An agent-based model of competition and collaboration in supply chains

This paper proposes an agent-based simulation model to study how competition and collaboration affect supply chains by looking at the problem at a market level. A theory-driven approach is applied to the modelling. The model reflects customers, manufacturers, and suppliers competing and collaborating in a supply chain strategic space. Preliminary results show that the market structure is determined primarily by bounded-rational behaviours of the supply chains and not by demand. This study is expected to provide a new perspective for understanding the implications of firms’ behaviour as supply chains to the market. It is also intended to act as a building block to study more complex and real supply chains, and encourage academics, business managers, and market regulators to invest time in studying the impact of competition and collaboration strategies in supply chains

An agent-based model of supply chain collaboration: Investigating manufacturer loyalty

Collaboration is considered to be a key driver to supply chain success. However, the ideal collaboration practice is difficult to achieve. Firms’ strategy and behaviour in supply chain collaborations are identified as the main reasons for supply chain failure. To study this problem, we use an agent-based model which represents two-stage supply chains, consisting of customers, manufacturers, and suppliers. The firms exist in a two-dimension supply chain strategic space defined by efficiency and responsiveness. In this paper, we examine the effect of manufacturer loyalty on supply chains’ performance in an innovative products market from system perspective. Measuring the supply chains fill rate and number of surviving supply chains in the market, the results indicate that manufacturer loyalty at intermediate levels does not seem to guarantee supply chain success in a market of innovative products, unless it is very high or does not exist at all

ANALISIS RISIKO PADA RANTAI PASOK SUSU: SEBUAH PENDEKATAN MODEL BERBASIS AGEN

Usaha-usaha pertanian pada umumnya menghadapi banyak risiko dan ketidakpastian. Hal ini mengharuskan para pelaku usaha pertanian untuk membuat banyak keputusan produksi dibawah tekanan risiko tersebut. Oleh karena itu, keberadaan risiko diperkirakan memiliki keterkaitan yang erat dengaan kinerja produksi. Penelitian ini bermaksud untuk mengidentifikasi sumber-sumber risiko di dalam usaha sapi perah serta memperkirakan dampaknya terhadap kinerja rantai pasok susu secara keseluruhan. Survey telah dilakukan di wilayah produksi susu sapi di Kabupaten Bandung dalam periode bulan Oktober sampai dengan Desember tahun 2016. Data diperoleh melalui wawancara terhadap 154 peternak sapi perah di wilayah tersebut. Sumber-sumber risiko ditentukan dengan menggunakan teknik analisis komponen pokok (PCA), sementara perkiraan dampaknya terhadap kinerja produksi diperoleh melalui pemodelan berbasis agen (ABM). Hasil analisis menunjukkan bahwa faktor yang dianggap paling signifikan dalam mempengaruhi kinerja produksi adalah risiko menurunnya ketersediaan sumberdaya pakan dari waktu ke waktu. Berdasarkan simulasi model, faktor ini diyakini juga menjadi pemicu timbulnya faktor-faktor risiko lainnya. Kondisi ini menunjukkan bahwa hampir seluruh risiko yang ada di dalam rantai pasok susu berkaitan antara satu dan lainnya secara sistemik. Sebagai implikasinya, pengelolaan risiko rantai pasok susu tidak dapat dilakukan secara parsial melainkan holistik

Study on how to increase the effectiveness of maritime interdiction operations to reduce the resilience of the drug trafficking logistics network

El tráfico de drogas ilegales es un negocio criminal resiliente que afecta a muchos países a pesar de los grandes esfuerzos por parte de los gobiernos para contenerlo. Dentro de estos esfuerzos, la Armada Nacional emplea las operaciones de interdicción marítima (OIM) como la principal herramienta para combatir la cadena logística del narcotráfico. En la presente investigación se propone un modelo de simulación basada en agentes (ABMS) que permite hallar la “mejor localización y configuración” de los Sistemas de Aeronaves Remotamente Pilotadas (RPAS) empleados en la lucha contra este flagelo. Para este propósito se utilizó el software NetLogo como plataforma para la simulación y Minitab con herramienta estadística para tratar los datos obtenidos en un experimento factorial completo de dos niveles. Los resultados demostraron que, primero, la localización y configuración de los RPAS influyen en la efectividad de las OIM, y segundo, la aplicación de una estrategia de ubicación por centro de gravedad favorece la mejora de los indicadores de afectación a la resiliencia de las rutas del narcotráfico. Finalmente, el modelo propuesto puede usarse como herramienta para tomar decisiones sobre la localización de bases de lanzamiento y selección de RPAS que participen en OIM.Illegal drug trafficking is a resilient criminal business that affects many countries despite great efforts by governments to contain it. Within these efforts, the National Navy uses maritime interdiction operations (MIO) as the main tool to combat the logistic chain of drug trafficking. In the present investigation, an agent-based simulation model (ABMS) is proposed that allows finding the "best location and configuration" of the Remotely Piloted Aircraft Systems (RPAS) used in the fight against this scourge. For this purpose, the NetLogo software was used as a platform for the simulation and Minitab with a statistical tool to treat the data obtained in a complete two-level factorial experiment. The results showed that, first, the location and configuration of the RPAS influence the effectiveness of the MIO, and second, the application of a location strategy by center of gravity favors the improvement of the indicators affecting the resilience of the routes of drug trafficking. Finally, the proposed model can be used as a tool to make decisions about the location of launch bases and the selection of RPAS that participate in MIO.Maestrí

