On the relationship between financial performance and position of businesses in supply chain networks (2020)
Journal Article
Seiler, A., Papanagnou, C., & Scarf, P. (2020). On the relationship between financial performance and position of businesses in supply chain networks. International Journal of Production Economics, 227, https://doi.org/10.1016/j.ijpe.2020.107690

We investigate how the network position of organisations in an extended supply chain network impacts their financial performance. The paper argues that performance measurement tools should incorporate a network (external, connectedness) perspective... Read More about On the relationship between financial performance and position of businesses in supply chain networks.

A review on maintenance optimization (2019)
Journal Article
De Jonge, B., & Scarf, P. (2020). A review on maintenance optimization. European Journal of Operational Research, 285(3), 805-824. https://doi.org/10.1016/j.ejor.2019.09.047

To this day, continuous developments of technical systems and increasing reliance on equipment have resulted in a growing importance of effective maintenance activities. During the last couple of decades, a substantial amount of research has been car... Read More about A review on maintenance optimization.

Delay-time modelling of a critical system subject to random inspections (2019)
Journal Article
Scarf, P., Cavalcante, C., & Lopes, R. (2019). Delay-time modelling of a critical system subject to random inspections. European Journal of Operational Research, 278(3), 772-782. https://doi.org/10.1016/j.ejor.2019.04.042

We model the inspection-maintenance of a critical system in which the execution of inspections is random. The models we develop are interesting because they mimic realities in which production is prioritised over maintenance, so that inspections migh... Read More about Delay-time modelling of a critical system subject to random inspections.

Virtual series-system models of imperfect repair (2019)
Journal Article
Nafisah, I., Shrahili, M., Alotaibi, N., & Scarf, P. (2019). Virtual series-system models of imperfect repair. Reliability Engineering and System Safety, 188(Aug 19), 604-613. https://doi.org/10.1016/j.ress.2019.03.046

Novel models of imperfect repair are fitted to classic reliability datasets. The models suppose that a virtual system comprises a component and a remainder in series. On failure of the component, the component is renewed, and on failure of the remain... Read More about Virtual series-system models of imperfect repair.

Modelling and application of condition-based maintenance for a two-component system with stochastic and economic dependencies (2018)
Journal Article
Do, P., Assaf, R., Scarf, P., & 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, 86-97. https://doi.org/10.1016/j.ress.2018.10.007

This paper develops a model of a condition-based maintenance policy for a two-component system with both stochastic and economic dependencies. The stochastic dependency is such that the degradation rate of each component depends not only on its own... Read More about Modelling and application of condition-based maintenance for a two-component system with stochastic and economic dependencies.

On outcome uncertainty and scoring rates in sport : the case of international rugby union (2018)
Journal Article
Scarf, P., Parma, R., & McHale, I. (2019). On outcome uncertainty and scoring rates in sport : the case of international rugby union. European Journal of Operational Research, 273(2), 721-730. https://doi.org/10.1016/j.ejor.2018.08.021

In this paper we investigate the relationship between outcome uncertainty and scoring rates in the framework of a “Poisson match”. We argue that increasing scoring rates in the hope of increasing entertainment may have a detrimental impact on the pop... Read More about On outcome uncertainty and scoring rates in sport : the case of international rugby union.

Wear rate-state interactions within a multi-component system : a study of a gearbox accelerated life testing platform (2018)
Journal Article
Assaf, R., Do, P., Nefti-Meziani, S., & 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), 425-434. https://doi.org/10.1177/1748006X18764061

The degradation process of complex multi-component systems is highly stochastic in nature. A major side effect of this complexity is that components of such systems may have unexpected reduced life and faults and failures that decrease the reliabil... Read More about Wear rate-state interactions within a multi-component system : a study of a gearbox accelerated life testing platform.

Modelling inspection and replacement quality for a protection system (2018)
Journal Article
Alberti, A., Cavalcante, C., Scarf, P., & Silva, A. (2018). Modelling inspection and replacement quality for a protection system. Reliability Engineering and System Safety, 176, 145-153. https://doi.org/10.1016/j.ress.2018.04.002

An inspection and replacement policy for a protection system is described by a mathematical model that incorporates multiple aspects of maintenance quality. A three-state component failure model is assumed, with a defective state preceding failure. T... Read More about Modelling inspection and replacement quality for a protection system.

Conditional inspection and maintenance of a system with two interacting components (2018)
Journal Article
Berrade, M., Scarf, P., & Cavalcante, C. (2018). Conditional inspection and maintenance of a system with two interacting components. European Journal of Operational Research, 268(2), 533-544. https://doi.org/10.1016/j.ejor.2018.01.042

In this paper we consider the inspection and maintenance of a two-component system with stochastic dependence. A failure of component 1 may induce the defective state in component 2 which in turn leads to its failure. A failure of component 1 and a d... Read More about Conditional inspection and maintenance of a system with two interacting components.

A general inspection and opportunistic replacement policy for one-component systems of variable quality (2017)
Journal Article
Cavalcante, C., Lopes, R., & Scarf, P. (2018). A general inspection and opportunistic replacement policy for one-component systems of variable quality. European Journal of Operational Research, 266(3), 911-919. https://doi.org/10.1016/j.ejor.2017.10.032

We model the influence of opportunities in a hybrid inspection and replacement policy. The base policy has two phases: an initial inspection phase in which the system is replaced if found defective; and a later wear-out phase that terminates with rep... Read More about A general inspection and opportunistic replacement policy for one-component systems of variable quality.

