Erwin W Hans

Erwin W Hans
University of Twente | UT · Department of Industrial Engineering and Business Information Systems (IEBIS)

Prof.dr.ir.

About

119
Publications
79,589
Reads
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3,155
Citations
Introduction
Co-chair of CHOIR - Center for Healthcare Optimization & Research Director of Education, Industrial Engineering & Management BSc and MSc program Education Officer, Board Member, Beta Research School
Additional affiliations
January 2004 - present
University of Twente
Position
  • Operations Management and Process Optimization in Healthcare
October 2001 - December 2003
University of Twente
Position
  • Multi-project planning under uncertainty
January 1997 - October 2001
University of Twente
Position
  • Resource loading by branch-and-price techniques
Education
January 1997 - October 2001
University of Twente
Field of study
  • Resource Loading by Branch-and-Price Techniques
September 1992 - October 1996
University of Twente
Field of study
  • Applied Mathematics

Publications

Publications (119)
Article
Waiting time in healthcare is a significant problem that occurs across the world and often has catastrophic effects. There are various terms used for waiting time (“sojourn”, “throughput” etc.) and there is no consensus on how these terms are defined. Ambiguous definitions of waiting time make it difficult to compare and measure the problems relate...
Article
Full-text available
Background Every week, radiotherapy centers face the complex task of scheduling hundreds of treatment sessions amongst the available linear accelerators. With the increase in cancer patient numbers, manually creating a feasible and efficient schedule has shown to be a difficult, time-consuming task. Although operations research models have been inc...
Book
This book presents healthcare logistics solutions that have been successfully implemented at a variety of healthcare facilities. In each case, a major challenge is presented, along with the solution approach and implementation steps, followed by the impact on hospital operations. Problems encountered when implementing the results in practice are al...
Article
Full-text available
External-beam radiotherapy treatments are delivered by a linear accelerator (linac) in a series of high-energy radiation sessions over multiple days. With the increase in the incidence of cancer and the use of radiotherapy (RT), the problem of automatically scheduling RT sessions while satisfying patient preferences regarding the time of their appo...
Article
Full-text available
Abstract Background In radiotherapy, minimizing the time between referral and start of treatment (waiting time) is important to possibly mitigate tumor growth and avoid psychological distress in cancer patients. Radiotherapy pre-treatment workflow is driven by the scheduling of the first irradiation session, which is usually set right after consult...
Article
Full-text available
An admission lounge is an emerging type of hospital facility that potentially improves the efficiency and efficacy of the perioperative process. We propose a five-step approach for the design, suitability assessment, and optimisation of an admission lounge. The approach uses a case mix optimisation method to select patients for the admission lounge...
Conference Paper
In external-beam radiotherapy (RT), high-energy radiation beams are delivered by a linear accelerator in a series of irradiation sessions undertaken over multiple days. In this work, we consider the problem of scheduling and sequencing RT sessions considering time window preferences given by patients for the starting time of their appointments. Mos...
Article
Full-text available
Background: In radiotherapy, minimizing the time between referral and start of treatment (waiting time) is important to possibly mitigate tumor growth and avoid psychological distress in cancer patients. Radiotherapy pre-treatment workflow is driven by the scheduling of the first irradiation session, which is usually set right after consultation (...
Article
Surgery groups are clustered surgery procedure types that share comparable characteristics (e.g. expected duration). Scheduling OR blocks leaves many options for operational surgery scheduling and this increases the variation in usage of both the OR and downstream beds. Therefore, we schedule surgery groups to reduce the options for operational sch...
Article
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The study of differences between timetabling research presented in conferences like PATAT or published in Annals of OR and commercial timetabling software used in Higher Education Institutions (HEIs) is essential for the discussion about innovation in both higher education and in commerce. In the field of planning and scheduling, a lot of developme...
Conference Paper
Full-text available
This paper studies the suitability of classrooms for higher education. We propose a model to quantify the suitability, which allows measuring and optimizing the fit of classrooms for a given curriculum event. This model is unique, as there is no such model yet in literature that provides insight into the variables and interrelationships that are re...
