How to test requirements

If the biggest mistakes are made when defining what to build (see ), what are the questions to ask when looking at requirements?

Here is a list of 14 sets of questions to get you started:

• Does this work the way our users expect it to?
  Is this consistent with the technical domain of the application?
  Will they be surprised by the way this works?

• Can this be simplified? Is every aspect of the requirement necessary?

• Can this be modified to make it much simpler to implement?

• How will we know when we are done?
  What about all the edge cases? How can we check this?

• Is this consistent with similar functionality elsewhere in the application or interface?

• Is this consistent with similar functionality in other well known applications or interfaces?
  Will this be familiar to the user?

• What are the limits on this functionality?
  How big? How many? How often? For how long?
  What will the application do if those limits are reached?

• What mistakes can the user make?
  How will the application react?

• Is this the best place in the application for this functionality?
  Are there other places this functionality should be available?

• Is this making assumptions? How can the system be sure that they are true?

• Are there accessibility concerns that haven’t been addressed?

• Are there security concerns that haven’t been addressed?

• How will this work for all the different modes that the application can be in?

• How will this work for all the different types of users?

Not all questions will make sense every time and there will be other questions that aren’t on this list, but keep asking questions.