Virtual commissioning enables early test and verification of machine software by using simulation model of a machine. With the growing complexity of machinery, a system model can be used to validate interaction between mechanics, software, and the product being manufactured can be tested, optimized and verified in different scenarios before the physical machine is available. This lecture will consider the design of a tension controller for a plastic packaging machine as an example to highlight how virtual commissioning lowers costs, ensures high product quality, and speeds up commissioning times.