...means that the standard shall be future-proof, i.e. it must be able to follow the progress in communication technology as well as evolving system requirements. Investments in substation automation systems must be safeguarded against obsolescence due to the fast-evolving information technology. From the experience with PCs in our private or office environment, we know how fast this technology is becoming obsolete, maybe even in the course of one or two years. This is unacceptable since no adequate return on investment is generated within such short time. The lifetime of substations is long, maybe up to 60 years. Experiences as reported in CIGRE tell of about two retrofits of protection and control during this time span. Furthermore, extensions and changes might be made to the switchyard. Therefore, the substation automation system shall have an expected lifetime of and be maintainable for approx. 20 years, which necessitates a communication concept with long-term stability. Thus the standard IEC 61850 facilitates the connection of maintained or new, compliant devices at any instant during system lifetime without the need for re-engineering of the complete system. The standard also allows upgrading the communication system to state-of-the-art without touching any functions and databases of the substation automation and higher-level systems. Interoperability must be guaranteed. --> back to IEC 61850 start page