In order to reduce cost driving elements like various interfaces to field equipment and other systems, it is necessary to limit and standardize these interfaces. The following guidelines shall apply:• As few as possible hardware typical for interface to field instruments and the types.• Standard, well-proven and documented protocols.• Standard documented and tested software modules (function blocks) for interface to field or other systems.The overall philosophy shall be to use well-proven, cost-effective solutions and equipment, - both with respect to hardware and software.