David Parry Auckland University of TechnologyPrivate Bag 92006, Auckland, New ZealandDave.parry@aut.ac.nzJudith SymondsAuckland University of TechnologyPrivate Bag 92006, Auckland, New ZealandJudith.symonds@ aut.ac.nz Jim BriggsCentre for Healthcare Modelling and InformaticsUniversity of Portsmouth UK