Balancing and scheduling tasks in assembly lines with sequence-dependent setup times

The classical Simple Assembly Line Balancing Problem (SALBP) has been widely enriched over the past few years with many realistic approaches and much effort has been made to reduce the distance between the academic theory and the industrial reality. Despite this effort, the scheduling of the execution of tasks assigned to every workstation following the balancing of the assembly line has been scarcely reported in the scientific literature. This is supposed to be an operational concern that the worker should solve himself, but in several real environments, setups between tasks exist and optimal or near-optimal tasks schedules should be provided inside each workstation. The problem presented in this paper adds sequence-dependent setup time considerations to the classical SALBP in the following way: whenever a task is assigned next to another at the same workstation, a setup time must be added to compute the global workstation time. After formulating a mathematical model for this innovative problem and showing the high combinatorial nature of the problem, eight different heuristic rules and a GRASP algorithm are designed and tested for solving the problem in reasonable computational time.Peer Reviewe

Exact and heuristic methods for solving the Robotic Assembly Line Balancing Problem

[EN] In robotic assembly lines, the task times depend on the robots assigned to each station. Robots are considered an unlimited resource and multiple robots of the same type can be assigned to different stations. Thus, the Robotic Assembly Line Balancing Problem (RALBP) consists of assigning a set of tasks and a type of robot to each station, subject to precedence constraints between the tasks. This paper proposes a lower bound, and exact and heuristic algorithms for the RALBP. The lower bound uses chain decomposition to explore the graph dependencies. The exact approaches include a novel linear mixed-integer programming model and a branch-bound-and-remember algorithm with problem-specific dominance rules. The heuristic solution is an iterative beam search with the same rules. To fully explore the different characteristics of the problem, we also propose a new set of instances. The methods and algorithms are extensively tested in computational experiments showing that they are competitive with the current state of the art. (C) 2018 Elsevier B.V. All rights reserved.Borba, L.; Ritt, M.; Miralles Insa, CJ. (2018). Exact and heuristic methods for solving the Robotic Assembly Line Balancing Problem. European Journal of Operational Research. 270(1):146-156. https://doi.org/10.1016/j.ejor.2018.03.011S146156270

The use of employee participation in the USA and Spanish companies

This article presents a description of employee participation in Spain. The number of published papers in English about Spain regarding this subject is very low, and even lower by Spanish authors. In short, we can say that there is hardly any knowledge regarding employee participation in Spain in both the European and American settings. This paper summarized the results of a research project we carried out whose objective was to compare employee participation using samples from large American and Spanish companies following the works of Edward E. Lawler and his team. Our aim is to have professionals and researchers throughout the world better understand the actual situation in our country

Two extensions for the ALWABP: Parallel stations and collaborative approach

[EN] In this article, we introduce two new variants of the ALWABP that allow parallelization of and collaboration between heterogeneous workers. These new approaches suppose an additional level of complexity in the Line Design and Assignment process, but also higher flexibility; which may be particularly useful in practical situations where the aim is to progressively integrate slow or limited workers in conventional assembly lines. We present linear models and heuristic procedures for these two new problems. Computational results show the efficiency of the proposed approaches and the efficacy of the studied layouts in different situations.This research was supported by CAPES-Brazil and MEC-Spain (coordinated project CAPES-DGU 258-12/PHB-0012-PC) and by FAPESP-Brazil. We also thank the project ‘‘CORSARI MAGIC DPI2010-18243’’ of the Ministerio de Ciencia e Innovación del Gobierno de España within the Program ‘‘Proyectos de Investigación Fundamental No Orientada’’.Araujo, FF.; Costa, AM.; Miralles Insa, CJ. (2012). Two extensions for the ALWABP: Parallel stations and collaborative approach. International Journal of Production Economics. 140(1):483-495. https://doi.org/10.1016/j.ijpe.2012.06.032S483495140

