Question

when is democracy considered successful?

Answer 1

in the following ways:-

1. when in a country no illegal things like corruption are taking place

2.when people do not conflict on the basis of caste, creed, gender

3. on the time of elections no unfair trade practises takes place

this are some points hope this will help you

Answer 2

Democracy is the dominant form of government in the contemporary world. Some qualifications of democracy must be fulfilled for its success. 
These are
(i) Not rich and powerful people but the rulers elected by the people must take all major decisions.
(ii) The elections must offer a choice and fair opportunity to the people to change the rulers, if they want to.
(iii) A choice and opportunity should be available to all the people based on political equality.