Prof Vicky Mabin part of Griffiths Medal winning team

Prof Vicky Mabin is one of the authors that have been awarded the Griffiths Medal for their paper Using the Theory of Constraints to resolve long-standing resource and service issues in a large public hospital. See below for more details. Congratulations to Vicky and her fellow authors.

“Congratulations to Prof Vicky Mabin, Julie Yee, Sally Babington, Dr Vanessa Caldwell, and Robyn Moore for being awarded the Griffiths Medal by The Operational Research Society. Based in the UK, the ORS is the oldest and biggest OR society in the world representing a profession at the very heart of analytics.

From left: Prof Vicky Mabin, Julie Yee, Sally Babington, Dr Vanessa Caldwell and Robyn Moore, Griffiths Medal winners for 2019.

The Griffiths Medal 2019 is awarded by The OR Society for the best paper in Health Systems journal in the preceding two years.

If you think that the only way to improve health services is by adding more resources, think again! The paper describes how we used Theory of Constraints (TOC) to address the resourcing issues caused by rising demands and fixed budgets that plague public hospitals everywhere. A pilot implementation changed the decision rules for determining when the pharmacy supplied chemotherapy drugs. This led to an improvement in average patient wait times of 87%, 37% increase in production, two-thirds (67%) reduction in nursing overtime, reduced stress levels, while drug costs were held constant. The resulting two-tier system has been in place and working well for over 12 years.

As the Griffiths Medal winner, the paper is free to access for a year

Using the Theory of Constraints to resolve long-standing resource and service issues in a large public hospital. Health Systems 7(3), 230-249

Keywords: Theory of Constraints (TOC); change; Operations research; health services; problem structuring; resource conflicts; Chemotherapy; Hospital; Health services

In 2006, Julie, Sally and Vanessa undertook an initial thorough analysis using TOC with Vicky’s guidance as part of an MBA Problem Solving and Decision Making course that Vicky taught. Julie led the pilot implementation in the hospital in 2007, Robyn helped compile the paper and with Vicky, undertook further research to see the paper through to publication in Health Systems. Julie now works for ACC, Vanessa for Mid-Central DHB, Sally for DOC, while Robyn is an operations researcher and local business owner.

The path to publication was a long and unusual one. Believe it or not, an earlier conference paper describing this project was copied extensively without any acknowledgement, amounting to an alarming case of plagiarism. While the journal supported our complaint and immediately removed the offending paper, after revision by the authors Syed Amin Tabish and Syed Nabil to delete all traces of our work, incredibly, their paper was reinstated. We were therefore particularly gratified to have our paper published in the reputable Health Systems journal, and especially delighted to receive the Griffiths Medal.”

Some diagrams from Vicky’s paper:

The research changed the situation from this:

to this:

giving the following results:

2018 ORSNZ Conference Highlights + Prize Winners

The Joint NZSA/ORSNZ Conference was held at Massey University in Palmerston North from 27th – 30th November 2018.  This conference incorporated the 69th Annual NZSA Conference and the 52nd annual ORSNZ Conference.

During the 4 day conference there were five excellent plenary talks from: Prof. Geoff Jones,  Prof. Stefan Nickel,  Prof. Alan Welsh, Prof. Jean Yang and  Assoc. Prof. Ilze Ziedins on various aspects of statistics and operations research. There were also over 60 contributed talks from students, academics and practitioners. The book of abstracts is available here

On Thursday 29th November an Analytics Forum on the theme “Analytics in the Primary Sector” was held in conjunction with the conference.  Interesting insights into the industry were provided by speakers Vanessa CaveKim Frew, and Mark Piper. The Analytics Forum event was sponsored by Fonterra.

The ORSNZ conference dinner was held on Wednesday 28th November, and as well as enjoying delicious food and good company, we celebrated the success of our students.  We congratulate the following prize winners.

  • Young Practitioner Prize (YPP)
    • 1st place: Isaac D Cleland, University of Auckland, PhD (Engineering Science)
    • 2nd place:  Jesse Prendergast, University of Auckland, ME (Engineering Science)
    • 3rd place: Haddon Smith, University of Auckland, BE(Hons) (Engineering Science)
  • John A. George (JAG) Memorial Prize
    • 1st place: Haddon Smith,  University of Auckland, BE(Hons) (Engineering Science)
    • 2nd place: Jesse Prendergast, University of Auckland, ME (Engineering Science)

Further information about the prizes and winners are available here:

YPP Prize Winners









JAG Prize Winners

ORSNZ member, Bob Cavana, co-editor of new book on “Systems Education for a Sustainable Planet”

ORSNZ member, Bob Cavana, along with colleague Ockie Bosch, are co-editors of new book on “Systems Education for a Sustainable Planet”,which has been published by MDPI, in print and electronically. The new book, which is a special issue of the international journal “Systems”, presents a collection of papers addressing important systems education and sustainability issues. As stated in the preface: “The range and magnitude of contributions to this book illustrate the diversity of systems education practices and programs (learning systems) in the global systems community, and the relevance of systems thinking and practice to examining issues related to the long-term sustainability of the planet.”

Further details about Systems Education for a Sustainable Planet are available at: