Jean-Christophe Deschamps

Distributed simulation platform to design advanced RFID based freight transportation systems

RFID systems, known to improve supply chains performances, are little implemented so far in industry, particularly in the field of transport, due to the high economic investment it requests in comparison to other existing solutions. However, their benefits may be theoretically proved by using a distributed simulation platform to support the design and test of any technical solution and organizational approach devoted to optimize RFID-based logistics systems. This paper deals with the development of this simulation platform, based on Generalized Discrete Event Specification (G-DEVS) models and HLA (High Level Architecture) standard. The different partners components of the networked logistics enterprise are described. The proposed solution is applied to a freight transportation system and emulates the behaviour of the various components (RFID coupled to geolocation and mobile technology) required to optimize the products routing. The behaviour of the main components is G-DEVS formalized including the logistics supplier server, the smart product and the vehicle onboard device to interface the products with a centralized server. Delivery scenarios are then elaborated and simulated to check the behaviour and the intensity of communication network use between distributed G-DEVS models and other simulation components. The strength of the approach lies in the interoperability of the platform to simulate scenarios including discrete event models, real software and hardware devices all linked via an HLA connection. From these results, a discussion is given to validate or reject the conceptual choices about logistics components behaviour and their network bandwidth requirement regarding GSM, GPRS, Bluetooth and RFID networks theoretical capacities.

Modelling and solution approaches for the interconnected city logistics

Achieving a sustainable delivery of goods in urban areas has become a challenging task for service providers and logistics managers. Under this context, the physical internet (PI) Manifesto offers through its emergent concept of interconnected city logistics (ICL) a solution toward a more sustainable transportation of PI containers within cities. In this article, we explore the operational urban transportation problem of PI containers under ICL considerations. For this variant, built on the multiplicity of urban logistics centres and their interconnection, a comprehensive modelling approach is proposed to include key features such as multiple time periods, multi-zone urban coverage, heterogeneous fleets, multi-trip and multi-hub pickups, and delivery constraints. In order to deal with solvability issues encountered with realistic instances of the problem, a heuristic solution approach is developed. This is done with the objective to come up with solutions offering the best trade-offs between economic and ecological attributes within a short computational time. To validate the approach, a realistic set of instances is built with data inspired from city freight movements in an urban area in France. Using these experiments, the solvability of the model and the performance of our heuristic approach are discussed and managerial insights are derived.

Supply chain planning under various quantity commitment contracts

Abstract This paper explores a type of supply contract under which the purchaser commits to buy a quantity of product per period with a granted flexibility over a certain horizon of time. We build a finite horizon linear programming model to characterize dynamically the production and replenishment planning depicted on each actor of the supply chain. This model based on rolling horizon planning considers gradually the emergence of new information (demand peak occurrence, disturbance on deliveries in workflow…) and takes account undergoing contractual supply constraints from the supplier. The purpose is then to investigate by numerical experimentations the impact of supply commitments contracted by partners on supply chain performance and responsiveness in order to draw some managerial insights.

How do the Key Determinants of a Distributed Planning Process Impact on the Performance of a Supply Chain

As firms search to maximise value through the effective management of their various business activities, it is increasingly important to identify and understand the key factors that can significantly impact on the performance of the supply chain. The Supply Chain Operations Reference (SCOR) model enables to identify four distinct processes (plan, source, make and deliver) that constitute a supply chain. If many researchers have studied the last three processes (source, make and deliver), the relationship between the determinants of the planning process and supply chain performance has not been sufficiently explored. This paper therefore aims to identify and analyse the determinants of a distributed planning process that impact on the performance of a supply chain, including both financial and non-financial elements. It proposes a conceptual framework and a simulation model that can be used to improve the performance of a supply chain in terms of efficiency, flexibility, effectiveness and responsiveness.

Collaborative Planning for Enterprises Involved in Different Supply Chains

This paper is to propose a generic analytic model to plan activities performed by common resources shared between different order makers. Considering the problem in a distributed and collaborative decision making context, a negotiation-based approach is proposed and systematized to express information exchanged between order makers and convergence criteria needed to rapidly calculate relevant planning solutions

Supply Chain Reactivity Assessment Regarding Two Negotiated Commitments: Frozen Horizon and Flexibility Rate

The problem addressed in this paper is the supply chain reactivity assessment through numerical experimentations regarding specifically two negotiated commitments within supply contract: the frozen horizon and flexibility rate. Analysis of impact of these commitments on each partner will be depicted in term of storage costs, reliability and reactivity indicators. The decision making inside each partner is operated under rolling horizon planning and based on production linear programming model wherein different contractual commitments are included. To carry out experimental scenarios, simulation platform is developed from which expecting numerical results afford deciders to get more understanding about the commitments that should be contracted and the relevant dimensioning of them.

Impact of the Key Determinants of a Distributed Planning Process on the Performance of a Supply Chain

In today’s highly competitive world, firms try to maximize value for their customers and other stakeholders through the effective management of their supply chains. Given that performance measurement considerably affects the actions of firms’ decision makers, it is increasingly important to understand the key factors that can significantly affect the performance of the supply chain. Using analytical models and simulations, this article aims to identify and analyse the key determinants (both financial and nonfinancial) of a distributed planning process that affect the performance of the supply chain. The identified determinants are discussed with respect to three performance dimensions: efficiency, effectiveness, and responsiveness. Our results show that different combinations of the determining factors have varying positive or negative effects on these three performance dimensions.

A Data Aggregation Methodology to Assess the Global Production Capacity of Complex Supply Chains

Nowadays, no decisional tools allow to assess if an unforeseen customers demand variation should be accepted without creating material disruptions among a supply chain or not. The main difficulty consists in aggregating resources capacities, especially if resources perform different tasks with multiple items. This paper then proposes a data aggregation methodology based on graph analysis in order to assess the global production capacity of complex resources networks, like supply chains.

MULTI-ECHELON PRODUCTION PLANNING PROCESS WITH NO TIME COORDINATION

The purpose of this paper is to study decentralized planning processes with no time coordination, performed within a whole supply chain. Distributed production and business units which compose the network, are considered as economically independent and autonomous in decision making, they define and update their production plans according to their own planning dynamic and strategy. Reactivity within these supply chains being quite dependent of this planning processes coordination, we try to assess the impact of this phenomenon on supply chain performance through a series of simulation, based on a generic linear programming model supporting the production, replenishment and delivery planning.

Decision making time assessment in multi-level periodic production management

This paper presents a comprehensive mathematical model in order to evaluate the impact of periods offset on decision making time performed in complex multi level decisional systems. The proposed approach consists in decomposing the global reaction process into several sub-processes and activities characterized by their nature and duration. Considering that decisions are periodically made, it is proved that global decision making time is related to all waiting times induced by periodic management. Reducing the reaction time consists in minimizing these waiting times. The principles of reaction processing time reduction are then illustrated by an academic example