My first journal paper now available open access

My first journal paper of my PhD research was published last November. It was my first scientific paper ever. Although I have written many reports and papers over the past 20 years, writing a scientific paper was something else. It was a team effort of all authors. It was peer reviewed twice. It took a time: 1,5 year from first submission to publication.  This week I received an offer from the publisher to make it open access (for free). Good news, now people can now actually read it!

You can read or download it on the website of SAGE: If this link does not work, then search on ‘Identifying logistical parameters in hospitals’ or copy DOI code 10.1177/0951484818813488 into the internet search engine.

This paper is about the logistical parameters that are used in research on hospital logistics. The aim of this research was to see what logistical parameters are mentioned in international literature. I was particularly interested to see which parameters were mentioned in relation to hospital strategy, because in my experience logistics and hospital strategy did not seem to go together (see an earlier blog).

To put it bluntly I hardly found anything on logistical parameters in relation to hospital strategy and on the operational level I found, well, maybe I should say, too many logistical parameters. There were 106 in total.

What are some practical lessons to be drawn from this paper?

Local and global logistical parameters 

One of the reviewers of the paper commented that it would be very useful to be able to draw some kind of framework from this, in order to present decision makers with a useful tool for controlling hospital logistics. That would be extremely useful indeed, I agree, but how on earth would that be possible? Not only did we find 106 logistical parameters, they were mentioned in the context of 92 very different subsystems of the hospital. I think we have to distinguish between local parameters – relevant in a particular context or department – and global parameters that have a hospital wide relevance and impact. It is related to the issue of the right ratio between integration and differentiation in a hospital (see this blog).

Define logistical parameters that are relevant for the context 

Another thing that struck me is that logistical parameters were not defined clearly (or not at all) in several papers. Throughput time and lead time for example seem to be used as interchangeable words, but are they really the same? So a first step towards any framework would be to define what is meant with these logistical parameters. A next step would be what norms are useful: when does waiting time become a bad thing? This can be valued in different ways in different contexts, subsystems or even situations. Frameworks therefore need some kind of standards, but also need to be flexible, that is: using different standards for different situations. Standards will have to be developed in the hospital practice and there needs to be a debate about them between the different agents in the hospital.

Find the relation between logistical parameters

It is important to relate logistical parameters to one another. We all understand that if there is no waiting patient in the holding, the utilization of the surgeon in the Operating Room will be low. So utilization and waiting time are related. That is easy. With 106 parameters this leads to a very complex model. But I believe it is essential for hospital management.

Optimization or balancing 

Most people want to optimize, to achieve the best possible result. In the over 1000 research papers that I read, in the individual studies researchers tried to optimize one or maybe two parameters. However, this optimization of one logistical parameter can lead to undesired effects for other parameters. It’s not just that we have to know how parameters influence each other, perhaps we need to balance parameters. I am not really sure yet how this should work, but it would mean something like getting all parameters at their most feasible optimum, in relation to each other.




Anesthesiology: a hidden logistics power?

When I started my case study research in the hospital, somewhere in the back of my mind there was this thought: I have been working in hospitals for over 10 years, so what more will I learn from this? Of course I did not really believe the answer to be ‘little’ – otherwise I would not have even started the research – but in hindsight I must admit it was a bit confronting when I realized that some things, I discovered in my research I had not known or seen before.

One of those things was the role of both the Anesthesiologist and the Nurse Anesthesist. First of all, about the name. When my paper – currently under review – was proofread, I had a discussion about the word Anesthetist and Anesthesiologist. In Dutch we say ‘Anesthesist’ or ‘Anesthesiologist’ for the medical specialist who is responsible for the administering of anesthesia to patients. In English the ‘Anesthetist’ can be either a doctor or nurse who has been trained to administer anesthetics. In Dutch we call a nurse who assists the ‘anesthesist’ an ‘anesthesie medewerker’ (which translates into something like ‘anesthesiology co-worker’). I decided to call this assistant to the Anesthesiologist the Nurse Anesthetist.

