SIMLAB 4.0 is a comprehensive stand-alone software package for performing global sensitivity analysis. Several sampling strategies and sensitivity measures are available. SIMLAB includes the most recent variance-based formulas for first-order and total-order sensitivity indices, graphical methods, as well as more classical methods. The peculiarity of SIMLAB, in contrast to previous versions of the package, is the possibility to run sequential sensitivity analysis, which allows updating the sensitivity measures at each run, or group of runs, of the model. The techniques can be accessed through the R environment as well as through a graphical user interface. The user can also add new techniques by
simply adding the corresponding R code to the core layer. SIMLAB can be downloaded for free from the Joint Research Centre’s website.