Nico Vandaele

KU Leuven | ku leuven · Research Centre for Operations Management

Dialogue with people who are vaccine hesitant has been recommended as a method to increase vaccination uptake. The process of cultivating dialogue is shaped by the context in which it occurs, yet the development of interventions addressing vaccine hesitancy with dialogue often overlooks the role of context and favors relatively fixed solutions. Thi...

Despite the increased importance attributed to distributed improvisation in major crises, few studies investigate how central authorities can promote a harmonic, coordinated national response while allowing for distributed autonomy and improvisation. One idea implicit in the literature is that central authorities could help track and tackle common...

Background Polarized debates about Covid-19 vaccination and vaccine mandates for healthcare workers (HCWs) challenge Belgian HCWs ability to discuss Covid-19 vaccine sentiments with peers and patients. Although studies have identified drivers of HCWs vaccine hesitancy, they do not include effects of workplace interactions and have not addressed con...

Background HIV drug resistance (HIVDR) continues to threaten the effectiveness of worldwide antiretroviral therapy (ART). Emergence and transmission of HIVDR are driven by several interconnected factors. Though much has been done to uncover factors influencing HIVDR, overall interconnectedness between these factors remains unclear and African polic...

Healthcare workers are a priority target population in current COVID-19 vaccination strategies because of their increased workplace exposure and contacts with potentially at-risk patients. In some European countries such as Belgium, Greece, and France, COVID-19 vaccination is now required for this group. However, studies show that a varying but oft...

HIV drug resistance (HIVDR) is a complex problem with multiple interconnected and context dependent causes. Although the factors influencing HIVDR are known and well-studied, HIVDR remains a threat to the effectiveness of antiretroviral therapy. To understand the complexity of HIVDR, a comprehensive, systems approach is needed. Therefore, a local s...

Routine vaccination annually prevents millions of deaths worldwide but is underutilized in sub-Saharan Africa (SSA). The complexity of socio-cultural factors impacting vaccine uptake is not well understood. Hence, this paper aims to review the socio-cultural determinants of vaccine uptake and visualize their interrelationships. We conducted a liter...

The distribution of COVID-19 vaccines has proved to be a challenging task for public health authorities in many countries. Among several decisions involved in the task, allocating limited available vaccines to administration points is indeed critical. However, the operation management literature lacks evidence-based mathematical models that could s...

Objective: To investigate vaccine hesitancy leading to underimmunization and a measles outbreak in Rwanda and to develop a conceptual, community-level model of behavioural factors. Methods: Local immunization systems in two Rwandan communities (one recently experienced a measles outbreak) were explored using systems thinking, human-centred desig...

Despite massive progress in vaccine coverage globally, the region of sub-Saharan Africa is lagging behind for Sustainable Development Goal 3 by 2030. Sub-national under-immunisation is part of the problem. In order to reverse the current immunisation system’s (IMS) underperformance, a conceptual model is proposed that captures the complexity of IMS...

Immunization is widely recognized as one of the most successful and cost-effective health interventions, preventing two to three million deaths from vaccine-preventable diseases each year. Although progress has been made in recent years, substantial operational challenges persist in resource-limited settings with frequent stock-outs contributing to...

Background Immunization directly impacts health (SDG3) and brings a contribution to 14 out of the 17 Sustainable Development Goals (SDGs), such as ending poverty, reducing hunger, and reducing inequalities. Therefore, immunization is recognized to play a central role in reaching the SDGs, especially in low- and middle-income countries (LMICs). Desp...

Despite massive progress in vaccine coverage globally, the region of sub-Saharan Africa is lagging behind and not on track for Sustainable Development Goal 3 by 2030. Sub-national under-immunisation, related to geographical and social heterogeneity, is part of the problem. System-wide changes could transform current immunisation systems to become m...

Introduction HIV drug resistance (HIVDR) continues to threaten the effectiveness of worldwide antiretroviral therapy (ART). Emergence and transmission of HIVDR is driven by several interconnected factors. Though much has been done to uncover factors influencing HIVDR, overall interconnectedness between these factors remain unclear and African polic...

Purpose Despite HIV being reported as one of the major global health issues, availability and accessibility of HIV services and supplies remain limited, especially in low- and middle-income countries. The effective and efficient operation of HIV supply chains is critical to tackle this problem. The purpose of this paper is to give an introduction t...