Construction Site-Layout Optimization Considering Workers' Behaviors Around Site Obstacles, Using Agent-Based Simulation

The majority of construction projects, especially large ones, experience time delays, cost overruns, productivity loss, and/or accidents. This is particularly so in case of congested and disorganized sites that contain obstacles that affect workers’ productivity and safety. Effective site layout planning, therefore, is one of the most important project management tasks, and has a significant impact on all aspects of construction, including safety, productivity, site operations, and ultimately time and cost. Site layout planning is a complex process that determines the best location for the needed site facilities (e.g., workshops, storage areas, equipment, etc.) needed to execute the project, so that productivity and safety are optimized. Despite the many simulation and optimization models in the literature for site layout planning, they mostly consider the site location without the low-level details of the workers’ movements within site, particularly around site obstacles. This research aims at developing a construction site-layout planning framework that uses Agent-Based Modelling and Simulation (ABMS) technology to perform a micro-level analysis of workers’ movements and behaviors on site, to study the impact on site productivity and safety. For practicality, this research considers variety of productivity-hindering and safety-hindering obstacles on site. The model also considers two types of workers’ behaviors in their movement around site obstacles: avoider, and aggressive. Given any site layout with any number of resources of different behaviors, the ABMS simulation quantifies the site overall productivity and accident/injury potential. To optimize the site layout, the framework integrates an optimization procedure that determines the optimum site layout that maximizes productivity and safety. A sensitivity analysis is also incorporated to examine the impact of obstacle type and workers’ behavioral characteristics. The results of two case studies prove that the framework is a valuable tool for analyzing and assessing site productivity and safety, and for providing decision support for project managers in establishing site regulations and rewards for positive workers’ behaviors. This research is expected to help construction companies deliver projects with less time and cost, and help to reduce accidents on complex sites

Análise da Representação do Fator Humano presente em um Sistema de Manufatura através da Simulação Híbrida.

Os sistemas de manufatura são sistemas complexos, onde ocorrem diversas ações voltadas para a transformação de matérias-primas em produtos de valor agregado. Dentro deles, ocorrem processos de transformação envolvendo pessoas, máquinas e equipamentos, sistemas computacionais, processos e planejamento. No ambiente manufatureiro, os recursos humanos desempenham um papel relevante e, nesse sentido, diversas pesquisas abordando o elemento humano em seu ambiente de trabalho foram desenvolvidas e abordadas sob diferentes pontos de vista. Uma dessas pesquisa é o estudo de tempos e movimentos, que trata, dentre outros assuntos, da questão do ritmo de trabalho. É verdade que o comportamento humano é regido por princípios complexos. Esse fato corrobora a dificuldade em modelar o comportamento humano. Dentro da área de modelagem e simulação, representar o elemento humano através de seu comportamento é um dos principais desafios. Na Simulação a Eventos Discretos (SED), a modelagem mais detalhada do elemento humano é difícil de se realizar. Logo, o elemento humano em modelos de SED é considerado como recurso simples. Essa dificuldade em modelar o elemento humano pode ser superada com a Simulação Baseada em Agentes (SBA). A SBA é uma nova abordagem de modelagem e simulação que surgiu recentemente. Ela traz a oportunidade de modelar o comportamento humano de maneira mais detalhada. Além dessa oportunidade, a SBA ainda pode ser combinada com a SED, dando origem à simulação híbrida. A combinação dessas duas abordagens distintas de simulação proporciona ao pesquisador a oportunidade de simular características relevantes do sistema real. Portanto, essa pesquisa de dissertação almeja contribuir cientificamente na área de simulação e de sistemas de produção trazendo uma análise sobre a representação do fator humano em um sistema de manufatura através da simulação híbrida. Nessa pesquisa, a combinação dessas duas abordagens ocorrerá dentro do contexto metodológico da Modelagem e Simulação por meio da adaptação da fase conceitual que faz parte da sequência de passos sugeridos para projetos de simulação. Essa proposta de adaptação tem como objetivo auxiliar a construção de modelos híbridos de simulação. O sistema real de manufatura que foi modelado e simulado é uma linha de montagem composta por dez postos de trabalho e quatorze operadores. Esses quatorze operadores são representados no modelo híbrido como agentes. Tendo como base o Sistema Westinghouse para avaliação do ritmo, cada agente possui um ritmo de trabalho que se altera no decorrer da simulação em função da meta diária de trabalho. Por meio dos resultados do modelo híbrido, nota-se que os agentes agem dentro do modelo de maneira autônoma e tomam decisões com base nas metas de produção. Assim, pode-se concluir que é possível superar o desafio de retratar o fator humano no contexto fabril utilizando a simulação híbrida como ferramenta

