Strategic vehicle fleet management–a joint solution of make-or-buy, composition and replacement problems

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Adam Redmer
Keyword(s):  
Management Strategy ◽  
Large Scale ◽  
Real Life ◽  
Optimization Methods ◽  
Solution Procedure ◽  
Fleet Management ◽  
Content Type ◽  
Fleet Size ◽  
Real Life Data ◽  
Management Problems

PurposeThe purpose of this paper is to develop an original model and a solution procedure for solving jointly three main strategic fleet management problems (fleet composition, replacement and make-or-buy), taking into account interdependencies between them.Design/methodology/approachThe three main strategic fleet management problems were analyzed in detail to identify interdependencies between them, mathematically modeled in terms of integer nonlinear programing (INLP) and solved using evolutionary based method of a solver compatible with a spreadsheet.FindingsThere are no optimization methods combining the analyzed problems, but it is possible to mathematically model them jointly and solve together using a solver compatible with a spreadsheet obtaining a solution/fleet management strategy answering the questions: Keep currently exploited vehicles in a fleet or remove them? If keep, how often to replace them? If remove then when? How many perspective/new vehicles, of what types, brand new or used ones and when should be put into a fleet? The relatively large scale instance of problem (50 vehicles) was solved based on a real-life data. The obtained results occurred to be better/cheaper by 10% than the two reference solutions – random and do-nothing ones.Originality/valueThe methodology of developing optimal fleet management strategy by solving jointly three main strategic fleet management problems is proposed allowing for the reduction of the fleet exploitation costs by adjusting fleet size, types of exploited vehicles and their exploitation periods.

Valuing retail lease options through time

2017 ◽  
Vol 35 (4) ◽  
pp. 369-381 ◽  
Author(s):  
Jussi Vimpari ◽  
Seppo Junnila
Keyword(s):  
Option Pricing ◽  
Real Option ◽  
Real Life ◽  
Option Valuation ◽  
Content Type ◽  
Life Data ◽  
Property Owner ◽  
Real Life Data ◽  
Different Types ◽  
Lease Contracts

Purpose Retail properties are a perfect example of a property class where revenues determine the rent for the property owners. Estimating the value of new retail developments is challenging, as the initial revenues can have a significant variance from the long-term revenue levels. Owners and tenants try to manage this problem by introducing different kind of options, such as overage rent and extension rights, to the lease contracts. The purpose of this paper is to value these options through time for different types of retailers, using real-life data with a method that can be easily applied in practice. Design/methodology/approach This paper builds upon the existing papers on real option studies but has a strong practical focus, which has been identified as a challenge in the field. The paper presents simple mathematical equations for valuing overage rent and extension options. The equations capture the value related to uncertainty (volatility) that is missed by standard valuation practices. Findings The results indicate that overage and extension options can represent a significant proportion of retail lease contract’s value and their value is heavily time-dependent. The option values differ greatly between tenants, as the volatilities can have a large spread across tenants. The paper suggests that the applicability of option pricing theory and calculus should not be considered as an insurmountable barrier any more, rather a greater challenge for the practical adaptability of the method can be the availability of real-life data that is a common problem in real option analysis. Practical implications The value of extension and overage options varies greatly between tenants. In general, the property owner can try balance the positive effects from the overage rents to the negative effects of tenant extensions. However, this study tries to highlight that, as usual, using the “law of averages” can result into poor valuation in this context as well. Even the data used in this study provide valuable findings for the property owner as an analytical deduction can be made that certain types of tenants have higher volatilities and this should be acknowledged when valuing options within lease contracts. Originality/value Previous literature in this topic often takes the input data for the option valuation as granted rather than trying to identify the real-life data available for the calculation. This is a common problem in real options valuation and it seems to be one of the reasons why option valuation has not been used widely in practice. This study has used real-life data to assess the problem and more importantly assessed the data across different types of tenants. The volatility spread between different types of tenants has not been discussed previously, even though it has a significant importance when using option pricing in practice.

scholarly journals A Predictive Fleet Management Strategy for On-Demand Mobility Services: A Case Study in Munich

Electronics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1021
Author(s):  
Michael Wittmann ◽  
Lorenz Neuner ◽  
Markus Lienkamp
Keyword(s):  
Service Quality ◽  
Large Scale ◽  
Management Strategies ◽  
Global Market ◽  
Fleet Management ◽  
Bipartite Matching ◽  
Fleet Size ◽  
Original Size ◽  
Real Time Information

The global market for MoD services is in a state of rapid and challenging transformation, with new market entrants in Europe, such as Uber, MOIA, and CleverShuttle, competing with traditional taxi providers. Rapid developments in available algorithms, data sources, and real-time information systems offer new possibilities of maximizing the efficiency of MoD services. In particular, the use of demand predictions is expected to contribute to a reduction in operational costs and an increase in overall service quality. This paper examines the potential of predictive fleet management strategies applied to a large-scale real-world taxi dataset for the city of Munich. A combination of state-of-the art dispatching algorithms and a predictive RHC optimization for idle vehicle rebalancing was developed to determine the scale by which a fleet size can be reduced without affecting service quality. A simulation study was conducted over a one-week period in Munich, which showed that predictive fleet strategies clearly outperform the present strategy in terms of both service quality and costs. Furthermore, the results showed that current taxi fleets could be reduced to 70% of their original size without any decrease in performance. In addition, the results indicated that the reduced fleet size of the predictive strategy was still 20% larger compared to the theoretical optimum resulting from a bipartite matching approach.

Using Deficit Function to Determine the Minimum Fleet Size of an Autonomous Modular Public Transit System

2020 ◽  
Vol 2674 (11) ◽  
pp. 532-541 ◽  
Author(s):  
Tao Liu ◽  
Avishai (Avi) Ceder ◽  
Andreas Rau
Keyword(s):  
Autonomous Vehicles ◽  
Large Scale ◽  
Public Transit ◽  
Programming Model ◽  
Real Life ◽  
Single Line ◽  
Continuum Approximation ◽  
Transit System ◽  
Fleet Size ◽  
Minimum Number

Emerging technologies, such as connected and autonomous vehicles, electric vehicles, and information and communication, are surrounding us at an ever-increasing pace, which, together with the concept of shared mobility, have great potential to transform existing public transit (PT) systems into far more user-oriented, system-optimal, smart, and sustainable new PT systems with increased service connectivity, synchronization, and better, more satisfactory user experiences. This work analyses such a new PT system comprised of autonomous modular PT (AMPT) vehicles. In this analysis, one of the most challenging tasks is to accurately estimate the minimum number of vehicle modules, that is, its minimum fleet size (MFS), required to perform a set of scheduled services. The solution of the MFS problem of a single-line AMPT system is based on a graphical method, adapted from the deficit function (DF) theory. The traditional DF model has been extended to accommodate the definitions of an AMPT system. Some numerical examples are provided to illustrate the mathematical formulations. The limitations of traditional continuum approximation models and the equivalence between the extended DF model and an integer programming model are also provided. The extended DF model was applied, as a case study, to a single line of an AMPT system, the dynamic autonomous road transit (DART) system in Singapore. The results show that the extended DF model is effective in solving the MFS problem and has the potential to be applied to solving real-life MFS problems of large-scale, multi-line and multi-terminal AMPT systems.

MULTICRITERIAL RANKING APPROACH FOR EVALUATING BANK BRANCH PERFORMANCE

2004 ◽  
Vol 03 (02) ◽  
pp. 321-335 ◽  
Author(s):  
FUAD ALESKEROV ◽  
HASAN ERSEL ◽  
REHA YOLALAN
Keyword(s):  
Commercial Bank ◽  
Large Scale ◽  
Real Life ◽  
Multiple Criteria ◽  
Ranking Methods ◽  
Bank Branch ◽  
Bank Branches ◽  
Life Data ◽  
Real Life Data

14 ranking methods based on multiple criteria are suggested for evaluating the performance of the bank branches. The methods are explained via an illustrative example, and some of them are applied to a real-life data for 23 retail bank branches in a large-scale private Turkish commercial bank.

Evaluation of forecasting models for air cargo

2014 ◽  
Vol 25 (3) ◽  
pp. 635-655 ◽  
Author(s):  
Sirikhorn Klindokmai ◽  
Peter Neech ◽  
Yue Wu ◽  
Udechukwu Ojiako ◽  
Max Chipulu ◽  
...  
Keyword(s):  
Real Life ◽  
Air Cargo ◽  
Strategic Development ◽  
Content Type ◽  
Forecasting Models ◽  
Real Life Data ◽  
Accurate Forecast ◽  
Demand Fluctuations ◽  
The Right ◽  
Demand Patterns

Purpose – Virgin Atlantic Cargo is one of the largest air freight operators in the world. As part of a wider strategic development initiative, the company has identified forecasting accuracy as of strategic importance to its operational efficiency. This is because accurate forecast enables the company to have the right resources available at the right place and time. The purpose of this paper is to undertake an evaluation of current month-to-date forecasting utilized by Virgin Atlantic Cargo. The study employed demand patterns drawn from historical data on chargeable weight over a seven-year-period covering six of the company's routes. Design/methodology/approach – A case study is carried out, where a comparison between forecasting models is undertaken using error accuracy measures. Data in the form of historical chargeable weight over a seven-year-period covering six of the company's most profitable routes are employed in the study. For propriety and privacy reasons, data provided by the company have been sanitized. Findings – Preliminary analysis of the time series shows that the air cargo chargeable weight could be difficult to forecast due to demand fluctuations which appear extremely sensitive to external market and economic factors. Originality/value – The study contributes to existing literature on air cargo forecasting and is therefore of interest to scholars examining the problems of overbooking. Overbooking which is employed by air cargo operators to hedge against “no-show” bookings. However, the inability of air cargo operators to accurately predict cargo capacity unlikely to be used implies that operators are unable to establish with an aspect of certainty their revenue streams. The research methodology adopted is also predominantly discursive in that it employs a synthesis of existing forecasting literature and real-life data for accuracy analysis.

scholarly journals Multiple manipulators path planning using double A*

2016 ◽  
Vol 43 (6) ◽  
pp. 657-664 ◽  
Author(s):  
Pedro Tavares ◽  
José Lima ◽  
Pedro Costa ◽  
A. Paulo Moreira
Keyword(s):  
Path Planning ◽  
Real Life ◽  
Robotic Manipulators ◽  
Optimization Methods ◽  
Robotic Manipulator ◽  
New Approach ◽  
Content Type ◽  
Simulation Engine ◽  
Automated Processes ◽  
New System

Purpose Streamlining automated processes is currently undertaken by developing optimization methods and algorithms for robotic manipulators. This paper aims to present a new approach to improve streamlining of automatic processes. This new approach allows for multiple robotic manipulators commonly found in the industrial environment to handle different scenarios, thus providing a high-flexibility solution to automated processes. Design/methodology/approach The developed system is based on a spatial discretization methodology capable of describing the surrounding environment of the robot, followed by a novel path-planning algorithm. Gazebo was the simulation engine chosen, and the robotic manipulator used was the Universal Robot 5 (UR5). The proposed system was tested using the premises of two robotic challenges: EuRoC and Amazon Picking Challenge. Findings The developed system was able to identify and describe the influence of each joint in the Cartesian space, and it was possible to control multiple robotic manipulators safely regardless of any obstacles in a given scene. Practical implications This new system was tested in both real and simulated environments, and data collected showed that this new system performed well in real-life scenarios, such as EuRoC and Amazon Picking Challenge. Originality/value The new proposed approach can be valuable in the robotics field with applications in various industrial scenarios, as it provides a flexible solution for multiple robotic manipulator path and motion planning.

