Although mixing of OR methods is an area of increasing interest to the OR community, there has been little discussion regarding generic lessons that can be learnt from mixing methods in practice. The aim of this paper is to carry out such an analysis through considering generic lessons that may be associated with mixing methods, regardless of the methods chosen. To identify these lessons, published case studies on how OR methods have been mixed are analysed giving rise to a number of themes revealing the lessons. These themes include; the implications from the use of different facilitators/modellers, how methods have been mixed together, the nature of the modelling interventions, the client value and the rationale given for mixing methods. The paper discusses the lessons learnt in each of these themes and presents opportunities for future work.
