A bubble diagram, alternately referred to as a portfolio map, is a technique used to evaluate organisational projects on the basis of their characteristics or properties. An X-Y map is created, with certain characteristics represented by each axis, for example ‘risk’ on one axis and ‘reward’ on the other. The project under evaluation is then plotted using a bubble to represent its performance for each of these characteristics. To aid users, additional characteristics or properties can be added by using various ‘bubble’ sizes or colours. The approach facilitates the comparison of projects, provides a balanced view of the portfolio, and identifies criteria essential to decision making.