Article
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Scheduling appointments in a multi-disciplinary clinic is complex, since coordination between disciplines is required. The design of a blueprint schedule for a multi-disciplinary clinic with open access requirements requires an integrated optimization approach, in which all appointment schedules are jointly optimized. As this currently is an open q...
Chapter
Full-text available
Education logistics concerns the integral planning and control (P&C) of education related activities in education organizations, encompassing activities such as scheduling, facility management, staffing, performance management, curriculum development, and ICT management. It has a significant impact on the overall effectiveness and efficiency of the...
Article
Full-text available
We address a stochastic operating room scheduling problem which consists of assigning an intervention date and operating room to surgeries on the waiting list, minimizing the under- and overtime costs of the operating rooms, and the cost of exceeding the capacity constraints of the system. Uncertainties in surgeries duration, in the arrivals of eme...
Article
Full-text available
Histopathology laboratories aim to deliver high quality diagnoses based on patient tissue samples. Timely and high quality care are essential for delivering high quality diagnoses, for example in cancer diagnostics. However, challenges exist regarding employee workload and tardiness of results, which both impact the diagnostic quality. In this pape...
Article
Full-text available
Inspired by the real life problem of a radiology department in a Dutch hospital, we study the problem of scheduling appointments, taking into account unscheduled arrivals and reprioritization. The radiology department offers CT diagnostics to both scheduled and unscheduled patients. Of these unscheduled patients, some must be seen immediately, whil...
Article
Full-text available
As the number of people diagnosed with cancer increases, demand for radiotherapy (RT) services has been continuously growing. In RT, delays in the start of treatment have shown to increase the risk of tumor progression in various cancer types, and patients experience greater psychological distress when subject to longer waiting times. The RT proces...
Article
Full-text available
Like many hospital departments, the gynecology department of the Jeroen Bosch Hospital experienced difficulties with scheduling outpatient appointments at the medically preferred times. Despite the time invested in creating the schedule, the compliance of the achieved schedules with the preferences of gynecologists is low, and the number of schedul...
Article
Full-text available
Numerous benchmark sets exist for combinatorial optimization problems. However, in healthcare scheduling, only a few benchmark sets are known, mainly focused on nurse rostering. One of the most studied topics in the healthcare scheduling literature is surgery scheduling, for which there is no widely used benchmark set. An effective benchmark set sh...
Conference Paper
Full-text available
Uncovering the selection criteria of HEIs when choosing timetabling applications, using ERP as a reference
Article
Background The delivery of radiotherapy (RT) involves the use of rather expensive resources and multi-disciplinary staff. As the number of cancer patients receiving RT increases, timely delivery becomes increasingly difficult due to the complexities related to, among others, variable patient inflow, complex patient routing, and the joint planning o...
Article
Full-text available
Background The delivery of radiotherapy (RT) involves the use of rather expensive resources and multi-disciplinary staff. As the number of cancer patients receiving RT increases, timely delivery becomes increasingly difficult due to the complexities related to, among others, variable patient inflow, complex patient routing, and the joint planning o...
Article
Full-text available
Door integraal te plannen, verminderen pieken in werkdruk op verpleegafdelingen en gaat de kwaliteit van zorg omhoog. Op de afdeling Orthopedie van het St. Antonius Ziekenhuis Utrecht/Nieuwegein is dit gelukt dankzij een speciaal ontwikkelde systematiek.
Chapter
Full-text available
Biografie Rudy Oude Vrielink is momenteel bezig met een promotieonderzoek aan de Universiteit Twente waarin onderzoek wordt gedaan naar het ontwerp van een sensor data infrastructuur en het gebruik van dynamische planningsalgoritmes, als onderdeel van het vakgebied onderwijslogistiek. Veel aandacht wordt besteed aan privacy en integriteit, aangezie...
