Scheduling and Control Modelling of HVLV Systems Using Max-Plus Algebra

International audienceThe High-Variety, Low-Volume (HVLV) scheduling problem is one of the most arduous and combinatorial optimization problems. This paper presents an analytical scheduling model using a tropical algebra called (max,+) algebra. The aim is to find an allocation for each operation and to define the sequence of operations on each machine, so that the resulting schedule has a minimal completion time and the due dates of the different jobs (products) are met such that a Just-In-Time (JIT) production will be satisfied. To generate feasible schedules, decision variables are introduced in the model. The algebraic model developed in this work describes the discontinuous operations aspect of HVLV systems as Discrete Event Dynamic Systems (DEDS). It is non-linear in the sense of (max,+) algebra. The focus of this research concerns the development of a static scheduling approach for deterministic and not-decision-free HVLV manufacturing systems. Firstly, using (max, +) algebra, a direct generation of event-timing equations for deterministic and not-decision free HVLV systems is obtained. Then, a non-linear optimization problem in (max, +) algebra is solved. Finally, the validity of the proposed approach is illustrated by simulation examples

A conceptual model for SMEs mechatronics supply chain.

17International audienceNowadays, in order to meet the demands of the global dynamic market and eliminate its disturbances, the supply chain and its integration across different organizations has become a competitive business advantage along the production processes. In particular, the mechatronic industry is very sensitive to these requirements. Our research deals with modelling the supply chain in order to manage and implement a simulation platform. Basically, we develop a modelling solution for an industrial environment composed of mechatronic Small and Medium Enterprises located in Savoie (France). The study is based on elements from real applications and the SMEs network organization. An analysis of the domain helped us to develop concepts and a modelling approach adapted to these companies. In this work, we present the area studied, the methodology used to construct the conceptual model of the supply chain, its structure and management rules. Then, we present the model obtained. Finally, we apply this conceptual model to a case study

Application of a continuous supervisory fuzzy control on a discrete scheduling of manufacturing systems.

10 pagesInternational audienceThis paper considers the modelling and simulation of a hierarchical production-flow control system. Particularly, the system capacity allocation has been addressed by a set of distributed and supervised fuzzy controllers. The objective is to adjust the machine's production rates in such a way that satisfies the demand while maintaining the overall performances within acceptable limits. Given the adjusted production rates, the problem of scheduling of jobs is considered at the shop-floor level. In this case, the actual dispatching times are determined from the continuous production rates through a sampling procedure. To deal with conflicts between jobs at a shared machine, a decision for the actual part to be processed is taken using some criteria which represent a measure of the job's priority. A case study demonstrates the efficiency of the proposed control approach

Pilotage Flou Distribué et Supervisé pour la Régulation des Flux de Production

National audienceDans cet article, une structure de pilotage distribuée et supervisée pour la régulation des flux de production est proposée. Partant de la décomposition d'un système de production en un ensemble de modules élémentaires, une structure de pilotage distribuée de type multi-contrôleurs est déployée au niveau " local ". A ce niveau, chaque module de production est piloté par un contrôleur flou afin de satisfaire la demande et d'éviter les phénomènes de rupture et de blocage. Afin d'améliorer les performances de cette structure, un niveau de supervision est intégré. Ce dernier a pour rôle de coordonner les actions locales et de réaliser des compromis entre les objectifs globaux. La conception du superviseur s'appuie sur l'exploitation des opérateurs d'agrégation et la quantification des objectifs par des intervalles flous. Un exemple de simulation est considéré pour illustrer les performances de la méthodologie proposée

A propos de la modélisation et le pilotage des systèmes manufacturiers de type HVLV

International audienceIl s'agit dans ce papier de développer un modèle d'ordonnancement basé sur des méthodes analytiques permettant la simulation à évènements discrets des systèmes de production assez complexes de type HVLV (High Variety, Low Volume), dont la date de besoin client est un paramètre important, afin de converger plus rapidement vers des solutions quasi-optimales ou optimales

Une Approche Agent pour Modéliser la Chaîne Logistique dans un Contexte de PME Mécatronique

