After you have validated and verified your model, you need to design your experiment, which involves determining the factors, levels, scenarios, and replications that you want to test. Factors are the variables that you want to manipulate or change in your simulation, such as demand, capacity, lead time, or inventory policy. Levels are the values that each factor can take, such as high, medium, or low demand. Scenarios are the combinations of factors and levels that you want to compare, such as high demand and low capacity versus low demand and high capacity. Replications are the number of times that you run each scenario to account for randomness and variability in your simulation.