Article
Background Pathology departments face a growing volume of more and more complex testing in an era where healthcare costs tend to explode and short turnaround times (TATs) are expected. In contrast, the histopathology workforce tends to shrink, so histopathology employees experience high workload during their shifts. This points to the need for effi...
Article
Full-text available
At the tactical planning level in a multi-project environment, uncertainties are inherent to the workloads, and costs may be involved for using non-regular capacity and violating project due dates. We propose an approach to identify whether non-regular capacities might be needed to meet the projects' due dates. This problem is known as rough-cut ca...
Chapter
In the Netherlands, patients with an acute care demand after office hours often wrongly choose to visit the emergency department (ED), while they could have visited the general practitioners’ post (GPP). This may lead to overcrowding and increased costs. In this paper, we focus on an Integrated Emergency Post (IEP) at a Dutch hospital, where the ED...
Article
Full-text available
In the Netherlands, patients with an acute care demand after office hours often wrongly choose to visit the emergency department (ED), while they could have visited the general practitioners’ post (GPP). This may lead to overcrowding and increased costs. In this paper, we focus on an Integrated Emergency Post (IEP) at a Dutch hospital, where the ED...
Article
Full-text available
Tactical planning in hospitals involves elective patient admission planning and the allocation of hospital resource capacities. We propose a method to develop a tactical resource allocation and patient admission plan that takes stochastic elements into consideration, thereby providing robust plans. Our method is developed in an Approximate Dynamic...
Presentation
Full-text available
Inaugural speech on the occasion of accepting the chair Operations Management in Healthcare, by prof.dr.ir. Erwin W. Hans
Book
Full-text available
English translation of the inaugural lecture of prof.dr. Erwin W. Hans at the University of Twente
Conference Paper
Full-text available
The block time (BT) schedule, which allocates Operating Rooms (ORs) to surgical specialties, causes inflexibility for scheduling outside the BT, which negatively affects new surgeons, new specialties, and specialties that have fluctuation in the number of surgeries. For this inflexibility, we introduce the concept of releasing ORs, and present a ge...
Article
We consider a master surgery scheduling (MSS) problem in which block operating room (OR) time is assigned to different surgical specialties. While many MSS approaches in the literature consider only the impact of the MSS on operating theater and operating staff, we enlarge the scope to downstream resources, such as the intensive care unit (ICU) and...
Article
Full-text available
This paper introduces a shift rostering problem that surprisingly has not been studied in literature: the weekend shift rostering problem. It is motivated by our experience that employees' shift preferences predominantly focus on the weekends, since many social activities happen during weekends. The Weekend Rostering Problem (WRP) addresses the ros...
Article
Full-text available
We propose a mathematical programming formulation that incorporates annualized hours and shows to be very flexible with regard to modeling various contract types. The objective of our model is to minimize salary cost, thereby covering workforce demand, and using annualized hours. Our model is able to address various business questions regarding tac...
Article
The design of container shipping networks is an important logistics problem, involving assets and operational costs measured in billions of dollars. To guide the optimal deployment of the ships, a single vessel round trip is considered by minimizing ...
Chapter
This chapter studies the incorporation of uncertainty into multi-project rough-cut capacity planning. We use fuzzy sets to model uncertainties, adhering to the so-called possibilistic approach. We refer to the resulting proactive planning environment as Fuzzy Rough Cut Capacity Planning (FRCCP). Uncertain workloads are modeled as fuzzy numbers, and...
Article
Full-text available
After surgery most of the surgical patients have to be admitted in a ward in the hospital. Due to financial reasons and a decreasing number of available nurses in the Netherlands over the years, it is important to reduce the bed usage as much as possible. One possible way to achieve this is to create an operating room (OR) schedule that spreads the...
Article
Full-text available
Het sociale leven ? sportactiviteiten, verjaardagsbezoeken, het ontmoeten van vrienden ? vindt vooral in de weekeinden plaats. Dit maakt werken in het weekend voor veel mensen onaantrekkelijk. In sectoren waar de dienstverlening 7 dagen in de week en 24 uur per dag beschikbaar moet zijn, zoals in de gezondheidszorg en de beveiligingssector, dienen...
