Robust rolling stock in rapid transit network

This paper focuses on the railway rolling stock circulation problem in rapid transit networks, in which frequencies are high and distances are relatively short. Although the distances are not very large, service times are high due to the large number of intermediate stops required to allow proper passenger flow. The main complicating issue is the fact that the available capacity at depot stations is very low, and both capacity and rolling stock are shared between different train lines. This forces the introduction of empty train movements and rotation maneuvers, to ensure sufficient station capacity and rolling stock availability. However, these shunting operations may sometimes be difficult to perform and can easily malfunction, causing localized incidents that could propagate throughout the entire network due to cascading effects. This type of operation will be penalized with the goal of selectively avoiding them and ameliorating their high malfunction probabilities. Critic trains, defined as train services that come through stations that have a large number of passengers arriving at the platform during rush hours, are also introduced. We illustrate our model using computational experiments drawn from RENFE (the main Spanish operator of suburban passenger trains) in Madrid, Spain. The results of the model, achieved in approximately 1 min, have been received positively by RENFE planner

Integration of Timetable Planning and Rolling Stock in Rapid Transit Networks

The aim of this paper is to propose an integrated planning model to adequate the offered capacity and system frequencies to attend the increased passenger demand and traffic congestion around urban and suburban areas. The railway capacity is studied in line planning, however, these planned frequencies were obtained without accounting for rolling stock flows through the rapid transit network. In order to provide the problem more freedom to decide rolling stock flows and therefore better adjusting these flows to passenger demand, a new integrated model is proposed, where frequencies are readjusted. Then, the railway timetable and rolling stock assignment are also calculated, where shunting operations are taken into account. These operations may sometimes malfunction, causing localized incidents that could propagate throughout the entire network due to cascading effects. This type of operations will be penalized with the goal of selectively avoiding them and ameliorating their high malfunction probabilities. Swapping operations will also be ensured using homogeneous rolling stock material and ensuring parkings in strategic stations. We illustrate our model using computational experiments drawn from RENFE (the main Spanish operator of suburban passenger trains) in Madrid, Spain. The results show that through this integrated approach a greater robustness degree can be obtaine

Robust rolling stock under uncertain demand in rapid transit networks

This paper focuses on the railway rolling stock circulation problem in rapid transit networks where the known demand and train schedule must be met by a given fleet. In rapid transit networks the frequencies are high and distances are relatively short. Although the distances are not very large, service times are high due to the large number of intermediate stops required to allow proper passenger flow. The previous circumstances and the reduced capacity of the depot stations and that the rolling stock is shared between the different lines, force the introduction of empty trains and a careful control on shunting operation. In practice the future demand is generally unknown and the decisions must be based on uncertain forecast. We have developed a stochastic rolling stock formulation of the problem. The computational experiments were developed using a commercial line of the Madrid suburban rail network operated by RENFE (The main Spanish operator of suburban trains of passengers). Comparing the results obtained by deterministic scenarios and stochastic approach some useful conclusions may be obtained

Удосконалення методів визначення схем обігу локомотивів з урахуванням технологічних особливостей вагонопотоків

This paper focuses on new analytical solutions in the area of building locomotives’ circulation plans to handle individual applications for route transportation of freight. Such a domain has been little researched for the railway network of Ukraine, whereas the present study provides a basis for automating the planning process. The main aim is to improve the methods of determining the schemes of locomotives’ turnover in the railway network of Ukraine under the condition of an accelerated handling of individual railcar traffic and with regard to technological peculiarities. The developed mathematical model simultaneously makes it possible to determine the weight of trains on the routes they follow, to outline the circuity of locomotives with regard to deploying various series of locomotives within the network, and to regulate the system of locomotive crews’ operations in view of the existing technical and technological features of locomotive facilities and the railway infrastructure. The suggested mathematical model is processed in the study through the use of an integer genetic algorithm with its own system of coding the solution. The results have confirmed the adequacy of the developed mathematical model. The use of the suggested mathematical model on the basis of the genetic algorithm can help automate the complex process of determining the schemes of locomotives’ circulation with regard to the technological peculiarities of railcar traffic and, consequently, improve the accuracy and speed of decision-making for servicing individual applications for route transportation of freight.Предложено совершенствование методов определения схем обращения локомотивов с учетом технологических особенностей вагонопотоков. Разработана математическая модель, которая позволяет найти массу поездов на маршрутах их следования, схемы обращения локомотивов и работы бригад с учетом дислокации парка с различными сериями на полигоне сети. Для решения данной математической модели применен целочисленный генетический алгоритм с собственной схемой кодирования решенияЗапропоновано удосконалення методів визначення схем обігу локомотивів з урахуванням технологічних особливостей вагонопотоків. Розроблено математичну модель, яка дозволяє знайти масу поїздів на маршрутах їх слідування, схеми обігу локомотивів та роботи бригад з врахуванням дислокації парку з різними серіями на полігоні мережі. Для рішення даної математичної моделі застосовано цілочисельний генетичний алгоритм з власною схемою кодування рішенн

