René Haijema

René Haijema
Wageningen University & Research | WUR · Operations Research and Logistics Group

PhD

About

91
Publications
13,853
Reads
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1,870
Citations
Additional affiliations
September 2015 - present
Wageningen University & Research
Position
  • Professor (Associate)
September 2007 - August 2015
Wageningen University & Research
Position
  • Professor (Assistant)
September 2002 - September 2007
University of Amsterdam
Position
  • Lecturer + PhD research

Publications

Publications (91)
Article
This paper presents a solution approach to the joint assortment and inventory planning problem for vertically differentiated products considering dynamic consumer-driven substitution. The demand for each product and the stockout-based substitution rates are derived from a consumer’s utility function and a random market size. We propose a two-step i...
Article
Full-text available
Retailers can exploit the consumer willingness to substitute to improve their profit, service level and waste. This paper investigates to what extent such improvement can be realised by the replenishment decisions. Two order policies are compared: one policy neglecting product substitution, and a new policy that decides on order quantities for all...
Article
Full-text available
As a large part of world food production spoils/expires before consumption, reduction of food waste by optimizing order policies in retail is of importance. We sketch here the computational burden of trying to obtain the optimal order quantities with the process of Value Iteration for a retailer situation with highly perishable products. It appears...
Article
Full-text available
In retail, it is usual to measure the performance of inventory control by a so-called service level which measures the number of days (probability) that demand is fulfilled for a certain product, i.e. the product is not out of stock. Part of the customers that do not encounter the product in stock will look for a substitute. To measure the performa...
Article
Full-text available
The food industry is confronted with a pressure to reduce waste and to make agreements on donating surplus food to charitable organizations. Charitable organizations such as food banks and soup kitchens can use these donations in preparing food parcels or meals for their clients. For soup kitchens, donation management is strongly influencing menu p...
Article
Many supermarkets and retailers use computer assisted ordering (CAO) or automated order systems (ASO) to determine replenishment quantities. Traditionally, these systems are designed for non-perishables, and order quantities are set by (modified) base stock policies, determined according to the total number of units in stock, regardless of the ages...
Article
Full-text available
In the fresh produce wholesale market, the market price is determined by the total demand and supply. The price is stochastic, and either wholesaler or retailer has few influence on it. In the wholesaler’s inventory decision, the price’s uncertainty plays an important role as well as the uncertainty from the demand side: the wholesaler makes his de...
Article
Traditional wholesalers of fresh produce in China display and sell all the products that they have brought to the wholesale market every day. Products left by the end of the day are deteriorated due to high temperatures at which products are displayed, and are thus sold at a low price or disposed. Modern wholesalers can preserve product quality and...
Article
Approximately 89 million of tonnes of food is wasted every year in the EU along the whole food supply chain. The reasons for food waste by retailers include inappropriate quality control, overstocking and inaccurate forecasting. This study shows that food wasted by retailers can be reduced by discounting old products or by applying a dynamically ad...
Article
Full-text available
Management objectives of the European Union for North Sea fish stocks are shifting towards considering both biological sustainability and economic benefits. As part of multiannual management plans, an adjustment restriction on fish quota has been introduced. Its objective is to obtain an efficient fish stock and to reduce overcapacity for the fishi...
Chapter
Traffic lights are put in place to dynamically change priority between traffic participants. Commonly, the duration of green intervals and the grouping, and ordering in which traffic flows are served are pre-fixed. In this chapter, the problem of minimizing vehicle delay at isolated intersections is formulated as a Markov Decision Process (MDP). So...
Chapter
This paper illustrates how MDP or Stochastic Dynamic Programming (SDP) can be used in practice for blood management at blood banks; both to set regular production quantities for perishable blood products (platelets) and how to do so in irregular periods (as holidays). The state space is too large to solve most practical problems using SDP. Neverthe...
Chapter
This paper describes and analyses a bi-level Markov Decision Problem (MDP). The model has been used to study questions on the setting of fisheries quota. The problem extends earlier models in literature and describes fish stock and economic dynamics. At the first level, an authority decides on the quota to be fished keeping in mind long term revenu...
Article
The duration of logistics operations, as well as the environmental conditions during these operations, significantly impact the performance of a logistics network for fresh agricultural products. When durations or temperatures increase, product quality decreases and more effort is required to deliver products in time and with the right quality. Dif...
Article
The objective of this paper is to develop a systematic overview of interventions for preventing chilled-food waste at retail outlets, and to assess the impact of these interventions for a particular case of fresh-cut iceberg lettuce at a Dutch retail outlet. The structure of the simulation model as presented in this paper is generic, hence suitable...
Conference Paper
Full-text available
Climate control is essential for managing the production of horticulture in greenhouses. One of the traditional ways to control the climate in the greenhouse is Model Predictive Control (MPC). This paper studies the potential of using branch and bound algorithms in order to effectively reach the best control in MPC.
Article
Full-text available
Management objectives of the European Union for North Sea fish stocks are shifting towards considering both biological sustainability and economic benefits. As part of multiannual management plans, an adjustment restriction on fish quota has been introduced. Its objective is to obtain an efficient fish stock and to reduce overcapacity for the fishi...
