Heuristics for the distributed blocking Ffow shop scheduling problem

Postprint (published version

Synergies between app-based car-related shared mobility services for the development of more profitable business models

Purpose: Emerging shared mobility services are an opportunity for cities to reduce the number of car single trips to both improve traffic congestion and the environment. Users of shared mobility services, such as carsharing, ridesharing and singular and shared ride-hailing services, often need to be customers of more than one service to cover all their transport needs, since few mobility providers offer more than one of these services from a single platform. On the other hand, providers offering these services separately do not optimize costly resources and activities, such as the vehicles or the technology. Hence, the aim of this paper is to find synergies between the different app-based car-related shared mobility services that foster the development of new business models, to increase the profitability of these services. Design/methodology/approach: The research approach is built on the literature of car-related shared mobility services business models, supported by the review of certain outstanding services websites, and face-to-face interviews with users and drivers of these transport services. The analysis is presented by means of the Business Model Canvas methodology. Findings: Based on the synergies found, this paper suggests a few different approaches for services to share some resources and activities. Originality/value: This study identifies the common features of carsharing, ridesharing and singular and shared ride-hailing services to develop more profitable business models, based on providing the services in aggregated form, or outsourcing activities and resources. In addition, the implications of these proposals are discussed as advantages and drawbacks from a business perspectivePeer ReviewedPostprint (published version

A Model to Align Organizational Culture to Lean Culture

Purpose: Since the emergence of Lean Manufacturing many organizations strived to implement it. Nonetheless, sustainable Lean transformation is not as easy as to be simply achieved. Several aspects need to be taken into account before Lean implementation which national and organizational culture are important. By considering influences of national culture on the organizational culture, this paper aims at proposing an evaluation model to determine the cultural weaknesses of an organization and give some recommendations to manage people before implementing Lean. Design/methodology/approach: This research has been conducted based on literature review survey and semi-structured interviews. Research papers, conference proceedings, books, and official websites regarding Lean philosophy were reviewed to find the influence of national culture in Lean implementation. Different databases were scrutinized, from 2015 to 2017, containing Scopus and Web of Science with the time period of 1996-2016. A set of key terms and their combinations were used including: Toyota Production system, Lean production, Lean manufacturing, Lean management, Transformation, Implementation, Barriers/ Impediments/Challenges/Difficulties, Human resources, Success factors, Organizational culture, and National culture. Findings: The proposed evaluation model is a guide for organizations to determine cultural misalignments between the corporate culture and the Lean culture before its implementation and gives some managerial recommendations to correct them. Originality/value: This study is the first attempt to integrate the national models with Lean culture to provide an evaluation model and some recommendations to help the organization to align its culture to Lean culture before its implementation.Peer Reviewe

Models de negoci entorn el vehicle elèctric: reptes i oportunitats

En els darrers anys les vendes de Vehicles Elèctrics (VE) han experimentat un increment considerable. Si ens fixem només en Europa, les vendes de cotxes elèctric i híbrids endollables, fins a finals d’octubre de 2019, es van incrementar per sobre del 39% respecte les vendes del període Q1-Q3 de l’any anterior, tot i que a Espanya aquest increment va ser només del 6%Postprint (author's final draft

Efficient heuristic algorithms for the blocking flow shop scheduling problem with total flow time minimization

This paper proposes two constructive heuristics, i.e. HPF1 and HPF2, for the blocking flow shop problem in order to minimize the total flow time. They differ mainly in the criterion used to select the first job in the sequence since, as it is shown, its contribution to the total flow time is not negligible. Both procedures were combined with the insertion phase of NEH to improve the sequence. However, as the insertion procedure does not always improve the solution, in the resulting heuristics, named NHPF1 and NHPF2, the sequence was evaluated before and after the insertion to keep the best of both solutions. The structure of these heuristics was used in Greedy Randomized Adaptive Search Procedures (GRASP) with variable neighborhood search in the improvement phase to generate greedy randomized solutions. The performance of the constructive heuristics and of the proposed GRASPs was evaluated against other heuristics from the literature. Our computational analysis showed that the presented heuristics are very competitive and able to improve 68 out of 120 best known solutions of Taillard’s instances for the blocking flow shop scheduling problem with the total flow time criterionPeer ReviewedPostprint (author’s final draft

A note on the paper ‘Demonstrating Johnson’s algorithm via resource constrained scheduling’

In this paper we demonstrate that the relation between two jobs defined by min{ai, bj}=min{bi, aj}, used in Johnson’s theorem, is not transitive. However, both the theorem and Johnson’s algorithm are correct.Peer ReviewedPostprint (author's final draft

Main design factors for shared ride-hailing services from a user perspective

Shared ride-hailing transportation is discreetly emerging in cities all over the world with the purpose of decongesting cities, offering a similar comfort and convenience of the private car, and this way, filling the gap between the cities’ bus services and the regular taxi services. Hence, the aim of this research is to detect the main factors that should be taken into account for the service design of shared ride- hailing transportation, as well as to compare this mean of transport with the bus and taxi services. The research was conducted through, first, an analysis of shared ride-hailing services business model. Then, a quantitative research was conducted to users of a small-scale one-week pilot in Barcelona. The results show that factors related to price and travel times are more important from a user perspective than the ones related to comfort, such as the walking distance to the pickup point or the comfort provided by the vehicle. Furthermore, results indicate the intended use of participants of a potential future shared ride-hailing service in different use casesPostprint (author's final draft

Newinsights on the blocking flow shop problem best solutions updated

update of the best solution for Taillard's instances on the blocking flow shop problemPreprin

A hybrid flow shop model for an ice cream production scheduling problem

In this paper we address the scheduling problem that comes from an ice cream manufacturing company. This production system can be modelled as a three stage nowait hybrid flow shop with batch dependent setup costs. To contribute reducing the gap between theory and practice we have considered the real constraints and the criteria used by planners. The problem considered has been formulated as a mixed integer programming. Further, two competitive heuristic procedures have been developed and one of them will be proposed to schedule in the ice cream factoryPeer Reviewe

A new constructive heuristic for the Fm|block|¿T

This paper deals with the blocking flow shop problem and proposes new constructive procedure s for the total tardiness minimization of jobs. The heuristic has three - phases to build the sequence; the first phase selects the first job to be scheduled, the second phase ar ranges the remaining jobs and the third phase uses the insertion procedure of NEH to improve the sequence. T he proposed proce- dures evaluate the tardiness associated to the sequence obtained before and after the third phase in order to keep the best of both because , we have observed , that the insertion phase can worsen the result . The c omputational evaluation of these procedures against the benchmark constructive procedures from the literature re- veals their good performancePostprint (published version