Access to immunization varies greatly across the world. In order to increase vaccine coverage, the required vaccines need to be able to reach the targeted population. However, in low- and middle-income countries, this often turns out to be a challenging task. This article provides a literature review on vaccine distribution chains in low- and middl...

Many rigorous flow models have been developed to support the design of manufacturing supply chains. However, supply chains supportive of Access to Medicines (ATM), like vaccine supply chains, impose considerable additional challenges on this design process. The incorporation of a broader base of stakeholders delivers a balanced set of Key Performan...

Forks/join stations are commonly used to model synchronization constraints in queuing networks. This paper presents an exact analysis of a fork/join station with inputs from stations composed of multiple exponential servers. The queue length process at the input buffers is analyzed exactly using the underlying Markov process. The semi-Markov kernel...

Boarding patients and the extra workload they introduce are a major concern in emergency departments. Currently, research on boarding has focused on the beds that these patients occupy while they wait for admission in the inpatient ward. Little attention has been given to the check-ups these patients will inevitably need while waiting. These check-...

This research investigates the application of Quick Response Manufacturing (QRM) practices by enterprises in Brazil, Europe, and the USA. QRM is a management concept that focuses on time as the key factor in competitive manufacturing, particularly in customer-oriented Engineer and Make to Order (ETO/MTO) production environments. A literature review...

The main goal of this research is to identify whether companies that have implemented the Quick Response Manufacturing (QRM) approach have full knowledge of the QRM principles or have merely applied the elements (principles and tools) that have a close relationship with Lean Manufacturing. Based on a review of the literature regarding the QRM princ...

Manufacturing outsourcing is a key industry trend towards greater operations effectiveness and is related to the discussion of strategic core competencies. We study the issue of contract manufacturing at the strategic-tactical level aiming for robust decisions to accommodate stochastic manufacturing environments and immanent uncertainty of planning...

In general, vaccines are recognized as an important means to protect populations against infectious diseases. We show that vaccines do not behave like commodity goods and elaborate on the key issues for vaccine supply chain design. This paper reviews the literature on model-based supply chain network design in order to identify the applicability of...

In this volume, scientists and practitioners write about new methods and technologies for improving the operation of health care organizations. Statistical analyses play an important role in these methods with the implications of simulation and modeling applied to the future of health care. Papers are based on work presented at the Second Internati...

Many rigorous models have been developed to support the design of humanitarian supply chains. Supply chains supportive of Access to Medicines (ATM), like vaccine supply chains impose considerable additional challenges on this design process. We embed these models in a broader stakeholder based frame-work. This will substantially enhance the societa...

An advanced resource planning model is presented to support optimal lot size decisions for overall performance improvement of real-life supply chain management systems in terms of either total delivery time or total setup costs. Based on a queueing network, a model is developed for a mix of products, which follow a sequence of operations taking pla...

Many rigorous models have been developed to support health care system design. However, embedding these models in a broader stakeholder based framework, will substantially enhance the societal and human impact of the health care service delivery. Moreover, the acceptance of the (re)designed health care system will be much more evident for all stake...

Environmental concern from customers, government and international institution such as EU and others urge the manufacturer to take back their products after use. We address eight different network design configurations from which the manufacturer can select the design for their reverse logistics system based on their requirements. The dominant lite...

In this paper we want to share our findings from our industrial experience in the field of system design, more precisely in production system design. We start by the observation that many rigorous designs of production systems are not facing the implementation success they suggest. We indicate three basic reasons for this: limited stakeholder invol...

The aim of this chapter is to combine two types of problems: a facility location problem, that determines where a facility should be set up in order to serve a set of customers, and a EOQ-based spare parts inventory problem, which seeks to determine the optimal stocking levels of a collection of spare parts. The theoretical findings are practiced o...

An advanced decision support system is presented to answer aggregate planning questions regarding the trade-off between demand (product-mix) and supply (capacity) in a multi period stochastic setting. This tool improves the effectiveness and efficiency of sales and operation planning meetings by accounting for both revenues and costs that are relev...

Modeling of manufacturing systems is a well-established field with growing importance and an increasing body of knowledge. With this maturity, the interdisciplinary motivation rises where the technical aspects of the analysis of manufacturing systems have to be embedded in the economic reality of decision making of an organization. We do not only w...