Although it is interesting that apparently the name and role of people involved in Anesthesiology is different in different countries or languages, the real eye opener was that both the Anesthesiologist and Nurse Anesthetist play an important role in the logistics of surgery in a hospital. The Nurse Anesthetist has the highest centrality in the entire network (see previous blog on nurses). He or she  – there are also a lot of men who are Nurse Anesthetist, as opposed to other types of nurses who mostly seem to be women – decides at what moment the patient is called to the holding and later accompanies the patient from holding to recovery. The Nurse Anesthetist overlooks the process from ward to OR and presents himself to the patient as his or her ‘guardian angel’ (OK, this is what I call it, because it sounded very comforting when in the holding they say something like: ‘hi, my name is Peter and from now on I will be with you the whole time’). Further, the Nurse Anesthetist represents the Anesthesiologist in the Operating Room (OR), when the Anesthesiologist is not there. In short, the Nurse Anesthetist overlooks the process of the patient, accross the walls of the Operation Room (Theatre).

With regard to the Anesthesiologist, he or she plays an important role in making sure that the day program of the Operating Theatre (OT) runs smoothly. Even though this is the prime responsibility of the day program coordinator, the program coordinator consults the Anesthesiologist to discuss last minute changes to the program and asks them on occasion to first consult these changes with the surgeons, before he does. The Anesthesiologist has an interest in a smoothly running OT program, because he works in two operating rooms at the same time. Any unexpected delays or lateness in one OR have an impact on the other OR that he is working in. This is inconvenient and not in his best interest. In addition to his own interest, the Anesthesiologist is more qualified to discuss medical matters with surgeons than coordinators, who are not medically trained.

So, Anesthesiologists and Nurse Anesthetists tend to look at the whole OT system on a day, rather than just focusing on administering anesthesia for one patient in the OR. This perhaps makes the Anesthesiologist a hidden logistics power in the hospital system for surgery or patients.


In response to this blog I was happy to receive feedback from Anesthesiologist Marcel de Korte of Maastricht UMC+ in the Netherlands, stating that the system of Anesthesiologists working in two parallel OR’s is a typically Dutch way of working. However, often, in other countries it is the Nurse Anesthetist who switches between OR’s and the Anesthesiologist who stays in one OR. He adds that nevertheless, according to his view, Anesthesiology plays an important role in OR logistics. 

Regarding the hospital as factory

One of the fun things about doing observations in a hospital is that you see lots of unexpected things. When observing surgeries or patient consultations in the outpatient department I was introduced to doctors and nurses. After been told what my background was (systems engineer/consultant) some asked whether I was going to investigate how efficient they really worked (‘uh no, not really’). At the same time many classified their hospital as a ‘production hospital’. Based on this I got the impression that this indeed was a factory in which patients are treated in a smooth and standardized process. In the observations I was surprised that nurses and doctors were very much focussed on being on time and organizing tasks as efficient as possible, even when the circumstances obstructed this. This could be because I was there (you never know) but I don’t really think so, given the many times I was in the hospital. The more surprised I was when I analyzed the ‘production data’.

This figure shows the yearly volume of all surgery codes and how much variation there is in surgery time (standard deviation as a percentage of the average surgery time). First of all there are many surgeries that are performed less than 100 times a year (less than twice a week). There is one type of surgery that is performed over 700 times a year. Secondly most surgeries have a variation in surgery time between 20% and 60%.

Volume variability

Further I discovered that there are 187 unique routings for 10,000 surgery patients, from outpatient deparment to discharge from the ward after the surgery took place. There are 2881 unique combinations of medical instruments being used for surgeries and 7640 unique combinations of people participating in one surgery. 

This apparent variability is interesting because it does not seem to reflect the factory metaphor at all. In a factory such variability would be challenging (if not impossible) for mass production or even mass customization. According to Johnston et. al. [1] high variation and low volume processes require a high decision making autonomy and flexible interaction between people. This may be reflected in the social networks I made.  Lean and Six Sigma focus on standardization and variability reduction, an approach that fits a process with low variability and high volume, according to Johnston et. al. [1]. Following this reasoning perhaps lean/six sigma are not the panacea we are all hoping for.