Internal Integration during Organizational Transition – A Supply Chain Perspective

Tighter internal supply chain integration has been posited to lead to several operational and performance benefits. In addition, it has also been seen to aid the elicitation of external integration. However, despite the potential benefits, achieving and maintaining tighter internal integration is a challenging task and demands considerable investments in time, money, and effort. Consequently, real, tight internal supply chain integration existing in real-life companies is rather rare than common. Although the phenomenon of internal integration has aroused large interest in the academia, a single, accepted, and generalizable definition and operationalization for the concept have been lacking. The definitions have varied from researcher to researcher which has also been visible in various ways of operationalizing the concept. In addition, the discussion concerning various employees’ skills as related to internal integration has been neglected by previous researches. On the other hand, most of the existing knowledge concerning internal integration has been gained through utilizing a quantitative research approach and methods, by studying stand-alone opinions of managers or directors, in charge of single departments across several companies. The qualitative methods and utilization of multiple perspectives have largely been neglected. Moreover, all of the previous researches can be regarded to be snapshots of their time; no longitudinal researches have been executed. The purpose of the research under scrutiny was to address both the theoretical and methodological gaps visible in the previous research literature. The research consequently aimed at answering the following research questions: How can the concept of internal integration be holistically defined, taking into account the different elements presented in previous research literature? How can (the level of) internal integration be holistically operationalized and analyzed, utilizing the new definition and taking into account the analyses models and approaches presented in previous research literature? Are the findings of the current research in line with the earlier findings or does it result in deviant and/or additional results? And, which skills are needed of different organization level employees in order to manage the internal supply chain successfully? While aiming at answering these questions, the research also aimed at answering three pragmatic research questions, directly discussing the operations of the case mill of the research: How do the case mill’s production planning, production, and warehousing and dispatch departments operate functionally and how and in which occasions and forms do they interact with one another? What is the current level (spring-autumn 2015) of internal integration existing between the case mill’s concerned departments? How does the current level of internal integration appear in the light of the mill’s future operating environment? The research was executed as a qualitative, longitudinal single case study research. A Finnish paper mill in a transformation process changing from one production mode to another acted as a case company of the research. The research studied the level of internal integration existing between case mill’s three departments – production planning, production, and warehousing and dispatch – through the opinions of three organization levels – upper level white-collars, lower lever white-collars, and blue-collars – and multiple respondents representing each of the concerned departments and employee groups, during three periods of time – in the old production mode and operating environment (2013-2014), during the mill’s transition from the old production mode to the new (2014-2015), and in the new production mode and operating environment (autumn 2015 onwards). The existing level of internal integration was researched and analyzed by utilizing a new definition and operationalization of the concept of internal integration created in the research under scrutiny, by utilizing four qualitative data collection methods – introduction discussions, a qualitative survey, consequent specifying interviews, and objective observations. The research was executed from the inside; operating within the case mill while still simultaneously maintaining a position of an external researcher. The research resulted in clear additions to the existing research literature. It provides a new, more holistic definition for the concept of internal integration. In addition, it also provides a new operationalization for the concept. Moreover, it starts the discussion of relevance of various organization level employees’ skills as related to the successful management of the internal supply chain. Moreover, by utilizing deviant and new research methods, it consequently also provides additional, new theoretical information. It, for example, emphasizes the importance of researching several departments and organization levels while aiming at analyzing the true level of internal integration as the opinions of different departments and organization levels – not to mention individuals – proved to differ. Thus utilizing a too narrow research perspective can result in faulty analyses. The deviant methods utilized in the research themselves also provide clear methodological contributions, in form of researching several departments, through the eyes of several organization levels and multiple respondents, during a longer period of time – longitudinally. Finally, from the case mill’s managerial perspective, the research provides the mill representatives with deep descriptions of the mill’s internal operations and analyses of its current and potential future level of internal integration, in addition to providing specific development suggestions.Sisäinen integraatio organisaation