Sven Bertelsen Celebrates his 80th Birthday
19th October 2017

Sven Bertelsen is a true IGLC greybeard. He started investigating the Toyota production methods in construction in 1989, and found and joined IGLC ten years later. He organized the successful IGLC 12 conference in Denmark in 2004. He has contributed to IGLC activities in many other roles: as a technical co-chair, as an author to many papers and as a reviewer.

He has contributed to the lean construction body of knowledge, especially through his studies of construction as a complex and adaptive system. He has published two books in Danish on lean construction, and this year a book in English on project management: “The Unruly Project: Seven Coherent Essays about the Project and its Management”. He writes a biweekly letter circulated among the members of Lean Construction DK.

The IGLC community congratulates Sven on his 80th birthday, and wishes many happy returns! Below, some of the people in the IGLC community who know Sven best say a few words about him.

Sven – complexity, chaos and flow Rafael Sacks - Secretary General of IGLC

Very few people have made such consistent, fundamental and good-natured contributions to Lean Construction as has Sven Bertelsen.

Consistent – from his first lean construction paper in 1997 (titled "Just-In-Time Logistics in the Supply of Building Materials" and delivered to the "1st International Conference on Construction Industry Development" in Singapore), through his numerous IGLC conference papers (21 at last count, and ongoing…), and with his books (especially Semiramis and The Unruly Project), Sven has consistently contributed to the development of lean thinking applied to construction.

Fundamental – Sven's ideas on production in construction have had strong influence in the research community because they have brought a new view: complexity, chaos and flow are keywords that characterize his view of production in construction. Understanding production itself, how it works as a result of how people behave, is at the heart of lean construction research and it is here that Sven has made a fundamental contribution.

Good-natured – unlike production in construction, this is well known to all, and needs neither explanation nor elaboration. Thank you Sven, for being a warm and sincere friend as well as a thought leader, and congratulations on your 80th birthday!

Sven – the creative mind Lauri Koskela - Fellow greybeard

I learnt to know Sven in the IGLC conference in Berkeley in 1999. He introduced himself and gave me a recent Danish report on IT in construction. I thanked politely but perhaps somewhat reservedly – I had had my frustrations with enthusiasts for the idea of IT as the driver for performance in construction. However, first impressions were just wrong: This was a widely experienced engineer with the most creative and curious mind, who would come a research collaborator and a good friend for me.

Already before joining IGLC, Sven had been involved in research on construction logistics, where ideas similar to lean were developed. With new inspiration from lean construction, Sven launched the offensive of changing the construction industry in Denmark. The outcomes are clearly visible today: Lean Construction DK, the national association for advancement of lean construction, is probably more active than any other similar organization in Europe.

Indeed, regarding their impact and outcomes, Sven’s lean construction activities during his retirement from NIRAS, the consulting firm, offer a benchmark for us academics. His papers continually attract citations and prove to be of lasting value; in fact, his paper on logistics from 1997 has up to now in this year received clearly more citations than in any previous year.

I have had the privilege of interacting with Sven countless of times in connection to paper writing, attendance in conferences and workshops and also when visiting him and Sonja. Always has Sven, the creative mind, new ideas to discuss or earlier experiences with bearing on new problems to tell. Especially memorable are his stories from Greenland, where he stayed as a young engineer.

Congratulations, Sven!

Sven – the rider of an unruly horse Glenn Ballard - Fellow greybeard

First and foremost, Sven believes that projects are complex and that we tend to seriously underestimate just how complex they are. Complexity cannot be managed as described in the project management textbooks, but rather in the way an unruly horse is ridden. The ride is always full of twists and turns, so the rider has to be alert and adaptive. The rider must expect the horse to be unruly, and not make the mistake of thinking that this time out of the stable, everything will go smoothly all by itself. An excerpt from my Foreword to Sven’s book THE UNRULY PROJECT.

