Prof Marshall is a researcher within the School of Mathematics & Physics and the Intelligent Autonomous Manufacturing Systems Centre.  Her research has specialised in Coxian phase-type distributions. Since commencing work in this field in 1997, the area which had barely any research is gradually gaining momentum with more and more researchers wishing to explore the models for alternative use, further research and development and application.  Alongside this, Prof Marshall’s work through CenSSOR has led to Queen's being seen as experts in this field. In the last 2 years, major developments in the coding has resulted in the various models now becoming much more accessible to researchers in other domains. Future research in this field is very promising.  The original research focused on healthcare of the elderly. The UK Health Reform in 2010 and growing needs for all countries to plan and manage elderly healthcare and its associated costs makes the research extremely topical and relevant to have impact on society.