murrostilanteessa - Toimitusketjunäkökulma Yritysten sisäisten toimitusketjujen tiiviin integraation on esitetty johtavan useisiin toiminnallisiin ja tehokkuushyötyihin. Sen on myös nähty edesauttavan yritysten välisen ulkoisen integraation aikaansaamista. Tiiviin sisäisen integraation saavuttaminen ja ylläpito on kuitenkin haastava tehtävä, se vaatii yrityksiltä huomattavaa panostusta ajassa, rahassa ja vaivannäössä. Näin ollen, tiiviin integraation esiintyminen tosi elämän yrityksissä on ennemminkin harvinaista kuin yleistä. Vaikka sisäinen integraatio on herättänyt ilmiönä suurta kiinnostusta tiedemaailmassa, yksi yleinen, hyväksytty ja yleistettävissä oleva määritelmä sisäisen integraation käsitteelle on puuttunut, kuten myös yhtenäinen operationalisointi. Kukin tutkija on määritellyt käsitteen omalla tavallaan, erot määritelmissä ovat myös nähtävissä erilaisissa tavoissa operationalisoida ilmiötä. Sisäisessä toimitusketjussa toimivien ihmisten osaaminen sisäisen toimitusketjun toimivuuden osatekijänä ja vaikuttaja on lisäksi jäänyt tiedemaailmassa toistaiseksi vaille huomiota. Toisaalta, lähes kaikki sisäisestä integraatiosta olemassa oleva teoreettinen tieto on kerätty hyödyntämällä määrällisistä tutkimusotetta ja määrällisiä tutkimus- ja tiedonkeruumenetelmiä. Kyseiset tutkimukset ovat keskittyneet pääasiassa tutkimaan yksittäisten, eri yrityksiä edustavien, tietystä osastosta vastaavien päälliköiden tai johtajien mielipiteitä. Laadullista tutkimusotetta ja monipuolisempaa näkökulmaa asiaan on hyödynnetty vain harvoin. Lisäksi, kaikki olemassa olevat tutkimukset ovat kuvauksia sen hetkisestä tilanteesta, aiheeseen liittyvää pitkittäistutkimusta ei ole suoritettu. Tämän tutkimuksen tavoitteena oli pyrkiä täyttämään olemassa olevassa tieteellisessä kirjallisuudessa havaittuja sekä teoreettisia että metodologisia puutteita. Näin ollen tutkimus pyrki vastaamaan seuraaviin tutkimuskysymyksiin: Kuinka sisäisen integraation käsite voidaan määritellä kokonaisvaltaisemmin, ottamalla huomioon olemassa olevassa tutkimuskirjallisuudessa esitetyt sisäisen integraation osatekijät? Kuinka sisäinen integraatio (ja sen taso) voidaan kokonaisvaltaisesti operationalisoida ja analysoida, ottamalla huomioon luotu uusi määritelmä sisäiselle integraatiolle ja olemassa olevassa kirjallisuudessa esitetyt erilaiset sisäisen integraation analysointimallit? Ovatko tutkimuksen tulokset samansuuntaisia aiempien tutkimusten tulosten kanssa vai tuoko se esiin jotakin uutta ja/tai erilaista? Ja, millaista erilaista osaamista eri organisaatiotasojen henkilöstöltä vaaditaan, jotta sisäinen toimitusketju toimisi mahdollisimman hyvin? Pyrkiessään vastaamaan kyseisiin tutkimuskysymyksiin, tutkimus myös pyrki vastaamaan seuraaviin pragmaattisiin, suoraan tutkimuksen case –tehtaaseen liittyviin kysymyksiin: Miten tehtaan tuotannonsuunnittelu-, tuotanto- ja varasto ja lähetysosastot toimivat ja missä tilanteissa ja miten ne ovat vuorovaikutuksessa keskenään? Mikä on kyseisten osastojen välinen, tämän hetkinen integraation taso (kevät-syksy 2015)? Miten kyseinen taso näyttäytyy tehtaan tulevaisuuden toimintaympäristön valossa? Tutkimus toteutettiin laadullisena, yksitapauksisena pitkittäistapaustutkimuksena. Tutkimuksen kohteena toimi suomalainen, juuri tuotantosuuntaansa vaihtava paperitehdas. Tutkimus tarkasteli olemassa olevan sisäisen integraation tasoa tehtaan kolmen eri osaston välillä (tuotannonsuunnittelu, tuotanto ja varasto ja lähetys), kolmen eri organisaatiotason (ylemmät toimihenkilöt, alemmat toimihenkilöt ja työntekijät) ja useamman, kutakin osastoa ja organisaatiotasoa edustavan vastaajan mielipiteiden kautta, kolmena eri aikakautena (vanhassa tuotantosuunnassa ja toimintaympäristössä (2013-2014), murrosvaiheessa (2014-2015) ja uuden tuotantosuunnan ja toimintaympäristön mukaisessa toiminnassa (syksy 2015 eteenpäin)). Olemassa olevan sisäisen integraation tasoa tutkittiin ja analysointiin hyödyntämällä tutkimuksessa kehitettyjä uutta määritelmää ja operationalisointia sisäiselle integraatiolle, käyttäen neljää laadullista tiedonkeruumenetelmää – perehdytyskeskusteluja, laadullista kyselytutkimusta, sitä seuraavia tarkentavia haastatteluja sekä havainnointia. Tutkija toimi tutkimusta tehdessään tutkimuksen kohteena olleen tehtaan sisällä, säilyttäen kuitenkin koko ajan objektiivisen tutkijan aseman. Tutkimuksella aikaansaatiin selkeää teoreettista kontribuutiota. Tutkimuksen tuloksena syntyivät uusi, kokonaisvaltaisempi määritelmä ja operationalisointi sisäisen integraation käsitteelle. Tutkimus lisäksi aloittaa tieteellisen keskustelun henkilöstön osaamisen merkityksestä onnistuneessa sisäisen toimitusketjun johtamisessa. Tutkimus myös tuotti uutta teoreettista tietoa hyödyntämällä poikkeavia ja uusia tutkimusmenetelmiä. Tutkimus esimerkiksi painottaa useamman osaston ja eri organisaatiotason samanaikaisen tutkimisen tärkeyttä, mikäli halutaan todenmukaisia tuloksia sisäisen integraation tasosta. Tutkimus todistaa, että mielipiteet vaihtelevat organisaation eri osastojen ja tasojen, kuten myös yksittäisten yksilöiden välillä. Liian kapean fokuksen käyttäminen voi näin ollen johtaa vääriin analyyseihin. Tutkimuksessa hyväksikäytetyt, poikkeavat tutkimusmenetelmät toisaalta muodostavat metodologista kontribuutiota itsessään. Tutkimus tarkasteli useampaa osastoa, useamman organisaatiotason ja tiedonantajan kautta, pidempänä ajanjaksona – pitkittäistutkimuksena. Lopuksi, tutkimuskohteen näkökulmasta katsottuna, tutkimus antaa tehtaan edustajille syväkuvauksen tutkimuksessa tarkasteltujen kolmen osaston toiminnoista kolmena eri aikakautena, sekä analyysin kyseisten osastojen välisestä tämän hetkisestä (kevät-syksy 2015) että oletetusta tulevaisuuden sisäisen integraation tasosta ja ominaispiirteistä. Lisäksi tehtaalle annetaan yksilöityjä ja suoria kehittämisehdotuksia toimintojensa järkevöittämiseksi ja tehostamiseksi.Siirretty Doriast

