Business Analysts have been in great demand nowadays and if you are also looking to crack a BA interview, then here are the most asked questions list. Most popular diagrams used in your field? Use Case Diagram and Collaboration Diagram are the most common thing every Business Analyst must know. You can also explain a little about both the diagrams. If you are not a fresher then you also might have few examples to cite where you used both the diagrams in your previous organization.