Balancing parallel assembly lines with disabled workers

[EN] In this paper, we study an assembly line balancing problem that occurs in sheltered worker centres for the disabled, where workers with very different characteristics are present. We are interested in the situation in which complete parallel assembly lines are allowed and name the resulting problem as parallel assembly line worker assignment and balancing problem (PALWABP). This approach enables many new possible worker-tasks assignments, what is beneficial in terms of both labour integration and productivity. We present a linear mixed-integer formulation and two heuristic solution methods: one is based on tabu search and the other is a biased random-key genetic algorithm (BRKGA). Computational results with a large set of instances recently proposed in the literature show the advantages of allowing such alternative line layouts.This research was supported by CAPES-Brazil and MEC-Spain (coordinated project CAPES DGU 258-12/PHB2011-0012-PC) and by FAPESP-Brazil. The authors thank Dr. Marcus Ritt, from Universidade Federal do Rio Grande do Sul (UFRGS - Brazil), for providing the optimal solutions for the serial ALWABP. The authors also thank three anonymous reviewers for their comments which have helped improve this paper.Araujo, FFB.; Costa, AM.; Miralles Insa, CJ. (2015). Balancing parallel assembly lines with disabled workers. European J of Industrial Engineering. 9(3):344-365. https://doi.org/10.1504/EJIE.2015.069343S3443659

Oral presentation and assessment skills in engineering education

This study examines the possibilities of including students in the assessment process and the conclusions drawn from the experiences of the academic year 2004±05. The fieldwork focuses on examining the reliability of the marks given by students in relation to those given by the lecturer. Similarly, the marks given by the subject lecturer are examined with those assigned by four external markers. In each presentation the assessment of several markers is also studied, whether they are students or lecturers. The results obtained seem to indicate that students can be adequate markers for their peers' oral presentations. Also in their assessments, few significant differences are seen from those suggested by the subject lecturer.Educació

Diseño de puestos de trabajo complejos. Equilibrado de la capacidad e interferencias

En Vicens-Salort, E. y otros (2010) se estudió el diseño de Puestos de Trabajo Simples. Se establecía que para incrementar la productividad de un recurso de fabricación, como la mano de obra, se podían utilizar dos estrategias. La primera, cuyo objetivo es reducir la demora de proceso (DP) del sistema, se podría basar en la asignación de varias máquinas a un mismo operario. La segunda, cuyo objetivo es reducir la demora inherente (DI) del sistema, se basaría en el equilibrado de las diferentes capacidades (Cap) y tiempos de ciclo (TC) entre los elementos que constituyen el sistema. Aquí se pretende estudiar estas dos estrategias de mejora de la productividad en un sistema de fabricación: la reducción de las demoras de procesos mediante Asignación Multimáquina y la reducción de la Demora Inherente mediante el Equilibrado y ajuste de los tiempos de ciclo al Tiempo de Ciclo Requerido (o Tackt Time) determinado por la demanda de los productos que se fabrican. Previamente se definen algunos conceptos nuevos como el de Puesto de Trabajo Complejo y el de Batería de recursos.Vicens Salort, E.; Andrés Romano, C.; Miralles Insa, CJ. (2015). Diseño de puestos de trabajo complejos. Equilibrado de la capacidad e interferencias. http://hdl.handle.net/10251/5087

Modelo de Negocio Triplemente Sostenible. Caso de Estudio en la venta directa de alimentos ecológicos.

