The system was developed at a cost of 1.4 trillion Indonesian rupiahs (US 130 million dollars), with technical and financial contributions from China, France, Germany, Japan and the United States.
According to a report in ENN (Environmental News Network), the new system can warn of an impending tsunami within five minutes of an earthquake and uses new technologies that differ from previous systems.
Existing systems, such as the Pacific Tsunami Warning System, have not suited Indonesia's unique geological situation, according to the Jakarta Tsunami Information Centre.
Indian Ocean earthquakes off the country's coast occur along the Sunda Arc - a subduction zone where one tectonic plate slips under another, which extends from Sumatra in the west to Flores in the east.
Should a tsunami occur in this zone, the waves could, in an extreme case, reach the coast within 20 minutes, leaving little warning time.
To tackle this, scientists have found new ways to improve the speed and reliability of the detection of strong earthquakes, and to effectively model tsunamis.
In particular, InaTEWS makes direct use of a wide variety of different sensors, such as seismographs and buoys to monitor ocean waves.
InaTEWS is supported by new technology known as the Decision Support System (DSS), which collects information from earthquake monitoring systems, tsunami analysis and monitoring systems, and systems that measure the deformation of the earth's crust after an earthquake has taken place.
In 2010, two agencies - the Japanese Meteorological Agency and the Pacific Tsunami Warning Center - will step aside in favour of InaTEWS as the regional warning system for the Indian Ocean, according to Jan Sopaheluwakan, chairman of the Indonesian National Commission for UNESCO's Intergovernmental Oceanographic Commission (IOC).
But, achieving this internationally recognised position requires further work. Its technical capability, sustainability, information systems and training for recipient countries will need improving before it can fulfil this role, Sopaheluwakan added.
According to Sopaheluwakan, Indonesia is the natural host for such a system because of its position on the 'Ring of Fire' - a region of high earthquake activity encircling the Pacific Ocean - and thus close to the sources of tsunamis.