1. A computer-implemented method to generate cumulative metric data for a test in a test environment, the method comprising: specifying, from within the test environment, a plurality of test elements within an iterations part of the test, the plurality of test elements including: a first test element being a simulation model having a block property, the simulation model executed from within a second environment that is separate from the test environment, and a second test element that is not a simulation model, the second test element being executable; generating, from within the test environment, at least one test condition for the test, the at least one test condition specifying a number of values for the block property of the simulation model; specifying at least one metric setting for the simulation model; defining a test variable within the test environment; mapping, from within the test environment, the at least one metric setting of the simulation model to the test variable; running, by a computer, the test from within the test environment such that the simulation model is executed within the second environment for a plurality of iterations based on the number of block property values specified in the at least one test condition, and the second test element is executed for the plurality of iterations; generating, during each iteration of the simulation model, metric data based on the at least one metric setting for the simulation model, the metric data generated within the second environment; assigning the metric data generated in the second environment to the test variable of the test environment as a result of the mapping of the at least one metric setting of the simulation model to the test variable so that the metric data from the iterations of the simulation model is accumulated; and providing access to the accumulated metric data from within the test environment.