International audienceFace aux exigences du marché et à ses fréquentes mutations, l'intégration des différents acteurs dans la chaîne logistique est devenue un atout concurrentiel quel que soit le domaine de production, qu'il soit de biens ou de services. Le domaine de la mécatronique n'est pas épargné par ces exigences. Les travaux de recherche présentés dans cet article s'inscrivent dans ce domaine puisqu'ils s'orientent vers la recherche d'une solution pour un tissu industriel composé particulièrement de PME situées dans les pays de Savoie. Dans cet article, nous mettons en œuvre des recherches issues de deux domaines différents. Le premier se focalise sur l'étude des maillons et de l'organisation des PME dans la chaîne logistique. L'analyse qui en découle nous permet d'identifier et de modéliser les concepts relatifs à notre domaine de recherche. Le second concerne le processus de développement logiciel basé sur l'approche multiagent qui offre une modélisation structurée et réutilisable des concepts de la chaîne logistique. Abstract - In order to meet global dynamic market and its perturbations, the supply chain and its integration across the different organizations has become a competitive business advantage along the production processes. In particular, the mechatronic industry is very sensitive to these requirements. Our research deals with a supply chain modelling solution for an industrial environment composed of Small and Medium mechatronic Enterprises located in Savoy. In this paper, we combine two research scopes. The first one focuses on the study of elements and SME organization in the supply chain. The analysis allows us to identify and model the research domain concepts. The second one outlines the development process based on an agent modelling approach which offers an easy and reusable modelling of supply chain concepts

Multiagent Decision Making for SME Supply Chain Simulation

International audienceTo tackle the complexity and heterogeneity of the networks that integrate Mechatronic SMEs, this paper describes a modelling and simulation solution based on multiagent system and ArchMDE (Architecture Model Drive Engineering) methodology for supply chain agentification. This research work outlines two main results: conceptualisation and modelling. The first one deals with the identification and concepts definition of the different entities moving and acting into the multiagent and supply chain systems. The second one discusses the agent approach providing a framework naturally oriented to model supply chain concepts and their dynamic behavior

A Multiagent System for Production Synchronization in SME Mecatronics Supply Chain

International audienceWe present in this paper the application of multiagent system (MAS) for modelling and simulation of the dynamic structure and behaviour of the supply chain in SMEs mechatronic context in Savoie. First, a short literature overview describes the context and the contribution of multiagent modelling for SMEs integration. In the rest of the paper, the supply chain concepts and their agentification are presented. On the basis of this correspondence, we propose a synchronization protocol for the operational system (production flow and resources)

A Mathematical Model for HVLV Systems Scheduling and Optimization With Periodic Preventive Maintenance Using (max, +) Algebra

International audienceThe High-Variety, Low-Volume (HVLV) scheduling problem is one of the most arduous combinatorial optimization problems. This paper considers an interesting formulation of the HVLV scheduling problem using (max, +) algebra while periodic Preventive Maintenance (PM) is considered. Maintenance is time based since activities are periodically fixed: maintenance is required after a periodic time interval (all periods are equals on each machine). In this paper, the maintenance tasks of machines are controllable.The jobs and the maintenance operations are scheduled simultaneously. Also, the maintenance operations are scheduled between each other, so that a regular criterion is optimized. To generate feasible schedules, constrained decision variables are incorporated into the (max, +) model. The validity of the proposed approach is illustrated by simulation examples

Max-plus-linear model-based predictive control for constrained HVLV manufacturing systems

International audienceIn this paper, a max-plus-linear model predictive con- trol strategy is proposed for High-Variety, Low-Volume (HVLV) systems. Firstly, using the (max,+) algebra, a di- rect generation of event-timing equations for determinis- tic and decision-free HVLV manufacturing systems is ob- tained. Then, a linear optimization method is presented. It is based on canonical forms for Max-Min-Plus-Scaling (MMPS) functions with linear constraints on the inputs. The approach aims at solving several linear programming problems and its validity is illustrated by a simulation ex- ample. Finally, a discussion of results, conclusions and perspectives are given