Research and development portfolio management is traditionally technologically and financially dominated, with little or no attention to the sustainable focus, which represents the triple bottom line: not only financial (and technical) issues but also human and environmental values. This is mainly due to the lack of quantified and reliable data on...

Mass Customization is one of the buzz words of the last decade. However, the purpose of efficiently unfolding multiple variants of a product or service has deep grounded consequences for the business processes and the underlying system. Subsequently, the supply chain structures supporting these processes face many challenges. In this paper we expos...

The multi-attribute assessment of an R&D portfolio is key for a company's long term survival. As sustainability is entering the stage both on the technological and financial as well as the people oriented aspects, a consistent approach is mandatory. Five models help to underpin a balanced evaluation in the light of a B2C company producing kitchen w...

Mathematical models for Aggregate Production Planning (APP) typically omit the dynamics of the underlying production system due to variable workload levels since they assume fixed capacity buffers and predetermined lead times. Pertinent approaches to overcome these drawbacks are either restrictive in their modeling capabilities or prohibitive in th...

Localising facilities and assigning product flows in a reverse logistics environment is a crucial but difficult strategic management decision, certainly when value decay plays an important part. Despite numerous publications regarding closed-loop supply chain design, very few addressed the impact of lead times and the high level of uncertainty in r...

An Advanced Resource Planning model is presented to support optimal lot size decisions for performance improvement of a production system in terms of either delivery time or setup related costs. Based on a queueing network, a model is developed for a mix of multiple products following their own specific sequence of operations on one or more resourc...

This chapter examines the coordination of converging material (component) flows in supply chains under conditions of uncertainty. It is well known that such flows complicate regular material flows. They entail that the components should wait for each other (synchronization time of components) and induce a modified arrival process on the part of the...

The assembly of components is a key element in manufacturing facilities. Nevertheless, literature analyzing the dynamic behavior remains scarce. The paper narrows this gap by studying a generic first-come first-serve assembly system, consisting of two generally distributed component input streams. The field of probability theory serves as a means t...

It is a great honour to contribute to a book dedicated to celebrate the life-time achievements of John Buzacott in the field of modelling stochastic processes in various application areas. John's work has been both fundamental and synthetic, by which other researchers found a well-guided path through the field and were able to develop their own mod...

Research and development portfolio management is traditionally technologically and financially dominated, with little or no attention to the sustainable focus, which represents the triple bottom line: not only financial (and technical) issues but also human and environmental values. This is mainly due to the lack of quantified and reliable data on...

The purpose of this paper is to convince the reader of the usefulness of an integrated financial-operational model and simultaneously help to understand the complex relationships between operational decisions and their influence on the bottom line of the company. The problem is, that many operational models optimize operational performance measures...

Operational models are typically used to optimize operational measures such as lead time, work-in-process or throughput. Unfortunately, these models often do not take into account the financial aspects of the decisions made. Financial models on the other hand try to optimize costs, profits or shareholder's value. Integration with the underlying ope...

We investigate the impact of four variants of supplier managed inventory on total costs and cost distribution in a capital goods supply chain consisting of a parts supplier who delivers parts to an original equipment manufacturer’s assembly plant. The four supplier managed inventory variants differ in the components of inventory costs that the supp...

Lean management is widespread but theoretical models that scientifically substantiate the lean practice are scarce. We show how queuing models of manufacturing systems and supply chains underpin the practice of Lean. Two quantitative performance models which relate the system parameters with the system performance in terms of lead time and throughp...

Different supplier-customer relationship types can lead to different total costs and different distributions of costs over the parties involved. Choosing the best relationship type therefore can should be based of knowlegde of both the total costs, and the resulting costs per party.

A key characteristic of MRP applications includes the coordination of assembly and purchased component requirements by time-phased order releases. In the literature on order review and release strategies, time- phased order releases are described as a worthy alternative to load limited release mechanisms. This paper initializes the development of a...

The formation of manufacturing batches, given arriving orders, is a general problem in practice. In essence, it constitutes a optimization problem. The goal for this problem however, may differ from perspective. Most commonly this problem is viewed from a cost-based perspective, where minimizing costs is the goal. Other views can include minimizing...

The coordination of joint material flows is a key element in supply chain management. Although analytical models for the coordination of materials are of great practical value, literature analyzing them remains scarce. This article contributes to this gap by studying a generic supply chain model. The supply chain is assumed to have a single product...

