Aspects of improving punctuality : from data to decision in railway maintenance

Abstract: The increasing demand for transportation and sustainability makes railways attractive. The ongoing deregulation of state-owned railways means that many new organisations are entering the railway sector. Hence, reducing railway delays is increasingly important to many stakeholders, including passengers, freight customers, train operating companies, railway infrastructure managers and society in general. Therefore, the study of punctuality and its improvement is essential. The purpose of the research presented in this thesis is to explore and describe information and requirements related to railway punctuality in order to support systematic improvements. The focus is on delay causes related to infrastructure maintenance. To fulfil the stated purpose, punctuality requirements, availability concepts, failure and delay data, as well as maintenance decisions, have been studied via theoretical and empirical approaches. Data was collected through interviews, document studies, archival analysis, observations and experiments. It is found that punctuality requirements and performance are currently expressed in many, hardly commensurable, ways. Hence, it is difficult to compare punctuality data from different railways. This is further complicated by the fact that delay attribution is inconsistently performed. It is also found that there is a lack of data on train traffic and infrastructure, for example, causes of delays. Although the consistency regarding ranking of decision-making criteria is rather high, the consistency of maintenance decisions is rather low. In addition, there are many interacting causes affecting punctuality, including infrastructure, timetable, rolling stock, weather and personnel. It is also found that even though unpunctuality might be explained by unavailability of some parts of the railway system, the concept of availability is not well-established and agreed upon within the railway sector. Based on the research findings, it is proposed that punctuality should be treated as the extent to which an event takes place when agreed, for example, the agreement between a passenger and a train operating company concerning the arrival of a train at a certain time. A number of availability measures for railway are also proposed, partly based on analogies to the power industry. Furthermore, the developed and applied methodologies, based on vignettes and the Analytic Hierarchy Process (AHP), are proposed to support punctuality improvements. To summarise, based on the results of this research, it is possible to improve data collection and recording, select suitable indicators and increase the awareness of the grounds on which decisions are made, all of which contribute to improved punctuality.