Agile MPC system linking manufacturing and market strategies

Increasing complexity and interdependency in manufacturing enterprises require an agile manufacturing paradigm. This paper considers a dynamic control approach for linking manufacturing strategy with market strategy through a reconfigurable manufacturing planning and control (MPC) system to support agility in this context. A comprehensive MPC model capable of adopting different MPC strategies through distributed controllers of inventory, capacity, and WIP is presented. A hierarchical supervisory controller (referred to as decision logic unit, DLU) that intakes the high-level strategic market decisions and constraints together with feedback of the current manufacturing system state (WIP, production, and inventory levels) and optimally manages the distributed controllers is introduced. The DLU architecture with its three layers and their different functionalities is discussed showing how they link the higher management level to the operational level to satisfy the required demand. A case study for an automatic PCB assembly factory is implemented to demonstrate the applicability of the whole approach. In addition, a comparative cost analysis study is carried out to compare between the developed agile MPC system and classical-inventory- and capacity-based MPC policies in response to different demand patterns. Results showed that the developed agile MPC policy is as cost effective as the inventory-based MPC policy in demand patterns with steady trends, as cost effective as capacity-based MPC in turbulent demand patterns, and far superior than both classical MPC polices in mixed-demand patterns

How environment dynamics affects production scheduling: requirements for development of CPPS models

Production scheduling can be affected by many disturbances in the manufacturing system, and consequently, the feasible schedules previously defined became obsolete. Emerging of new technologies associated with Industry 4.0, such as Cyber-Physical Production Systems, as a paradigm of implementation of control and support in decision making, should embed the capacity to simulate different environment scenarios based on the data collected by the manufacturing systems. This paper presents the evaluation of environment dynamics effect on production scheduling, considering three scheduling models and three environment scenarios, through a case study. Results show that environment dynamics affect production schedules, and a very strong or strong positive correlation between environment dynamics scenarios and total completion time with delay, over three scheduling paradigms. Based on these results, the requirement for mandatory inclusion of a module for different environment dynamics scenarios generation and the corresponded simulations, of a Cyber-Physical Production Systems architecture, is confirmed.This work has been supported by FCT -Fundacao para a Ciencia e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020

Self-organized critical & complex adaptive systems in a simulated manufacturing environment

The application of this thesis compares three different manufacturing theories, varying on resource allocation, to decide which performs best. Three Resource Allocation methods are analyzed including a static resource allocation method, a semidynamic resource allocation method, and a dynamic resource allocation method. The last methodology used in this thesis develops a resource allocation method intended to display complex behavior. A Base Case manufacturing simulation is developed to represent a static resource allocation system. A Theory of Constraints manufacturing model using the Theory of Constraints process represents a semi-dynamic resource allocation system. A Complex Adaptive System manufacturing model using autonomous agents represents a dynamic resource allocation system. The systems were analyzed at multiple stress levels for system to system performance, as well as for complex behavior. Dynamic resource allocation outperformed the semi-dynamic allocation and static allocation systems unilaterally. Some complex behavior was displayed for elements of some models, but as a whole, a trend of increasing complexity did not emerge as the models were analyzed from the Base Case, to Theory of Constraints, to the Complex Adaptive System

Réduction du comportement myope dans le contrôle des FMS : une approche semi-hétérarchique basée sur la simulation-optimisation

