Designing cooperation mechanisms for supply chains

The paper defines generic requirements towards cooperative planning in the nucleus of any supply network that is constituted by a pair of autonomous manufacturer and supplier who possess asymmetric information on demand forecast and costs, respectively. Then a novel way is suggested for investigating this problem by means of the apparatus of mechanism design. The analysis results in some provable generic properties as for efficiency and truthfulness, and shows the impossibility of fair cost and profit sharing. Further on, design principles towards a payment scheme are devised that provide incentive for the partners to cooperate in order to minimize costs. This payment can be considered the price for a flexible supply service. As examples, the generic framework is instantiated with two particular cooperative supply mechanisms

A distributed coordination mechanism for supply networks with asymmetric information

The paper analyses the problem of coordination in supply networks of multiple retailers and a single supplier, where partners have asymmetric, private information of demand and costs. After stating generic requirements like distributedness, truthfulness, efficiency and budget balance, we use the apparatus of mechanism design to devise a coordination mechanism that guarantees the above properties in the network. The resulting protocol is a novel realisation of the widely used Vendor Managed Inventory (VMI) where the responsibility of planning is at the supplier. We prove that together with the required generic properties a fair sharing of risks and benefits cannot be guaranteed. We illustrate the general mechanism with a detailed discussion of a specialised version, assuming that inventory planning is done according to the newsvendor model, and explore the operation of this protocol through computational experiments

Cooperative production networks - multiagent modeling and planning

Consumer goods are mainly produced in multiple steps through a long process. These steps are often done by separate, independent production nodes (enterprises), linked by supply chains. The networks of enterprises — where members have their own objectives and act in an autonomous, rational way to reach their goals — can be naturally modeled by agent-based methodology. The inner structure of each enterprise is similar in the sense that it contains separated planning functions (e.g., production-, inventory-, capacity planning). While the operation inside an enterprise can be controlled centrally, the interaction between the nodes could be synchronized only by negotiation and coordination. Coordination can be based on protocols which regulate information, material and financial flows alike. In this paper we expose an agent-based organizational model of production networks and suggest some planning algorithms which can handle the uncertainty of demand. In addition, we outline the first results of our ongoing research, an analysis of the asymmetric information case and an appropriate coordination mechanism

Online Learning for Aggregating Forecasts in Renewable Energy Systems

One of the key problems in renewable energy systems is how to model and forecast the energy flow. The paper first investigates various stochastic times-series models to predict energy production and consumption, then suggests an online learning method which adaptively aggregates the different forecasts while also taking side information into account. The approach is demonstrated on data coming from a prototype public lighting microgrid which includes photovoltaic panels and LED luminaries

Towards coordination in robust supply networks

Supply chains nowadays frequently face risks caused by increased environmental volatility and performance inefficiency In this paper an integrated supply chain planning approach is suggested that combines the three aspects of optimisation, risk mitigation and decentralisation. The goal of this paper is to outline the research directions for industrially relevant and applicable methods for integrating robust and coordinated supply chain planning. © 201

Adaptive Aggregated Predictions for Renewable Energy Systems

The paper addresses the problem of generating forecasts for energy production and consumption processes in a renewable energy system. The forecasts are made for a prototype public lighting microgrid, which includes photovoltaic panels and LED luminaries that regulate their lighting levels, as inputs for a receding horizon controller. Several stochastic models are fitted to historical times-series data and it is argued that side information, such as clear-sky predictions or the typical system behavior, can be used as exogenous inputs to increase their performance. The predictions can be further improved by combining the forecasts of several models using online learning, the framework of prediction with expert advice. The paper suggests an adaptive aggregation method which also takes side information into account, and makes a state-dependent aggregation. Numerical experiments are presented, as well, showing the efficiency of the estimated timeseries models and the proposed aggregation approach

Prediction and Robust Control of Energy Flow in Renewable Energy Systems

The paper is motivated by making use of solar energy in public lighting services via an intermediate battery storage. The aim is to develop algorithms for controlling the energy flow in the system, in such a way that robustness against power outages is guaranteed and the total energy cost is minimized. A novel approach is proposed which predicts energy production and consumption by fitting stochastic models to historic data, and solves the resulting optimization problem on a rolling horizon. Experimental results are also presented, illustrating the behavior of the controlled energy system in typical winter and summer days

Új projekt ütemezési módszerek a termelés-tervezés támogatására = New project scheduling approaches for production planning

Munkákat az motiválta, hogy az általános erőforrás-korlátos projekt ütemezési probléma olyan új modelljeit és megoldási módszereit dolgozzuk ki, melyek megfelelnek a termelés-tervezés és -ütemezés aktuális, ipari gyakorlat által is támasztott követelményeinek. A kutatás során a következő fő eredményeket értük el: 1. Új modelleket és megoldó algoritmusokat dolgoztunk ki a változó intenzitású tevékenységekkel történő erőforrás-korlátos projekt ütemezés témájában. 2. Nagyméretű korlátozás programozási és korlátozás-alapú ütemezési feladatok megoldására dolgoztunk ki olyan általános módszereket, melyek kihasználva a gyakorlati feladatokra jellemző strukturális sajátosságokat jelentősen növelik a megoldó hatékonyságát. 3. A fenti modellek és megoldó módszerek alkalmazásával megvalósítottunk egy közös modellen alapuló, ám a részletezettség (ún. aggregáltság) eltérő szintjein működő hierarchikus termeléstervező és -ütemező rendszert. 4. A termeléstervezés és -ütemezés terén elért eredményeket termelési hálózatokra is kiterjesztettük: autonóm gyártó és beszállító felek közt működő kooperatív tervezési modellt dolgoztunk ki, amely biztosítja a gyártó anyagellátását. | Our research was focused on advanced production planning and scheduling models and methods that were able to meet real industrial requirements. This called for generic resource-constrained project scheduling models with strong representative power on the hand, and efficient solution techniques on the other hand. 1. We have developed a novel approach to modeling and solving production planning problems that unifies the capacity and the material flow oriented aspects of planning. Orders are modeled as projects comprising of networks of variable-intensity activities that compete for limited resources. 2. For solving detailed production scheduling problems we have taken a constraint programming approach and developed new methods that exploit the hidden structural properties of large, real-life job-shop scheduling problems. It was proven that these methods reduced the search space drastically and improved the performance of constraint solvers. 3. Based on the above results, we developed a pilot production planner and scheduler system. The planning and scheduling levels are integrated by a new aggregation method that warrants for the executability of high-level production plans on the detailed level of scheduling. 4. The results in production planning and scheduling were extended to the management of production networks, where a cooperative customer-supplier planning model has been elaborated for supporting material supply at the lowest possible costs