A system includes a first network with a first computer and a first release computer; a second network with a second computer and a second release computer; a perimeter network with a first data server and a second data server; wherein the first network and the second network connect via a firewall to the perimeter network; the first data server has a storage area accessible to the first computer and a storage area inaccessible to the first computer and the second computer; and the system is configured to carry out the method.