Heterarchical-based control for flexible manufacturing systems (FMS) localizes control capabilities in decisional entities (DE), resulting in highly reactive and low complex control architectures. However, these architectures present myopic behavior since DEs have limited visibility of other DEs and their behavior, making difficult to ensure certain global performance. This dissertation focuses on reducing myopic behavior. At first, a definition and a typology of myopic behavior in FMS is proposed. In this thesis, myopic behavior is dealt explicitly so global performance can be improved. Thus, we propose a semi-heterarchical architecture in which a global decisional entity (GDE) deals with different kinds of myopic decisions using simulation-based optimization (SbOs). Different optimization techniques can be used so myopic decisions can be dealt individually, favoring GDE modularity. Then, the SbOs can adopt different roles, being possible to reduce myopic behavior in different ways. More, it is also possible to grant local decisional entities with different autonomy levels by applying different interaction modes. In order to balance reactivity and global performance, our approach accepts configurations in which some myopic behaviors are reduced and others are accepted. Our approach was instantiated to control the assembly cell at Valenciennes AIPPRIMECA center. Simulation results showed that the proposed architecture reduces myopic behavior whereby it strikes a balance between reactivity and global performance. The real implementation on the assembly cell verified the effectiveness of our approach under realistic dynamic scenarios, and promising results were obtained.Le contrôle hétérarchique des systèmes de production flexibles (FMS) préconise un contrôle peu complexe et hautement réactif supporté par des entités décisionnelles locales (DEs). En dépit d'avancées prometteuses, ces architectures présentent un comportement myope car les DEs ont une visibilité informationnelle limitée sue les autres DEs, ce qui rend difficile la garantie d'une performance globale minimum. Cette thèse se concentre sur les approches permettant de réduire cette myopie. D'abord, une définition et une typologie de cette myopie dans les FMS sont proposées. Ensuite, nous proposons de traiter explicitement le comportement myope avec une architecture semi-hétérarchique. Dans celle-ci, une entité décisionnelle globale (GDE) traite différents types de décisions myopes à l'aide des différentes techniques d'optimisation basée sur la simulation (SbO). De plus, les SbO peuvent adopter plusieurs rôles, permettant de réduire le comportement myope de plusieurs façons. Il est également possible d'avoir plusieurs niveaux d'autonomie en appliquant différents modes d'interaction. Ainsi, notre approche accepte des configurations dans lesquelles certains comportements myopes sont réduits et d'autres sont acceptés. Notre approche a été instanciée pour contrôler la cellule flexible AIP- PRIMECA de l'Université de Valenciennes. Les résultats des simulations ont montré que l'architecture proposée peut réduire les comportements myopes en établissant un équilibre entre la réactivité et la performance globale. Des expérimentations réelles ont été réalisées sur la cellule AIP-PRIMECA pour des scenarios dynamiques et des résultats prometteurs ont été obtenus

An agent-based approach for tourist planning

El turismo se comporta como un sistema complejo en evolución dinámica, que abarca numerosos factores y actividades que son interdependientes y cuyas relaciones pueden ser altamente no lineales (Baggio, 2008). Los sistemas de recomendación y los planificadores de rutas se utilizan con frecuencia para filtrar información que no es importante y, a su vez, ofrecen un servicio personalizado para los turistas (Noguera et. Al 2012). En este contexto, los modelos basados en agentes (ABM) son una herramienta apropiada para la toma de decisiones porque permiten representar sistemas complejos o situaciones con agentes autónomos en un escenario establecido (Nicholls et. Al, 2017). Además, ABM tiene la capacidad de modelar fenómenos emergentes, por lo tanto, fenómenos como las normas culturales que surgen en la sociedad debido a las interacciones entre los individuos y otros agentes, a veces incluso de manera contradictoria, y que no son bien captados por las técnicas de modelado tradicionales ( Nicholls et. Al., 2017). En esta perspectiva, este proyecto propone un ABM para simular el turismo en Bogotá. El objetivo principal es apoyar al turista en la planificación y realización de diferentes actividades turísticas, considerando variables cualitativas y cuantitativas que maximicen la experiencia de un turista que visita Bogotá (Colombia), que a su vez puede contribuir al desarrollo de este sector económico.Tourism behaves as a dynamic evolving complex system, encompassing numerous factors and activities that are interdependent and whose relationships might be highly nonlinear (Baggio, 2008). Recommendation systems and route planners are frequently used to filter information that is not important and in turn offer a personalized service for tourists (Noguera et. al 2012). In this context, Agent-Based Models (ABM) are an appropriate tool for decision making because they allow representing complex systems or situations with autonomous agents in an established scenario (Nicholls et. al, 2017). In addition, ABM has an ability for modeling emergent phenomena, thus phenomena such as cultural norms that come up into society because of interactions between individuals and other agents, sometimes even in a counterintuitive manner, and that are not well captured by traditional modeling techniques (Nicholls et. al, 2017). In this perspective, this project proposes an ABM to simulate tourism in Bogota. The main objetictive is to support the tourist in the planning and realization of different tourism activities, considering qualitative and quantitative variables that maximize the experience of a tourist visitingBogota (Colombia), which in turn may contribute to the development of this economic sector. In general, the results in several scenarios are positive according to the average level of satisfaction obtained, which means that the recommendations generated by the application are adequate. Therefore, the model has the potential to help current tourism platforms to better accomplish satisfactory recommendations for tourists and even be the basis for the development of a new app, so this would allow promoting the growth of tourism in La Candelaria, Bogota.Ingeniero (a) IndustrialPregrad