However, this conclusion is premature. First of all we don’t know what causes this variation: is it caused by patient demand and/or caused by the hospital itself? Is the autonomy of doctors the cause or the effect of variation? Is variation avoidable or would we be able to reduce it? Another issue are the data; do the 394 surgery codes really represent completely different types of surgeries? Without central master data management for surgery codes, there could be multiple codes for the same type of surgery. If that is the case, then production volumes shown here are too low.  In conclusion, further research is recommended…..

[1] See this paper of Henri Boersma, Tiffany Leung, Rob Vanwersch, Elske Heeren and Frits van Merode

Surgeons: the hospital’s nomads

Surgeons lead nomadic lives in hospitals. Nomads have no fixed habitation and regularly move to and from the same areas (special thanks to Wikipedia for this non scientific definition, but for this purpose it will do). Surgeons travel between places that are run by nurses, in order to service their patients. Interestingly this type of nomadic life – travelling to where clients are – is seen among gypsies or Roma people, but these are not the first kind of people you think about when doctors are concerned. However, unlike nurses who mostly work from a fixed home base, surgeons move around the hospital. The only thing that comes close to home is perhaps the outpatient department.

In the social network of surgeons this nomadic way of life is not visible, as these networks do not take place and time into account. But you can see something else here. In contrast to nomads, we see in these networks that surgeons do not act as a group. Below you see the social network of one eye surgeon (left) and one general surgeon (right). The eye surgeon clearly has a different social network from the general surgeon. Surgeons do not travel in groups, but alone.

Netwerk oogartsNetwerk chirurg

Another contrast to nomads* is that wherever the surgeon lands he is the ‘primus inter pares’ or ‘the boss’ if you like, when it comes to treatment policy, whether to discharge a patient or how to care for the patient. This can cause an interesting tension between the people who run things at home (nurses) and those who walk by giving the orders (surgeons). From what I have seen in the hospital this appears to be an accepted and natural division of roles (this also includes making jokes or mocking about each other).

What intrigued me when observing these surgeons and analyzing their working schemes was the complete lack of a repetitive rhythm in it. Below you can see three graphs of three weeks. On the X-axis are the days and times of one week. The Y- axis represents doing surgery (1) or doing something else (0). The different colours represent the 5 different surgeons. Each week is different for each surgeon, both in number of surgeries as well as at what time and frequency they do surgery.

Rhythm surgeons

So, not only do surgeons travel all the time, they do so in a variable rhythm. Once on their destination they have to focus on complex tasks, having full responsibility for most of what happens in places they stay in temporarily.

As a consultant I have been involved in many building projects where the personal room of doctors was to be replaced by something like a shared backoffice. Even though it is true that outpatient rooms generally have low occupancy rates, I must admit I now much better understand the doctor’s resistance against losing that space. Without that – or some kind of informal group space – he or she could feel like a real nomad, belonging nowhere.

* I don’t know much about nomads but it is my impression that they do not particularly rule the place they stay in, in contrast to surgeons who (have to) take the primary responsibility and medical knowledge to treat patients.


Science blogging: just do it

This is going to be my first Dutch blog (indeed, bad start!). I was at a conference on science blogging and as most sites I will refer to are in Dutch, this seems like the most obvious thing to do.

Via Rosanne Hertzberger had ik van dit symposium vernomen . Met haar en iets van inmiddels 30 andere mensen zijn we een tijdje bezig om een soort platform op te richten, geheten Open Kitchen Science. Zie ook mijn eerdere blog hierover. Dit symposium sluit daar erg goed bij aan.

Er zijn al diverse mensen die samengevat hebben wat er besproken werd, dus dat ga ik niet herhalen (zie deze blogs van Marten van der Meulen en Jona Lendering, twee van de organisatoren). Hier een paar highlights (ja sorry, ook dat is geen Nederlands) die er voor mij uitsprongen.

