A consultant is responsible for performing every single activity to make sure that the project is successful in every sense. That’s the reason the detailed requirement gathering is conducted to make sure that a consultant knows and understands all the business requirements in detail, including the current way of report generation and the way the analysis is done for decision making by management.
Most of the time, the detailed requirement gathering discussion happens with the middle or the lower management, who are currently generating the reports and feeding the management with the analysis. But it is also important for a consultant to have a couple of meetings with the senior management or the respective management who can help to get the answers to the must ask questions.