The province hardest hit by the December 2004 Indian Ocean tsunami, in which about 170,000 people died, is still rebuilding homes and livelihoods devastated by the disaster.
"In many places, the situation is better than it originally was, but in some places it is not yet as good as it used to be," Pieter Smidt, head of the Asian Development Bank (ADB) mission in Sumatra, told IRIN.
Smidt heads ADB's tsunami recovery project in Aceh. He said Indonesia's Aceh and Nias Rehabilitation and Reconstruction Agency, or BRR, would end its mandate in April 2009. About US$6 billion had been invested in Aceh's reconstruction so far, he said.
"This [InaTEWS] is definitely a very good investment from the international community and the government," Smidt said.
The early warning system can reportedly predict and disseminate news of a possible tsunami within five minutes of an earthquake, according to the National Meteorology and Geophysics Agency.
"This will give people around 30 to 40 minutes to evacuate and save their lives," said Edie Prihanto, assistant to the deputy for technological needs analysis at the Ministry for Technology and Research.
Prihanto told IRIN they began developing InaTEWS in 2005, after the government decided that a warning system had to be developed "at any cost". The meteorology agency said about 57 percent of Indonesia's 81,000km of coastline was vulnerable to tsunamis.
The system, which consists of buoys linked to detectors on the seabed, was developed at a cost of 1.4 trillion rupiahs ($130 million). Germany contributed 45 million Euros ($56 million) to the project, while China, Japan, the USA and France contributed equipment and technical assistance.
Since 2005, the government has been conducting tsunami preparedness drills in various parts of the country every year on 26 December - the annual anniversary of the 2004 tsunami.