Chapter
Today’s business environment and harsh competitiveness force companies and entire supply chains to increase their efficiency as much as possible. As a consequence, supply chains have become highly sensitive to disruptions and less tolerant to deviations in operations, that is, supply chains have become more vulnerable (see Kleindorfer and Saad, 200...
Article
Full-text available
Climate control is essential for managing the production of horticulture in greenhouses. One of the traditional ways to control the climate in the greenhouse is Model Predictive Control (MPC). This paper studies the potential of using branch and bound algorithms in order to effectively reach the best control in MPC.
Article
We study the practical decision problem of fresh food production with a long production lead time to decide every period (e.g. week) how many items to produce. When a batch is ready for use, its items have a fixed shelf life, after which the items become waste in the sense that they cannot be sold anymore. The demand for (fresh) food products is un...
Article
In practice, traditional stock-level dependent policies, like base-stock policies (BSP) and constant order policies (COP), are commonly used for replenishing inventories of perishable products at retailers. These policies are preferred for being easy to implement: they only require information on the total number of products in stock, but not diffe...
Conference Paper
This paper studies the computation of so-called order-up-to levels for a stochastic programming inventory problem of a perishable product. Finding a solution is a challenge as the problem enhances a perishable product, fixed ordering cost and non-stationary stochastic demand with a service level constraint. An earlier study [7] derived order-up-to...
Article
Full-text available
The floricultural sector is facing market developments that have forced a redesign of the European logistics network. Via workshops and interviews with key stakeholders the main developments and industry needs are identified. These are then summarised in three central themes that require further investigation, i.e. decision problems (e.g. network d...
Article
The floricultural sector is facing market developments that have forced a redesign of the European logistics network. Via workshops and interviews with key stakeholders the main developments and industry needs are identified. These are then summarised in three central themes that require further investigation, i.e. decision problems (e.g. network d...
Article
Perishables, such as packed fresh food and pharmaceutical products (a.o. blood products), typically have a fixed shelf life set by a fixed use-by date or sell-by date. Despite their limited life time, orders in practice are usually based on the stock level irrespective of the ages of the products in stock. The management of inventories of such prod...
Conference Paper
Full-text available
Los semáforos se pueden controlar de forma dinámica a través de varias reglas que dictaminan el color del semáforo según el número de vehículos a la espera. Estas reglas o acciones se recogen en lo que se conoce como una Tabla de Control de Tráfico (TCT). Se ha calculado una TCT óptima sólo para infraestructuras simples mediante el método de Iterac...
Conference Paper
Full-text available
We study the global optimal solution for a planning problem of inventory control of perishable products and non-stationary demand.
Conference Paper
Traffic lights can be controlled dynamically through rules reacting on the number of waiting vehicles at each light. A rule can be captured by a so-called Traffic Control Table (TCT). The Value Iteration method from Stochastic Dynamic Programming has been used for simple networks to derive a TCT. This work studies the generation of a TCT-based rule...
Article
Stochastic dynamic programming (SDP) is a useful tool for analyzing policy questions in fisheries management. In order to understand and reproduce solution procedures such as value function iteration, an analytic elaboration of the problem and model characteristics is required. Because of the increased use of numerical techniques, our aim is to imp...
Article
North Sea fisheries are managed by the European Union (EU) through a system of annual quota. Due to uncertainty about future fish stocks, yearly revisions of these policies lead to fluctuation in quota, which in turn affects harvest and investment decisions of fishermen. Determination of quota requires high management costs in terms of obtaining in...
Article
Many perishables such as fresh food and blood platelet concentrates are characterized by a short maximum shelf life. As demand is often highly uncertain the outdating and shortages figures can be very high, especially when frequent replenishment is not possible or inefficient due to fixed ordering cost. We present a new class of stock-level depende...
Article
The dynamic adaptive control of traffic lights can be formulated as a Markov decision problem (MDP). This framework is hardly used, as solving an MDP can be very time-consuming and is only possible for simple infrastructures with a small number of traffic flows. Nevertheless, we show that the MDP framework can be used to construct control policies...
Article
Full-text available
The basis of this study is a Stochastic Programming (SP) model derived for a practical case of a specifc inventory control problem for a perishable product. As it contains chance constraints describing the service level, deriving policies for this model is a challenge. In order to find parameter values in an order-up-to level policy, we derive a co...
Article
Full-text available
We study the practical production planning problem of a food producer facing a non-stationary erratic demand for a perishable product with a fixed life time. In meeting the uncertain demand, the food producer uses a FIFO issuing policy. The food producer aims at meeting a certain service level at lowest cost. Every production run a set-up cost is i...
Conference Paper
This paper discusses and typifies logistics decision making in a highly complex system, namely an international fresh product supply chain network. Taking the floricultural sector as example case, we develop a conceptual model that incorporates the important system characteristics (e.g. network design, inventories), context factors (e.g. demand and...
Conference Paper
Full-text available
