The authors are affiliated with the Institute of Medical Biometry and Medical Informatics, University Medical Center Freiburg and the Freiburg Center for Data Analysis and Modelling, University of Freiburg, Germany. Jan Beyersmann is Senior Statistician and serves on the editorial board of Statistics in Medicine. Arthur Allignol is Statistician and one of the maintainers of the task view 'Survival Analysis' at the Comprehensive R Archive Network. Martin Schumacher is director of the Institute of Medical Biometry and Medical Informatics, Freiburg.