An analysis of the Gezi Park social movement tweets

2017 ◽  
Vol 69 (4) ◽  
pp. 426-440 ◽  
Author(s):  
Selcen Ozturkcan ◽  
Nihat Kasap ◽  
Muge Cevik ◽  
Tauhid Zaman
Keyword(s):  
Data Collection ◽  
Media Coverage ◽  
Large Scale ◽  
Real Life ◽  
Shopping Mall ◽  
Small Scale ◽  
Social Media Analytics ◽  
Public Park ◽  
Content Type ◽  
The Arab Spring

Purpose Twitter usage during Gezi Park Protests, a significant large-scale connective action, is analyzed to reveal meaningful findings on individual and group tweeting characteristics. Subsequent to the Arab Spring in terms of its timing, the Gezi Park Protests began by the spread of news on construction plans to build a shopping mall at a public park in Taksim Square in Istanbul on May 26, 2013. Though started as a small-scale local protest, it emerged into a series of multi-regional social protests, also known as the Gezi Park demonstrations. The paper aims to discuss these issues. Design/methodology/approach The authors sought answers to three important research questions: whether Twitter usage is reflective of real life events, what Twitter is actually used for, and is Twitter usage contagious? The authors have collected streamed data from Twitter. As a research methodology, the authors followed social media analytics framework proposed by Fan and Gordon (2014), which included three consecutive processes; capturing, understanding, and presenting. An analysis of 54 million publicly available tweets and 3.5 million foursquare check-ins, which account to randomly selected 1 percent of all tweets and check-ins posted from Istanbul, Turkey between March and September 2013 are presented. Findings A perceived lack of sufficient media coverage on events taking place on the streets is believed to result in Turkish protestors’ use of Twitter as a medium to share and get information on ongoing and planned demonstrations, to learn the recent news, to participate in the debate, and to create local and global awareness. Research limitations/implications Data collection via streamed tweets comes with certain limitations. Twitter restricts data collection on publicly available tweets and only allows randomly selected 1 percent of all tweets posted from a specific region. Therefore, the authors’ data include only tweets of publicly available Twitter profiles. The generalizability of the findings should be regarded with concerning this limitation. Practical implications The authors conclude that Twitter was used mainly as a platform to exchange information to organize street demonstrations. Originality/value The authors conclude that Twitter usage reflected Street movements on a chronological level. Finally, the authors present that Twitter usage is contagious whereas tweeting is not necessarily.

Travel time prediction in transport and logistics

2019 ◽  
Vol 49 (3) ◽  
pp. 277-306 ◽  
Author(s):  
Xia Li ◽  
Ruibin Bai ◽  
Peer-Olaf Siebers ◽  
Christian Wagner
Keyword(s):  
Travel Time ◽  
Model Fitting ◽  
Real Life ◽  
Gps Data ◽  
Travel Time Prediction ◽  
Time Data ◽  
Content Type ◽  
Time Prediction ◽  
Travel Time Data ◽  
Real Life Data

Purpose Many transport and logistics companies nowadays use raw vehicle GPS data for travel time prediction. However, they face difficult challenges in terms of the costs of information storage, as well as the quality of the prediction. This paper aims to systematically investigate various meta-data (features) that require significantly less storage space but provide sufficient information for high-quality travel time predictions. Design/methodology/approach The paper systematically studied the combinatorial effects of features and different model fitting strategies with two popular decision tree ensemble methods for travel time prediction, namely, random forests and gradient boosting regression trees. First, the investigation was conducted using pseudo travel time data that were generated using a pseudo travel time sampling algorithm, which allows generating travel time data using different noise processes so that the prediction performance under different travel conditions and noise characteristics can be studied systematically. The results and findings were then further compared and evaluated through a real-life case. Findings The paper provides empirical insights and guidelines about how raw GPS data can be reduced into a small-sized feature vector for the purposes of vehicle travel time prediction. It suggests that, add travel time observations from the previous departure time intervals are beneficial to the prediction, particularly when there is no other types of real-time information (e.g. traffic flow, speed) are available. It was also found that modular model fitting does not improve the quality of the prediction in all experimental settings used in this paper. Research limitations/implications The findings are primarily based on empirical studies on limited real-life data instances, and the results may lack generalisabilities. Therefore, the researchers are encouraged to test them further in more real-life data instances. Practical implications The paper includes implications and guidelines for the development of efficient GPS data storage and high-quality travel time prediction under different types of travel conditions. Originality/value This paper systematically studies the combinatorial feature effects for tree-ensemble-based travel time prediction approaches.

