For which purposes it is used

Decision Matrix Analysis enables you to make a rational decision from a number of similar options. It is best to use the tool when the options look fairly similar to each other yet you want to objectively decide which is the best option. By using the tool you ensure all important factors have been considered before an option is selected, and thus the tool prevents you from potentially jumping to the wrong conclusion and selecting the wrong option.

It is most useful when you have several options and you need to decide between them based on a number of different factors.