research 268(2), pp. 533-544. (10.1016/j.ejor.2018.01.042)
Cavalcante, C. A. V., Lopes, R. S. and Scarf, P. A. 2018. A general inspection and opportunistic replacement policy for one-component systems of variable quality. European Journal of Operational Research 266(3), pp. 911-919. (10.1016/j.ejor.2017.10.032)
Hosseini, F. Z., Syntetos, A. A. and Scarf, P. A. 2018. Optimisation of inspection policy for multi-line production systems. European Journal of Industrial Engineering 12(2), pp. 233-251. (10.1504/EJIE.2018.090616)

2017

Berrade, M. D., Scarf, P. A. and Cavalcante, C. A. V. 2017. A study of postponed replacement in a delay time model. Reliability Engineering and System Safety 168, pp. 70-79. (10.1016/j.ress.2017.04.006)
Akhtar, S., Scarf, P. and Rasool, Z. 2017. Rating players in test match cricket. Journal of the Operational Research Society 66(4), pp. 684-695. (10.1057/jors.2014.30)
Zahedi-Hosseini, F., Scarf, P. and Syntetos, A. 2017. Joint optimisation of inspection maintenance and spare parts provisioning: a comparative study of inventory policies using simulation and survey data. Reliability Engineering & System Safety 168, pp. 306-316. (10.1016/j.ress.2017.03.007)
Wu, S. and Scarf, P. 2017. Two new stochastic models of the failure process of a series system. European Journal of Operational Research 257(3), pp. 763-772. (10.1016/j.ejor.2016.07.052)

2016

Assaf, R., Do, P., Scarf, P. and Nefti-Meziani, S. 2016. Wear rate-state interaction modelling for a multi-component system: Models and an experimental platform. Presented at: 3rd IFAC Workshop on Advanced Maintenance Engineering, Services and Technology (AMEST 2016), Biarritz, France, 19-21 October 2016, Vol. 49. Vol. 28. pp. 232-237., (10.1016/j.ifacol.2016.11.040)
Moffatt, J. L. and Scarf, P. 2016. Sequential regression measurement error models with application. Statistical Modelling 16(6), pp. 454-476. (10.1177/1471082X16663065)
Reed, R., Scarf, P., Jobson, S. A. and Passfield, L. 2016. Determining optimal cadence for an individual road cyclist from field data. European Journal of Sport Science 16(8), pp. 903-911. (10.1080/17461391.2016.1146336)

2015

Do, P., Scarf, P. and Lung, B. 2015. Condition-based maintenance for a two-component system with dependencies. Presented at: 9th IFAC Symposium on Fault Detection, Supervision and Safety for Technical Processes (SAFEPROCESS 2015), Paris, France, 2-4 September 2015, Vol. 48. Vol. 21. pp. 946-951., (10.1016/j.ifacol.2015.09.648)
Wu, S. and Scarf, P. 2015. Decline and repair, and covariate effects. European Journal of Operational Research 244(1), pp. 219-226. (10.1016/j.ejor.2015.01.041)
Berrade, M. D., Scarf, P. A. and Cavalcante, C. A. V. 2015. Some insights into the effect of maintenance quality for a protection system. IEEE Transactions on Reliability 64(2), pp. 661-672. (10.1109/TR.2015.2417431)

2014

Moffatt, J., Scarf, P., Passfield, L., McHale, I. G. and Zhang, K. 2014. To lead or not to lead: analysis of the sprint in track cycling. Journal of Quantitative Analysis in Sports 10(2), pp. 161-172. (10.1515/jqas-2013-0112)

Industry 4.0 is connected, reconfigurable, and automated. Maintenance must become the same, not least because maintenance costs typically account for 15-60% of the total value of services. Therefore, maintenance must be dynamically planned, it must respond in real time to signals about system state, and it must be able to handle the interactions that exist between sub-systems, and between agents in the maintenance supply chain. In short, maintenance must move towards its automation.

There exist significant challenges for the automation of maintenance. Engineered objects are complex and characterised by structural, economic and wear-related dependencies between sub-systems and components. Thus, both the state and actions taken to improve the state of one component affects other components in the system, and the mathematical models that adequately describe these interactions and the data required to test relevant models are lacking. Furthermore, algorithms for automating decision-making for complex systems that integrates system prognosis with maintenance planning and execution must be developed. Conceptually, such algorithms will form the basis of a maintenance "robot" that will plan maintenance interventions dynamically, just-in-time, and with minimum human intervention. Then, one can then imagine a self-healing system: a system possessing its own maintenance robot that plans replacement, repair and routine maintenance and adjustment, considers operational demand within the planning process, orders and obtains spare parts and tools, and directs maintenance interventions that are safe, economically justified, 'just-in-time' and 'just enough' to ensure continuity of operation.

My research is focused on solving this "maintenance automation" problem, through collaborations with colleagues at Cardiff University (on joint modelling of spare-parts inventory and maintenance planning), at Federal University of Pernambuco, Brazil (on learning-algorithms for decision-making for maintenance planning), at University of Lorraine, France (on mathematical modelling of interacting wear processes in multi-component systems), and at IDE-Americas, California (on membrane replacement and renovation in reverse-osmosis desalination).

Currently, collaboratively, we have developed a digital twin (DT) of a reverse-osmosis (RO) desalination train, using a multivariate model of wear, calibrated using five years of daily data about the state of membranes of 14 RO trains in a state-of-the-art plant. This DT is being used to plan maintenance interventions in RO trains (cleaning, replacement of membranes). The next steps are to refine the multivariate wear-model, to use the DT as an environment in which to train learning-algorithms, so that maintenance planning (membrane replacement at least) can be automated in the plant and at similar plant worldwide, and to integrate inventory planning with maintenance automation, so that spare-parts ordering can be automated.

Qualifications

Ph.D. (Manchester), 'Statistical Models in Metallic Corrosion', NRC sponsored,1989
B.Sc. (Sheffield), First Class Honours in 'Probability and Statistics', 1984 (final year prize)

Editorial work

Co-Editor-in-Chief, IMA Journal of Management Mathematics, 2009→
Editorial Board member, Reliability Engineering and System Safety, 2013→
Associate Editor, Proceedings of the Institution of Mechanical Engineers, Part O: Journal of Risk and Reliability, 2016-2019
Associate Editor, Journal of Quantitative Analysis in Sports (an American Statistical Society journal), 2014-17

Conferences organised

Chair at 4th (2001), 5th (2004), 6th (2007), 7th (2011), 8th (2014), 9th (2016), 10th (2018) IMA conferences on "Modelling in Industrial Maintenance and Reliability".
Chair at 1st (2007), 2nd (2009), 3rd (2011), 4th (2013), 5th (2015), 6th (2017) "Mathematics in Sport" conferences.
Member of local organising committee for RSS 2004 conference.
Co-organiser of 11th EURO Summer Institute on "OR Models in Maintenance", 1995

Memberships

Institute for Mathematics and its Application (Fellow)
Operational Research Society
Royal Statistical Society (Fellow)
Mathsport International (Chair and founding member)
EURO Working Group on OR in Sports (founding member)

Contact Details

ScarfP@cardiff.ac.uk