The planning and decision support capabilities of the manufacturing planning and control system, which provides the core of any enterprise resource planning package, can be enhanced substantively by the inclusion of a decision support module as an add-on at the midterm planning level. This module, called advanced resource planning (ARP), provides a...

This article proposes a supporting framework for the implementation of the material control system POLCA (paired-cell overlapping loops of cards with authorization). The POLCA system is particularly appropriate for environments that involve highly variable demand and large product variety, which force small batch (or even one-of-a-kind) production....

Transportation is an important component of supply chain competitiveness since it plays a major role in the inbound, inter-facility, and outbound logistics. In this context, assigning and scheduling vehicle routes is a crucial management problem. In this paper, a vehicle routing problem with dynamic travel times due to potential traffic congestion...

In this paper, we show that the planning and decision-support capabilities of the MPC (Manufacturing Planning and Control) system, which forms the core of any ERP (Enterprise Resource Planning) package, may be substantively enhanced by including a Decision Support Module (DSM) as an add-on at the midterm planning level. This DSM, called Advanced Re...

In this paper, an overview of different analytic queueing models for traffic on road networks is presented. In the literature, it has been shown that queueing models can be used to adequately model uninterrupted traffic flows. This paper gives a broad review on this literature. Moreover, it is shown that the developed published methodologies (which...

This paper studies the impact of management policies, such as product allocation and campaign sizing, on the required size of the finished goods inventories in a multi-product multi-reactor batch process. Demand, setup and batch processing times for these products are assumed to be stochastic, and the inventory buffer for every product type needs t...

Received: date / Accepted: date Abstract Assigning and scheduling vehicle routes in a dynamic environ- ment is a crucial management problem. Despite numerous publications deal- ing with e-cient scheduling methods for vehicle routing, very few addressed the inherent stochastic and dynamic nature of travel times. In this paper, a vehicle routing prob...

This work is concerned with the efficient design of a reverse logistics network using an extended version of models currently found in the literature. Those traditional, basic models are formulated as mixed integer linear programs (MILP-model) and determine which facilities to open that minimize the investment, processing, transportation, disposal...

In this paper, we show that the planning and decision support capabilities of the MFC (manufacturing planning and control) system, which forms the core of any ERP package, may be greatly enhanced by including an advanced resource planning (ARP) module as an add-on at the midterm planning level. This ARP module enables to estimate the impact of vari...

It is important to understand the factors that influence the success of IT outsourcing, since IT outsourcing touches the core of organizations. The hypothesis in this article is that benefits management and strategic alignment influence the success of IT outsourcing. The research question is 'do strategic alignment and benefits management contribut...

Transportation is an important component of supply chain competitiveness since it plays a major role in the inbound, inter-facility, and outbound logistics. In this context, assigning and scheduling vehicle routes is a crucial management problem. In this paper, a vehicle routing problem with dynamic travel times due to potential traffic congestion...

Fork/join stations are commonly used to model synchronization constraints in queuing network models of computer and manufacturing systems. This paper presents an exact analysis of a fork/join station in a closed queuing network with inputs from multi-server stations with two-phase Coxian service distributions. The underlying queue length process is...

In this paper, the efiectiveness of state-dependent queueing models for analyzing tra-c ∞ows is tested by comparing the speeds gen- erated by the queueing models with the ones obtained by simulation. Sim- ulation is thus used to evaluate speeds generated by the difierent queue- ing models. Difierent state-dependency functions are described and thei...

In this paper, the use of queueing theory for modeling unin-terrupted traffic flows is evaluated. Empirical data on speeds and flows are used to evaluate speeds generated by the different queueing models. Using the Theil inequality coefficient as evaluation criterion, the speeds generated by the queueing models are compared to the empirical speeds....

This paper analyses the effectiveness of policy measures aimed at triggering a modal shift in the freight transport market. The analysis is based on the inventory‐theoretic framework that studies modal choice from a business logistics viewpoint. The crux of the inventory‐theoretic approach lies in the fact that explicit attention is paid to all cos...

Current supply chain policies are increasingly influenced by the lean philosophy, which calls for increased synchronization and smaller but more frequent shipments between the supply chain partners. One of the strategies used in this respect is lot splitting, i.e. the splitting of a single order quantity among multiple deliveries. Lot splitting is...