Competition and collaboration in supply chains: an agent-based modelling approach

Competition has been considered as an effective means to improve business and economic competitiveness. However, competition in supply chain management (SCM) can be viewed as a source of uncertainty. Most recommended collaboration strategies in SCM literature tend to avoid the emergence of competition inside the supply chain, but, in reality, these strategies do not lead all supply chains to success. In addition, from strategic management perspective, these collaboration strategies are not believed to encourage firms to improve their performance. Both competition and collaboration are critical issues in achieving business success, but the effect of both factors on the market has not been explored concurrently in the literature. The complexity of this issue should be investigated using a comprehensive perspective, and it is hard to undertake by using an empirical approach. [Continues.

Historia, evolución y perspectivas de futuro en la utilización de técnicas de simulación en la gestión portuaria: aplicaciones en el análisis de operaciones, estrategia y planificación portuaria

Programa Oficial de Doutoramento en Análise Económica e Estratexia Empresarial. 5033V0[Resumen] Las técnicas de simulación, tal y como hoy las conocemos, comenzaron a mediados del siglo XX; primero con la aparición del primer computador y el desarrollo del método Monte Carlo, y más tarde con el desarrollo del primer simulador de propósito específico conocido como GPS y desarrollado por Geoffrey Gordon en IBM y la publicación del primer texto completo dedicado a esta materia y llamado the Art of Simulation (K.D. Tocher, 1963). Estás técnicas han evolucionado de una manera extraordinaria y hoy en día están plenamente implementadas en diversos campos de actividad. Las instalaciones portuarias no han escapado de esta tendencia, especialmente las dedicadas al tráfico de contenedores. Efectivamente, las características intrínsecas de este sector económico, le hacen un candidato idóneo para la implementación de modelos de simulación con propósitos y alcances muy diversos. No existe, sin embargo y hasta lo que conocemos, un trabajo científico que compile y analice pormenorizadamente tanto la historia como la evolución de simulación en ambientes portuarios, ayudando a clasificar los mismos y determinar cómo estos pueden ayudar en el análisis económico de estas instalaciones y en la formulación de las oportunas estrategias empresariales. Este es el objetivo último de la presente tesis doctoral.[Resumo] As técnicas de simulación, tal e como hoxe as coñecemos, comezaron a mediados do século XX; primeiro coa aparición do computador e o desenvolvemento do método Monte Carlo e máis tarde co desenvolvemento do primeiro simulador de propósito específico coñecido como GPS e desenvolvido por Geoffrey Gordon en IBM e a publicación do primeiro texto completo dedicado a este tema chamado “A Arte da Simulación” (K.D. Tocher, 1963). Estas técnicas evolucionaron dun xeito extraordinario e hoxe en día están plenamente implementadas en diversos campos de actividade. As instalacións portuarias non escaparon desta tendencia, especialmente as dedicadas ao tráfico de contenedores. Efectivamente, as características intrínsecas deste sector económico, fanlle un candidato idóneo para a implementación de modelos de simulación con propósitos e alcances moi variados. Con todo, e ata o que coñecemos, non existe un traballo científico que compila e analiza de forma detallada tanto a historia como a evolución da simulación en estes ambientes portuarios, clasificando os mesmos e determinando como estes poden axudar na análise económica destas instalacións e na formulación das oportunas estratexias empresariais. Este é o último obxectivo da presente tese doutoral.[Abstract] Simulation, to the extend that we understand it nowadays, began in the middle of the 20th century; first with the appearance of the computer and the development of the Monte Carlo method, and later with the development of the first specific purpose simulator known as GPS developed by Geoffrey Gordon in IBM. This author published the first full text devoted to this subject “The Art of Simulation” in 1963. These techniques have evolved in an extraordinary way and nowadays they are fully implemented in different fields of activity. Port facilities have not escaped this trend, especially those dedicated to container traffic. Indeed, the intrinsic characteristics of this economic sector, make it a suitable candidate for the implementation of simulation with very different purposes and scope. However, to the best of our knowelegde, there is not a scientific work that compiles and analyzes in detail both, the history and the evolution of simulation in port environments, contributing to classify them and determine how they can help in the economic analysis of these facilities and in the formulation of different business strategies. This is the ultimate goal of this doctoral thesis