The International Crisis Group (ICG) said on Thursday that holding a referendum on the constitution, local elections, national assembly elections, senate elections, and presidential elections over the next five months is essential.
"The calendar appears reasonable and realistic," said Suliman Baldo, the Brussels-based group's Africa programme director.
"Still, there are many things to be done. All the funds necessary to conduct an electoral census and to organise the referendum have not yet been released."
Burundi has been plagued by tension between the dominant Tutsi minority and the Hutu majority and has been the scene of one of Africa's most intractable conflicts.
From 1993 to 2002, hundreds of thousands of people were killed in Hutu-Tutsi violence.
However, the peace process is well on its way to becoming a success, said the ICG.
"The calendar appears reasonable and realistic. Still, there are many things to be done"
International Crisis Group
Negotiations on power-sharing and a constitution have been completed, and the remaining rebel force still fighting in the field is too weak to upset the arrangements.
But the ICG warned that the sustained support of the international community is vital to carry the peace process to fruition.
The United Nations Operation in Burundi (ONUB) is mandated to assist Burundi in organising elections and in the process of disarming, demobilising and reintegrating combatants, as well as in the creation of a new national army.
"The process will not be credible, however, without the necessary international support", said Susan Linnee, the ICG's Central Africa Project Director.
"Burundi cannot achieve peace on its own. This tortured country needs immediate, sustained commitment."