Dynamic models for production control and scheduling.

Agility may be an important competitive advantage in many markets. In order to achieve it, the dynamics of the manufacturing systems must be considered. Control theory supports the development of dynamic models for production and inventory control. This paper discusses some dynamic models of production control specifically applied to scheduling \ud and shop floor control. A comparative and critical analysis of the models is presented and directions for future works are provided

Proposition d’une architecture holonique auto-organisée et évolutive pour le pilotage des systèmes de production

The manufacturing world is being deeply challenged with a set of ever demanding constraints where from one side, the costumers are requiring products to be more customizable, with higher quality at lower prices, and on other side, companies have to deal on a daily basis with internal disturbances that range from machine breakdown to worker absence and from demand fluctuation to frequent production changes. This dissertation proposes a manufacturing control architecture, following the holonic principles developed in the ADAptive holonic COntrol aRchitecture (ADACOR) and extending it taking inspiration in evolutionary theories and making use of self- organization mechanisms. The use of evolutionary theories enrich the proposed control architecture by allowing evolution in two distinct ways, responding accordingly to the type and degree of the disturbance that appears. The first component, named behavioural self- organization, allows each system’s entity to dynamically adapt its internal behaviour, addressing small disturbances. The second component, named structural self-organization, addresses bigger disturbances by allowing the system entities to re-arrange their rela- tionships, and consequently changing the system in a structural manner. The proposed self-organized holonic manufacturing control architecture was validated at a AIP-PRIMECA flexible manufacturing cell. The achieved experimental results have also shown an improvement of the key performance indicators over the hierarchical and heterarchical control architecture.Le monde des entreprises est profondément soumis à un ensemble de contraintes toujours plus exigeantes provenant d’une part des clients, exigeant des produits plus personnalisables, de qualité supérieure et à faible coût, et d’autre part des aléas internes auxentreprises, comprenant les pannes machines, les défaillances humaines, la fluctuation de la demande, les fréquentes variations de production. Cette thèse propose une architecture de contrôle de systèmes de production, basée sur les principes holoniques développées dans l’architecture ADACOR (ADAptive holonic COntrol aRchitecture), et l’étendant en s’inspirant des théories de l’évolution et en utilisant des mécanismes d’auto-organisation. L’utilisation des théories de l’évolution enrichit l’architecture de contrôle en permettant l’évolution de deux manières distinctes, en réponse au type et au degré de la perturbation apparue. Le premier mode d’adaptation, appelé auto-organisation comportementale, permet à chaque entité qui compose le système d’adapter dynamiquement leur comportement interne, gérant de cette façon de petites perturbations. Le second mode, nommé auto-organisation structurelle, traite de plus grandes perturbations, en permettant aux entités du système de ré-organiser leurs relations, et par conséquent modifier structurellement le système. L’architecture holonique auto-organisée de contrôle de systèmes de production proposée dans cette thèse a été validée sur une cellule de production flexible AIP-PRIMECA. Les résultats ont montré une amélioration des indicateurs clés de performance par rapport aux architectures de contrôle hiérarchiques et hétérarchiques