[EN] The present work aims to analyse and identify a triple bottom-line business model of food retailing, in order to show a sustainable, replicable and non-scalable model in the agri-food sector, and to facilitate the development of a feasible market for small size producers-sellers. The methodology used for the business model identification analyses and relates elements and strategies, providing a design graphic for the model, as well as evaluating each triple sustainability dimension. All this following a protocol derived from the methodology of case study research. The case study shows a sustainable, replicable and non-scalable business model that emerges from a strategy defined by a responsible consumption group from a university. Using digital technology for the distribution and sale of products, and sharing capacity with a WISE, a business model is achieved that shortens the food products commercialization channel between producers and consumers, improving economic, social and environmental sustainability. The application of this methodology provides a tool that facilitates the replicability of sustainable business models in the agri-food business context, and allows identifying the level of their sustainability. The incorporation of this business model can contribute to the development of a triple bottom-line food market, whose purpose is to improve the survival of small size producers-sellers given the increasing centralization and globalization of the agro-food economy distribution.[EN] El presente trabajo tiene como objetivo analizar e identificar un modelo de negocio triplemente sostenible de venta de alimentos minorista, con el fin de mostrar un modelo sostenible, replicable y no escalable en el sector agroalimentario, y que facilite el desarrollo de un mercado viable para el pequeño productor-vendedor. En la identificación y el análisis del modelo de negocio se utiliza una metodología que analiza y relaciona elementos y estrategias proporcionando un diseño gráfico del modelo, además de una evaluación de cada dimensión de la triple sostenibilidad. Todo ello siguiendo un protocolo derivado de la metodología de investigación de casos de estudio. El caso de estudio muestra un modelo de negocio sostenible, replicable y no escalable, que surge de una estrategia definida por un grupo de consumo responsable de una universidad. Utilizando tecnología digital para la distribución y venta de los productos, y capacidad compartida con un centro especial de empleo, se consigue un modelo de negocio que acorta el canal de comercialización de productos alimenticios entre productores y consumidores, mejorando la sostenibilidad económica, social y ambiental. La aplicación de esta metodología proporciona una herramienta que facilita la replicabilidad de modelos de negocio sostenibles en el tejido empresarial agroalimentario y permite identificar el nivel de sostenibilidad de los mismos. La incorpo-ración de este modelo de negocio puede contribuir al desarrollo de un mercado triplemente sostenible de productos alimentarios, que tiene como finalidad mejorar la pervivencia del pequeño productor-vendedor ante la creciente centralización y globalización de la distribución en la economía agroalimentaria.Galeano Revert, A.; García-Sabater, JP.; Miralles Insa, C. (2018). Triple Bottom-line Business Model. Case study on the organic food retailing. Working Papers on Operations Management. 9(1):30-52. doi:10.4995/wpom.v9i1.9131SWORD305291Baden-Fuller, C., & Morgan, M. S. (2010). Business Models as Models. Long Range Planning, 43(2-3), 156-171. http://doi.org/10.1016/j.lrp.2010.02.005Bagnoli, L., & Megali, C. (2009). Measuring performance in social enterprises. Nonprofit and Voluntary Sector Quarterly., 40(1), 149-165. https://doi.org/10.1177/0899764009351111Barney, J. B., & Hesterly, W. (2015). Strategic management and competitive advantage concepts and cases. Pearson.Busch, G., & Spiller, A. (2015). Farmer share and fair distribution in food chains from a consumer's perspective. Journal of Economic Psychology, 55, 149-158. http://doi.org/10.1016/j.joep.2016.03.007Casadesus-Masanell, R., & Ricart, J. (2010). From Strategy to Business Models and onto Tactics. Long Range Planning, 43(2-3), 195-215. http://doi.org/10.1016/j.lrp.2010.01.004Chatterjee, S. (Author). (2013). Simple Rules for Designing Business Models. California Management Review. Winter2013, 55(2), 97-124. 