It is intended to serve as backup in case of a failure of the standard glass cockpit instrumentation, allowing pilots to continue to receive key flight-related information.
It is commonplace for an ISIS to work in conjunction with provisions for auxiliary power (typically a battery unit), as well as harnessing embedded sensors for its readings wherever possible.
For example, the Rockwell Collins Pro Line 21 flight deck, which is fitted to aircraft such as the Cessna Citation XLS+ business jet, features a standby navigation display and engine gauges.
[7][8] Thales also produced an Integrated Electronic Standby Instrument (IESI) dedicated for use on helicopters; in excess of 6,000 such units have reportedly been sold as of July 2020.
[3][10] Additional companies specialising in avionics, such as GE Aviation, Smiths Group, and Meggitt, have also marketed ranges of standby instrumentation using both standalone and ISIS-compliance principles.