Roy Meijer, communicatie adviseur van de TU Delft (‘mijn’ universiteit waar ik nog steeds de alumniblaadjes van krijg maar die ik bijna nooit lees omdat ik het te ingewikkeld/technisch vind…waarbij ik me dan meteen afvraag wat voor rare ingenieur mij dat dan maakt, maarja) benadrukte het nut van bloggen: ‘ze helpen het maatschappelijk debat’, daarbij Carel Stolker (universiteit Leiden) citerend. Daar draag ik dus aan bij, dacht ik, wat leuk. Stories of Science, het verhaal achter het onderzoek van de TU Delft, lijkt me interessant. Dat lees ik dan graag weer wel in het TU blaadje; het verhaal achter de onderzoeker of het onderzoek.

Grappig was dat Jona Lendering duidelijk een bekende blogger was in dit gezelschap maar ik hem niet kende. Als deze man zo leuk schrijft als hij spreekt, dan ben ik straks ook voor de oudheid gewonnen. Belangrijkste punt voor mij was dat hij stelde dat het publiek niet geïnteresseerd is in vakdisciplines of zeer gespecialiseerd onderzoek, maar meer in een onderwerp.

Suze Zijlstra vertelde over overdemuur, waarin geschiedenis in de context van de actualiteit wordt geduid. Super interessant. Geschiedenis was mijn favoriete vak op de middelbare school, precies om die reden. Ik ga deze blog zeker volgen. Haar hoofd boodschap was dat activisme en wetenschap goed samen gaan. Dat is wel een spannende vind ik, want als ik blogs schrijf vraag ik me soms af of persoonlijke gedachten en objectieve bevindingen niet te veel door elkaar lopen.

Sander Ruys van uitgever Maver gaf tips hoe wetenschap in een boek te gieten is. De blog ziet hij als een speeltuin, waaruit ooit een serieus (en lekker lezend) boek uit kan voorkomen, zonder dat het een ‘te lang artikel’ of een dik vormig visitekaartje wordt. Leuk, ga ik misschien wel doen als ik toe ben aan het presenteren van mijn ‘big idea’. Eerst maar eens promoveren (en boven de stof komen te staan, want anders wordt het ook niks volgens Sander).

Podcasten is ook nog een optie, persoonlijk heb ik er nog nooit naar eentje geluisterd, wat niet wil zeggen dat het niks is, maar ik geloof dat ik daar niet aan toe ben (if ever). Leuke andere invalshoek, dat wel. Ook dit verhaal ging heel erg over hoe wetenschap aan een breder publiek aan de man te brengen. Ik vind dat persoonlijk heel relevant en goed. Open Kitchen Science beoogt echter (ook?) wat anders, namelijk om het onderzoek zelf, de data, de methoden en mislukkingen te delen met ‘peers’. Zie verder (een website in wording).

Toen stond de ietwat transgender ogende minister van Engelshoven achter het spreekgestoelte. Iedereen herkende hem als journalist Maarten Keulemans, behalve ik, want ik lees NRC. Een mooi opzwepend betoog aan bloggers volgde – speel, doe gek! – en hij stelde het CBV fonds in. Centen Voor Bloggers. Daar ging de discussie die erop volgde ook over: moet er niet geld komen voor bloggers? En zouden wetenschappers er niet tijd van de baas voor moeten krijgen?

Wat mij daarbij opvalt is dat mensen die wel willen bloggen of iets dergelijks, het soms niet doen omdat het niet als onderdeel van hun taak gezien wordt of hun carrière niet vooruit helpt. Dat verbaast mij nogal. Ik zie onderzoekers toch wel als zeer slimme, autonome, eigenzinnige mensen (en ook dat bleek die middag te kloppen). Als je een promotie onderzoek hebt weten af te ronden (mij moet dat nog zien te lukken hoor), dan laat je je toch niet (meer) door zoiets als een taakomschrijving leiden? Gewoon doen, het werd herhaaldelijk geroepen op deze middag. Zeer motiverende middag was het, om precies dat te doen.