Centralized vehicle leasing in humanitarian fleet management: the UNHCR case

2015 ◽  
Vol 5 (3) ◽  
pp. 387-404 ◽  
Author(s):  
Nathan Kunz ◽  
Luk N. Van Wassenhove ◽  
Rob McConnell ◽  
Ketil Hov
Keyword(s):  
Poor Performance ◽  
Fleet Management ◽  
Longitudinal Case Study ◽  
Content Type ◽  
Fleet Size ◽  
Humanitarian Organizations ◽  
High Commissioner ◽  
Before And After ◽  
Negative Impacts

Purpose – Fleet management is a key function in humanitarian organizations, but is not always recognized as such. This results in poor performance and negative impacts on the organization. The purpose of this paper is to demonstrates how the UN High Commissioner for Refugees (UNHCR) managed to substantially improve its fleet management through the introduction of an Internal Leasing Program (ILP), in which headquarters procures vehicles and leases them to field offices. Design/methodology/approach – This paper develops a framework for fleet management based on a longitudinal case study with UNHCR. It compares fleet performance indicators before and after implementation of an ILP. Findings – At UNHCR, vehicle procurement was driven by availability of funding. Fleet management was highly decentralized and field offices had limited awareness of its importance. These systems and behaviors led to major challenges for the organization. The introduction of the ILP positively impacted fleet management at UNHCR by reducing fleet size, average age of fleet and procurement costs. Practical implications – This paper provides fleet managers with a tool for analyzing their fleet. The frameworks and actions described in this paper contain practical recommendations for achieving a well-performing fleet. Originality/value – This paper is the first to analyze fleet management before and after introduction of an ILP. It describes the benefits of this model based on empirical data, and develops frameworks to be used by researchers and practitioners.

A study identifying factors influencing decision making in dynamic emergencies like urban fire and rescue settings

2014 ◽  
Vol 3 (2) ◽  
pp. 144-161 ◽  
Author(s):  
David Launder ◽  
Chad Perry
Keyword(s):  
Decision Making ◽  
Situation Awareness ◽  
Large Scale ◽  
Real Life ◽  
Research Problem ◽  
Management Decision ◽  
Incident Management ◽  
Decision Strategy ◽  
Content Type ◽  
Urban Fire

Purpose – There has been little research about incident management decision making within real-life, dynamic emergencies such as urban fire settings. So this research addresses the research problem: how do incident managers make decisions in urban fire settings? These decision behaviours cover five areas: assessment of the fireground situation, selection of a decision strategy, determination of incident objectives, deployment and management of firefighting resources and ongoing review of the incident. The paper aims to discuss these issues. Design/methodology/approach – Case research was used to examine management of different types of fires, through in-depth interviews with a range of incident managers. Findings – This research identified five key behavioural elements associated with incident management in urban fire settings such as their application of a mix of recognition-primed, value based, procedural and formal decision strategies throughout the course of an incident rather than a single style. Research limitations/implications – The in-depth framework of decision making could provide foundations for later research about other emergency settings. And this research is limited to analytic generalisation (Yin, 2009); so quantitative research such as surveys and large scale interviews could be done to further extend the research for statistical generalisation. Practical implications – The decision procedures uncovered in this research will assist incident managers in many emergencies, assist policy making and foster the development of future incident managers. Originality/value – The findings expand the knowledge of how incident managers develop situation awareness, make decisions and plans, implement them, and review the incident as it evolves. Another contribution is the comprehensive framework of decision making developed from these findings.

Sign in / Sign up

Export Citation Format

Share Document