Rolling Stock Rescheduling in Passenger Railways: Applications in short-term planning and in disruption management

Modern society is highly dependent on a reliable railway system for workforce mobility and easy access to the cities. However, the daily operations of a large passenger railway system are subject to unexpected disruptions such as rolling stock breakdowns or malfunctioning infrastructure. In a disrupted situation, the railway operator must adapt the timetable, rolling stock and crew to the modified conditions. This adaptation of resource allocations requires the solution of complex combinatorial problems in very short time and thus represents a major challenge for the involved dispatchers. In this thesis we develop models and solution methods for the rescheduling of the rolling stock during disruptions. The models incorporate service aspects (such as seat capacity), efficiency aspects (such as number of kilometers driven by the rolling stock), and process related aspects (such as the need for night-time relocation of rolling stock). The thesis contains applications of the developed models in three different contexts. First, we present a framework for applying the rescheduling models in the highly uncertain environment of railway disruption management, and we demonstrate the trade-off between computation time and solution quality. Second, we embed the rolling stock rescheduling models in a simulation framework to account for the dynamic passenger behavior during disruptions. This framework allows us to significantly decrease the delays experienced by passengers. Third, we apply the rescheduling models to real-life planning problems from the short-term planning department of the Netherlands Railways. The models lead to a considerable speed-up of the process and significant savings

Infrastructure Design, Signalling and Security in Railway

Railway transportation has become one of the main technological advances of our society. Since the first railway used to carry coal from a mine in Shropshire (England, 1600), a lot of efforts have been made to improve this transportation concept. One of its milestones was the invention and development of the steam locomotive, but commercial rail travels became practical two hundred years later. From these first attempts, railway infrastructures, signalling and security have evolved and become more complex than those performed in its earlier stages. This book will provide readers a comprehensive technical guide, covering these topics and presenting a brief overview of selected railway systems in the world. The objective of the book is to serve as a valuable reference for students, educators, scientists, faculty members, researchers, and engineers