A study of postponed replacement in a delay time model (2017)
Journal Article
Berrade, M., Scarf, P., & Cavalcante, C. (2017). A study of postponed replacement in a delay time model. Reliability Engineering and System Safety, 168, 70-79. https://doi.org/10.1016/j.ress.2017.04.006

We develop a delay time model for a one component system with postponed replacement to analyze situations in which maintenance might not be executed immediately upon discovery of a defect in the system. Reasons for postponement are numerous: to avoid... Read More about A study of postponed replacement in a delay time model.

Sequential regression measurement error models with application (2016)
Journal Article
Scarf, P., & Moffatt, J. (2016). Sequential regression measurement error models with application. Statistical Modelling, 16(6), 454-476. https://doi.org/10.1177/1471082X16663065

Sequential regression approaches can be used to analyse processes in which covariates are revealed in stages. Such processes occur widely, with examples including medical intervention, sports contests, and political campaigns. The naïvenaive sequenti... Read More about Sequential regression measurement error models with application.

Two new stochastic models of the failure process of a series system (2016)
Journal Article
Wu, S., & Scarf, P. (2017). Two new stochastic models of the failure process of a series system. European Journal of Operational Research, 257(3), 763-772. https://doi.org/10.1016/j.ejor.2016.07.052

Consider a series system consisting of sockets into each of which a component is inserted: if a component fails, it is replaced with a new identical one immediately and system operation resumes. An interesting question is: how to model the failure... Read More about Two new stochastic models of the failure process of a series system.

Determining optimal cadence for an individual road cyclist from field data (2016)
Journal Article
Reed, R., Scarf, P., Jobson, S., & Passfield, L. (2016). Determining optimal cadence for an individual road cyclist from field data. European Journal of Sport Science, 16(8), 903-911. https://doi.org/10.1080/17461391.2016.1146336

The cadence that maximises power output developed at the crank by an individual cyclist is conventionally determined using a laboratory test. The purpose of this study was two-fold: (i) to show that such a cadence, which we call the optimal cadence,... Read More about Determining optimal cadence for an individual road cyclist from field data.

Some insights into the effect of maintenance quality for a protection system (2015)
Journal Article
Berrade, M., Scarf, P., & Cavalcante, C. (2015). Some insights into the effect of maintenance quality for a protection system. IEEE Transactions on Reliability, 64(2), 661-672. https://doi.org/10.1109/TR.2015.2417431

This paper considers an inspection and preventive replacement policy for a one-component protection or cold standby system. Inspection is imperfect, and subject to false positives and negatives; preventive replacement may also be of poor quality. W... Read More about Some insights into the effect of maintenance quality for a protection system.

Decline and repair and covariate effects (2015)
Journal Article
Wu, S., & Scarf, P. (2015). Decline and repair and covariate effects. European Journal of Operational Research, 244(1), 219-226. https://doi.org/10.1016/j.ejor.2015.01.041

The failure processes of repairable systems may be impacted by operational and environmental stress factors. To accommodate such factors, reliability can be modelled using a multiplicative intensity function. In the proportional intensity model, the... Read More about Decline and repair and covariate effects.

Rating players in test match cricket (2015)
Journal Article
Akhtar, S., Scarf, P., & Rasool, Z. (2015). Rating players in test match cricket. Journal of the Operational Research Society, 66, 684-695. https://doi.org/10.1057/jors.2014.30

In general, the evaluation of player performance in test cricket is based on measures such as batting and bowling averages. These measures have a number of limitations, among which is that they fail to take into account the context in which runs ar... Read More about Rating players in test match cricket.

Modelling imperfect inspection over a finite horizon (2013)
Journal Article
Berrade, M., Cavalcante, C., & Scarf, P. (2013). Modelling imperfect inspection over a finite horizon. https://doi.org/10.1016/j.ress.2012.10.003

This paper models imperfect inspection policies for a system with a finite operational time requirement. Two types of maintenance policy are considered: that in which an alarm (a positive inspection) is followed by a check of the validity of the alar... Read More about Modelling imperfect inspection over a finite horizon.

Imperfect inspection and replacement of a system with a defective state: A cost and reliability analysis (2013)
Journal Article
Berrade, M., Scarf, P., Cavalcante, C., & Dwight, R. (2013). Imperfect inspection and replacement of a system with a defective state: A cost and reliability analysis. Reliability Engineering and System Safety, 120, 80-87. https://doi.org/10.1016/j.ress.2013.02.024

We consider a system with three possible states, good, defective and failed. Failures are detected as soon as they occur; the defective state, which is only revealed by inspection, does not prevent the system from fulfilling the function for which it... Read More about Imperfect inspection and replacement of a system with a defective state: A cost and reliability analysis.

The effect of maintenance quality on spare parts inventory for a fleet of assets (2013)
Journal Article
Van Horenbeek, A., Scarf, P., Cavalcante, C., & Pintelon, L. (2013). The effect of maintenance quality on spare parts inventory for a fleet of assets. IEEE Transactions on Reliability, 62(3), 596-607. https://doi.org/10.1109/TR.2013.2270409

This paper considers the effect of fleet size on a joint policy of maintenance and spare parts inventory when spare parts are of varying quality. We consider N identical one-component systems subject to age-based replacement, and with a single echelo... Read More about The effect of maintenance quality on spare parts inventory for a fleet of assets.