This chapter covers scenario analysis using the Simul8 simulation software. Systems are compared using the visual inspection of confidence interval graphs and the use of a paired t-test. In chapter 9C, in order to undertake a confidence interval analysis of a single model, we made changes to the double-queue bank clerk model to make it a ‘true’ terminating system. Here, we will compare the performance of the double-queue system to the single-queue bank clerk system, so we need to repeat the changes to the double-queue system for the single-queue system. To do this, load the single-queue bank clerk simulation (see chapter 7C) into Simul8.