In MESBuilder processes do not have to be one on one related to machines. That means that one process may be performed sequentially over a number of machines . For instance : in one occasion process steps 1 to 7 of a process can be carried out on machine 1 and process steps 7 to 15 can be carried out on machine 2. However, if the machines it permit another identical process can be carried out entirely on machine 1 or 2. Processes and materials do not show a mandatory relationship with a machine type but an optional . This is something that occurs frequently.