Sven the integrator Alan Mossman - yet another fellow greybeard

I first met Sven at IGLC in Denmark in 2004. Sven was our host as well as co-editor of the proceedings which I have on the desk before me.

Sven the integrator because I came to know him as someone who is intensely concerned with both the social and the technical. Last week a colleague in the US talked about these two aspects in terms of Hal and Todd respectively. Sven embraces them both.

On the technical side, his interests in Factory Physics, Construction Physics (which is why I have the proceedings open) and complexity for example and on the human, the social side his insistence on using the wonderfully convivial facilities at Helsingør for the 2004 conference so that we would all be co-located, break bread together, his regular attempts to get others to follow that example, to use more Open Space Technologies in meetings of the lean construction community and his interest in the social process of construction.

When, too infrequently, I ask Google to translate Trimmede Tanker into English, there is always good sense. In the most recent edition, as usual, Sven thinks outside the box talking in practical terms about 'Nordic Lean Green' Housing - double the value for half the price – that sits lightly on our over-stretched planet.

Sven, Happy Birthday and many happy returns. Thank you for your service to our planet and to this community and, even though your birthday is on a Thursday this year, may I wish you and Sonia

God weekend


Sven – a fountain of wit, creativity and fresh ideas Sigmund Aslesen

Dear Sven,

It is with a great deal of optimism, joy and not least astonishment that I congratulate you on your eightieth birthday. Astonishment because I find it hard to believe that a person equipped with so much wit, creativity and fresh ideas is not in his youth anymore. Optimism because you show me how growing older can really be a gift, if you let it! Joy because I’ve had such great times in our Holte-meetings just listening to your thoughts, ideas and lively anecdotes from a life in business and research.

Congratulations, my friend!

Sven - the inspiration Fritz Gehbauer

We celebrate your 80th birthday today. For me you are still one of the youngest minds, full of inspiration, creativity, and lateral thinking. Your newest book The Unruly Project gives another proof of that. As you know we are considering a German version of that book. We need here to turn to your way of seeing and handling projects. Happy Birthday!

Sven - a tireless promoter of lean Stephen Emmitt

I joined the Technical University of Denmark (DTU) in 2003 and in my first week I was invited to a meeting on Lean Construction. Present, among many others, were Glenn Ballard and Sven Bertelsen. That meeting started an interaction with Sven and inevitably led to joint authoring of papers for the IGLC, as I recall mostly written by Sven! We have lost touch with my move back to the UK, but I still look back with fondness on my time in Denmark and the ‘lean construction’ years. I particularly remember a lunchtime meeting at a restaurant overlooking the lake at Holte where a visiting academic made the mistake of criticising lean construction. After a short pause Sven merely stated that the visitor was wrong. Sven then proceeded to explain in great detail why our visitor was wrong. As far as a I know the individual in question never returned to Denmark! This sticks in my mind as an example of Sven’s passion for lean construction and his tireless energy in promoting its benefits to the Danish and international community of practitioners and academics. Congratulations (tillykke) on reaching 80 Sven. Enjoy the day.

Sven - The true reflective practitioner Sten Bonke - emeritus

Congratulations, Sven - and thank you for decades of thought-provoking conduct in the Danish Construction community! And thanks for much more than that: for being always on the leading edge in the Danish Construction community, as inspired practitioner and innovator. For bringing legitimacy and commitment to innovative thinking among foot-dragging stakeholders in boardrooms and departmental offices - and on scaffoldings. For embracing theory, not because of its academic ranking but as a means to comprehend and change practise. And for creating and nourishing our new mindset in process management. Thank you for being the - sometimes lonely, I assume - fiery soul on the successful lean construction journey in our unimpressive homeland - and for making it notable on a larger scene. And thanks for insisting on the necessity to transcend constricting borders, irrespective of their nature. Indeed, Sven - we applaud your energy and enthusiasm - and the inconceivable long list of astonishing contributions you keep on generating. Thanks for being such an inspiration and guiding spirit to us. Let your next decade bring further insight and enjoyment to all of us.