28p. 1 Black and White Photograph. http://doi.org/10.1525/cmr.2013.55.2.97Dittrich, P. (funcionaria federal de agricultura de la C. S. (2010). Agricultura ecológica. Nota informativa. Retrieved from https://ec.europa.eu/europeaid/sites/devco/files/study-organic-agriculture-201206_es_5.pdfElkington, J. (2004). Enter the triple bottom line. The Triple Bottom Line: Does It All Add up, 11(12), 1-16.Galeano Revert, AM. (2013). Identificar y analizar modelos de negocio a través de la metodologia de los casos de estudio. Una revision del estado del arte y propuesta premilinar. Universitat Politècnica de València. http://hdl.handle.net/10251/35065Galeano Revert, AM. (2017). Propuesta de metodologia para la identificacion y el analisis de modelos de negocio triplemente sostenibles en el sector agroalimentario (Tesis doctoral no publicada) Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/88395Galli, F., & Brunori, G. (2013). Short Food Supply Chains as drivers of sustainable development. Evidence Document. Evidence Document. Retrieved from http://www.foodlinkscommunity.net/fileadmin/documents_organicresearch/foodlinks/CoPs/evidence-document-sfsc-cop.pdfGarcia-Sabater, J., & Garcia-Sabater, J. P. (2017). Fundación Espurna: A Case Study on Social Entrepreneurship. In Social Entrepreneurship in Non-Profit and Profit Sectors (pp. 73-83). Springer International Publishing. https://doi.org/10.1007/978-3-319-50850-4_6Grassl, W. (2012). Business Models of Social Enterprise: A Design Approach. ACRN Journal of Entrepreneurship Perspectives, 1(1), 37-60.Hopwood, B., Mellor, M., & O'Brien, G. (2005). Sustainable development: mapping different approaches. Sustainable Development, 13(1), 38-52. https://doi.org/10.1002/sd.244Hubbard, G. (2009). Measuring organizational performance: beyond the triple bottom line. Business Strategy and the Environment, 18(3), 177-191. https://doi.org/10.1002/bse.564Lee, J. H., Shin, D. I., Hong, Y. S., & Kim, Y. S. (2011). Business Model Design Methodology for Innovative Product-Service Systems: A Strategic and Structured Approach. 2011 Annual SRII Global Conference, 663-673. https://doi.org/10.1109/SRII.2011.72Malthus, T. R. (1846). Ensayo sobre el principio de la población. (L. Gonzalez., Ed.).Mikhalkina, T., & Cabantous, L. (2015). Business Models and Modelling. (C. Baden-Fuller & V. Mangematin, Eds.)Advances in Strategic Management (Vol. 33). Emerald Group Publishing Limited. http://doi.org/10.1108/S0742-3322201533Miralles Insa, C., & Puchades Pla, R. (2016). La Universidad y su rol en la integración laboral . Visión global y experiencias locales en la UPV, 1-19.Monzón, J. L. (2006). Economía Social y conceptos afines: fronteras borrosas y ambigüedades conceptuales del Te rcer Sector. CIRIEC-España, Revista de Economía Pública, Social Y Cooperativa, 56, 9-24.Monzón Campos, J. L. (2013). Social enterprises and social economy: Their boundaries and methodological proposals for measuri ng their socioeconomic impact in the E.U. | Empres as sociales y economía social: Perímetro y propues tas metodológicas para la medición de su i mpacto socioe. Revista de Economia Mundial, (35).Norman, W., & MacDonald, C. (2004). Getting to the bottom of "triple bottom line. 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A Cloud robotics architecture to foster individual child partnership in medical facilities

Robots and automation systems have become a valuable partner in several facets of human life: from learning and teaching, to daily working, including health monitoring and assistance. So far, these appealing robot-based applications are restricted to conduct repetitive, yet useful, tasks due to the reduced individual robots’ capabilities in terms of processing and computation. This concern prevents current robots from facing more complex applications related to understanding hu- man beings and perceiving their subtle feelings. Such hardware limitations have been already found in the computer science field. In this domain, they are currently being addressed using a new resource exploitation model coined as cloud computing, which is targeted at enabling massive storage and computation using smartly connected and inexpensive commodity hardware. The purpose of this paper is to propose a cloud-based robotics architecture to effectively develop complex tasks related to hospitalized children assistance. More specifically, this paper presents a multi-agent learning system that combines machine learning and cloud computing using low-cost robots to (1) collect and perceive children status, (2) build a human-readable set of rules related to the child-robot relationship, and (3) improve the children experience during their stay in the hos- pital. Conducted preliminary experiments proof the feasibility of this proposal and encourage practitioners to work towards this direction.Peer ReviewedPostprint (published version