ANSWER

The main reason why it is important to prioritize requirements is because like most of us, organizations have finite resources (money, time, employees, etc.)

Since not all requirements can be implemented right way, the business needs to determine which requirements should be addressed first. Without going into the details on how to perform requirements prioritization, we should point out that the ultimate determining factor is ROI (return on investment).

How much money am I going to make/save if I implement this requirement. Yes - most business are about money but this works even for non-financial driven requirements (such as how many more people am I going to convince to vote for candidate X if I implement requirement # 1 vs. requirement # 2).

In order to determine the ROI the business analyst needs to look at a number of factors (aka attributes of each requirement) including but not limited to:

• how important (biggest savings or gain) is the requirement to the business that is, if the cost to implement each requirements was the same, what would be the order of execution,

• how much would it cost to implement each requirement,

• how much would the business lose if they don't implement a given requirement (for example if the requirement is as a result of a law how much could it cost the company if it were to get into litigation for now complying with the law?),

• how long would it take to implement a given requirement; note that longer duration does not necessarily mean increased cost, however longer duration could mean a lost business opportunity which, in turn, might call for not implementing the requirement in the first place.

• etc.

Additional resources:

First Things First: Prioritizing Requirements

Requirements Prioritization Introduction