Project manager’s decisions are analysed by studying the chosen options and project performance in the business game SimulTrain®. A simulation provides an excellent opportunity for data mining and analysis because all participants manage similar projects and face the same challenges. The results of project simulations carried out by more than 8000 project managers and students of business
schools around Europe show the differences between participants’ choices and experts’ opinions. The analysis highlights the major shortcomings of project delivery,
decision making, and risk reaction and lists the common mistakes made by managers. Further, it demonstrates that managers’ proactive behaviour and risk prevention attitudes as well as investing into communication and team development result in better project performance.