Keeping up with the nurses

I received quite some response on the blog on nurses who run the hospital. It appears that to several people who are a nurse or represent nurses it felt like some kind of recognition or appreciation for what they do. Nevertheless, the fact that nurses ‘run’ the hospital is not necessarily good news. It means that nurses have a lot of activities that are not ‘nurse related’, such as stock management, administration, walking around to pick up materials from elsewhere, transporting patients, calling doctors or other nurses multiple times a day, transferring patients to others. Given the fact that there is a large shortage of nurses, as has been in the news in the Netherlands for quite some time, it seems quite obvious to do something about this.

For my research I observed two nursing wards and I joined nurse Alice in doing her work. Besides the logistical activities I saw her doing, I was struck by another thing. Process researchers or consultants tend to model healthcare processes as a linear series of activities. Below you see what process a surgery patient goes through on the nursing ward: 10 consecutive steps in time (from left to right). This takes place within one day or during multiple days, depending on the type of surgery.

patient proces

This process is not like this at all for nurse Alice. She is doing every step of the way in an order as presented below, or in another order as this is just an example. First the intake for patient 1 takes place, then the intake for patient 2, 3 and 4 and then she receives a call from the nurse anesthetist saying that patient 2 should have premedication now, then the call for patient 1 comes in, then for patient 2 and 3. And so on. The 10 steps are executed for, in this case, 4 patients, in a sort of random order. The order is not fixed as all steps are triggered by other agents than the nurse: the patient (arrives at some point), the nurse anesthetist (calls at some point), the recovery nurse (calls at some point).

nurse process2

Nurses therefore constantly shift between tasks. In factory terms: they have changeovers. I assume this costs valuable time as well. Even if we were to consider a nurse as a machine (which of course is a bit insulting and untrue, because I don’t think machines are as empathic as nurses to name only one thing), we could state that even machines need changeover time. So why not nurses?

What nurses do to manage their work, is to look for information or any sign to make the sequence of events predictable and keep changover times short. They look at the surgery program every 5 or 10 minutes, they call people all day, they ask their colleague who has just been at the Recovery about how other patients are proceeding in the process. Alice who is a experienced nurse had all sorts of signs she would constantly be looking for to make work more manageable. What a job. A bit confronting as well I must say. As I was walking along with nurse Alice and other nurses, I could not keep up with any of them, whether they had long or short legs. Apparently this is part of their training, as someone confided to me: walk fast all the time, but don’t make it look like running.

Centralization without hierarchy: a ground for organizational firework?


Happy new year! These fireworks are in fact nine social networks for nine tasks that are performed in order to do surgeries for patients. The entire network in my previous blog is built up from 23 social networks, one for each task. Tasks are for example: making the master schedule for the operating theatre (OT), admitting the patient to the ward or performing the surgery. The networks shown here all show centralization. Centralization is the extent to which a set of people are organized around a central person. This is seen in the networks here as one or a few persons in the middle, surrounded by people who interact with the central person(s).

You might expect that these central persons have a hierarchical position towards the others; that they are the boss who ask or instruct people to do things. This is not the case. In most cases in these networks the persons in the middle have no hierarchical position towards others whatsoever. The central people in the networks shown here are the OT day coordinator and the OT capacity planner, logistical staff, secretaries and nurses. In fact the people who do have formal power, in the organizational structure of the hospital, do not have central positions in the operational system of the hospital I studied.

So, not only is the hospital run by people in the operational system itself – mainly by nurses -, it appears that the operational system functions largely on its own, independent or loosely connected to management. This reminds me of one of my first blogs in which I was amazed at the unexpected and undesirable outcomes of strategic transformations of hospitals. I am wondering if it is true that management knows so little about how the operational system works that strategic decisions can lead to unpredictable outcomes. They are not able to observe the operational system and data on the operational system do not always seem to represent reality (see previous blog). This has little to do with competence, but rather with the impossibility to oversee the operational system. And perhaps this applies to all of us, people not working in this operational system. And does it also work the other way around? Do people working in the operational system know what other interests (financial, legal, ethical, technological etc etc.) are at stake besides treating the patient? I think connecting the strategic and operational reality is one of the most important challenges of our time. In 2019 I will make a further attempt to make some kind of contribution to that.