Business Analyst as the name indicates is responsible person to gather requirements from the user and document them and also understand the process from users without using any tech words. DFD’s and work flow diagrams come in Business Analyst domain. On the other hand systems analyst will be responsible to interact with Business analyst to lay out the details. Most of the mid sized organizations merge both roles. The Systems Analyst role attempts to provide a bridge between the business requirements and the technical definition of the IT solution.