Article
Full-text available
Tactical planning of resources in hospitals concerns elective patient admission planning and the intermediate term allocation of resource capacities. Its main objectives are to achieve equitable access for patients, to meet production targets/to serve the strategically agreed number of patients, and to use resources efficiently. This paper proposes...
Article
Full-text available
SAMENVATTING In April 2010 is de Centrale Huisartsenpost Almelo (HAP) geïntegreerd met de spoedeisende hulpafdeling (SEH) van Ziekenhuisgroep Twente (ZGT) Almelo in één spoedpost. De Universiteit Twente (UT) heeft samen met de spoedpost onderzocht hoe deze optimaal ingericht kan worden zodat een patiënt zonder onnodige vertraging met een optimale...
Conference Paper
Full-text available
Planning and scheduling of health care processes has improved considerably using operations research techniques. Besides analytical and optimization tools, a substantial amount of sophisticated discrete event simulation tools supporting (re-)design of existing logistical processes in and around hospitals has been developed. Surprisingly, these stud...
Article
Full-text available
This series of discussions presents commentaries on where the field of healthcare operations management is now and possible future research directions, expanding upon the key points raised by Green [Green LV (2012) The vital role of operations analysis in improving healthcare delivery. Manufacturing Service Oper. Management 14(4):488–494].
Article
Full-text available
After surgery most of the surgical patients have to be admitted in a ward in the hospital. Due to financial reasons and an decreasing number of available nurses in the Netherlands over the years, it is important to reduce the bed usage as much as possible. One possible way to achieve this is to create an operating room (OR) schedule that spreads th...
Article
Hospitals aim to deliver the highest quality of care. One key priority is to schedule emergency surgeries as quickly as possible, because postponing them generally increases a patient?s risk of complications. In this paper, we consider the case that emergency surgeries are scheduled in one of the elective Operating Rooms (ORs). In this situation, e...
Article
Daily traffic congestions form major problems for businesses such as logistical service providers and distribution firms. They cause late arrivals at customers and additional hiring costs for the truck drivers. The additional costs of traffic congestions can be reduced by taking into account and avoid well-predictable traffic congestions within off...
Article
To examine the use of computer simulation to reduce the time between the CT request and the consult in which the CT report is discussed (diagnostic track) while restricting idle time and overtime. After a pre implementation analysis in our case study hospital, by computer simulation three scenarios were evaluated on access time, overtime and idle t...
Article
Full-text available
Outpatient clinics traditionally organize processes such that the doctor remains in a consultation room while patients visit for consultation, we call this the Patient-to-Doctor policy (PtD-policy). A different approach is the Doctor-to-Patient policy (DtP-policy), whereby the doctor travels between multiple consultation rooms, in which patients pr...
Article
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Health care planners in countries with a system based on a National Health Service (NHS) have to make decisions on where to locate and how to organize hospital services, so as to improve the geographic equity of access in the delivery of care while accounting ...
Chapter
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Rising expenditures spur healthcare organizations to organize their processes more efficiently and effectively. Unfortunately, healthcare planning and control lags behind manufacturing planning and control. We analyze existing planning and control concepts or frameworks for healthcare operations management and find that they do not address various...
Chapter
Full-text available
In this chapter we present a number of approaches to operating theatre planning and scheduling. We organize these approaches hierarchically which serves to illustrate the breadth of problems confronted by researchers. At each hierarchicalplanning level we describe common problems, solution approaches and results from studies at partner hospitals.
Article
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Zorgvuldige afstemming tussen het schema van de operatiekamers en de verpleegafdeling balanceert de belasting van de verpleegafdeling en vermindert het aantal afgezegde operaties. In samenwerking tussen het Center for Healthcare Operations Improvement & Research (CHOIR, kenniscentrum voor optimalisatie van zorgprocessen en onderzoek in Nederland va...