Forget statistics - draw graphs instead

This paper describes research carried out at the Rolls-Royce Company in the UK, to develop a tool set to aid planning and decision making regarding the management of a portfolio of IT systems. The research was carried out over three years with one researcher working alongside company employees in teams developing and evaluating the tools. A number of empirical and non-empirical tools were evaluated for their usefulness within the teams for analysing the problems, and for their usefulness in putting the alternative options to senior management. It was found that the most successful tools were the simpler tools where it is easy to understand the output and how it has been derived. Graphical tools depicting non-empirical or simple empirical information were found to be particularly helpful. Statistical analysis, on the other hand, was not found to be useful as the results are generally mistrusted by senior management.