This BBC article examines the future of the early warning system.
The final part of the jigsaw is getting the warning message from tsunami monitoring centres to Jakarta and - in a matter of minutes - to often isolated communities.
It is in this area that Koichiro Matsuura, director-general of the UN's scientific and cultural organisation Unesco, acknowledges work remains to be done.
While the new warning system had "functioned well" in terms of information reaching Indian Ocean governments, he said in a statement, the authorities had to ensure that messages "make the final mile to the people on the coast".
"The system still has big gaps, notably in getting the warning to coastal communities in time," he said.
Communications seems to be one barrier that is preventing the warning from reaching isolated communities.
In the meantime, officials were making use of SMS messages to contact communities at risk, he said.
Networks of sirens are also being set up this year in the Aceh, Padang and Bali regions to alert people who may be too poor to own TVs, radios or mobile phones. Another is to be built in Java next year.