Simulation is known to be a powerful technique to analyze the dynamic behavior of a variety of systems. Dynamic programming is a technique to solve sequential decision making problems. The numerical solution of a dynamic program is a table with an optimal decision for all feasible states of the system. Such a table is usually complex as it lists al...
Conference Paper
Full-text available
This paper describes and analyses a Stochastic Programming (SP) model that is used for a specific inventory control problem for a per-ishable product. The decision maker is confronted with a non-stationary random demand for a fixed shelf life product and wants to make an or-dering plan for a finite horizon that satisfies a service level constraint....
Article
Full-text available
After years of emphasis on leanness and responsiveness businesses are now experiencing their vulnerability to supply chain disturbances. Although more literature is appearing on this subject, there is a need for an integrated framework to support the analysis and design of robust food supply chains. In this paper we present such a framework. We def...
Article
Full-text available
High effectiveness and leanness of modern supply chains (SCs) increase their vulnerability, i.e. susceptibility to disturbances reflected in non-robust SC performances. Both the SC management literature and SC professionals indicate the need for the development of SC vulnerability assessment tools. In this article, a new method for vulnerability as...
Article
North Sea fisheries are management by the European Union (EU) through a system of annual quota. Due to uncertainty about future fish stocks, yearly revisions of these policies lead to fluctuation in quota, which in turn affects harvest and investment decisions of fishermen.
Article
Full-text available
Stochastic dynamic programming (SDP) is a useful tool for analyzing policy questions in fisheries management. In order to understand and reproduce solution procedures such as value function iteration, an analytic elaboration of the problem and model characteristics is required.
Conference Paper
The management of inventories of perishable products with a short maximal shelf life takes a good issuing policy next to a good ordering policy. Ordering policies of non-perishables are well studied in literature and implemented in Automated Store Ordering (ASO) systems and Computer Assisted Ordering (CAO) systems. These ordering policies are stock...
Article
Full-text available
The concept of traffic control tables (TCT) for an intersection is sketched and a Stochastic Dynamic Programming model is outlined. The determination of a TCT by dynamic programming becomes more cumbersome if more traffic flows and combination of lights are taken into account. This paper explains how High Performance Computing (HPC) can be essentia...
Conference Paper
Efficient supply chains are vulnerable to unexpected changes in realization of logistic and production processes. This vulnerability is manifested as sudden hiccups or surges in chain's performance values. Objective of the companies is to have robust performances. In this paper we show that it is possible to achieve supply chain robustness, or at l...
Conference Paper
After years of emphasis on leanness and responsiveness businesses are now experiencing their vulnerability to supply chain disturbances. Although more literature is appearing on this subject, there is a need for an integrated framework to support the analysis and design of robust food supply chains. In this paper we present such a framework. We def...
Article
The production and inventory management of blood products at blood banks and hospitals is a problem of general human interest. As a shortage may put lives at risk, shortages are to be kept to a minimum. As the supply is voluntary and costly, any spill of unused blood (products) is also to be minimized. Blood platelets (thrombocytes), which are the...
Article
The challenge of production and inventory management for blood platelets (PLTs) is the requirement to meet highly uncertain demands. Shortages are to be minimized, if not to be avoided at all. Overproduction, in turn, leads to high levels of outdating as PLTs have a limited "shelf life." Outdating is to be minimized for ethical and cost reasons. Op...
Article
This chapter aims to promote and illustrate the fruitful combination of classical operations research (OR) and computer simulation. First, a highly instructive example of parallel queues will be studied. This simple example already shows the necessary combination of OR (queueing) and simulation that appears to be of practical interest such as for c...
Article
This article presents a novel approach for the dynamic control of a signalized intersection. At the intersection, there is a number of arrival flows of cars, each having a single queue (lane). The set of all flows is partitioned into disjoint combinations of nonconflicting flows that will receive green together. The dynamic control of the traffic l...
Article
Blood platelets are precious, as voluntarily supplied by donors, and highly perishable, with limited lifetimes of 5–7 days. Demand is highly variable and uncertain. A practical production and inventory rule is strived for that minimizes shortages and spill. The demand and production are periodic, as varying over the seven days of the week. Demand f...
Article
Blood platelets are precious, as voluntarily supplied by donors, and highly perishable, with limited lifetimes of 5¿7 days. Demand is highly variable and uncertain. A practical production and inventory rule is strived for that minimizes shortages and spill. The demand and production are periodic, as varying over the seven days of the week. Demand f...
Chapter
This chapter describes a practical approach for the train-shunting problem. Solving the shunting problem is a daily difficult job for planners. This chapter reports on a practical train-shunting heuristic that shows similarities with Dynamic Programming (DP).
Conference Paper
Full-text available
Should we pool capacities or not? This is a question that one can regularly be confronted with in operations and service management. It is a question that necessarily requires a combination of queueing (as OR discipline) and simulation (as evaluative tool) and further steps for optimization. It was illustrated that a combined approach (SimOR) of si...
Chapter
Blood banks produce and store blood products in order to fulfil the uncertain demand at hospitals. Platelet pools are the most expensive and most perishable blood product having a shelf life of only four to six days. Production volumes need to be chosen carefully in order to reduce outdating while keeping the occurrence of shortages low. We invest...