In the Business Process the BA's need to be giving their all in for the betterment of work and being most productive for the organisation and getting most of the output form the driven task.

(NOTE:- Here, refer UAT as User Acceptance Test)
1. BAs understand the functionality the system is supposed to deliver and as such, have the knowledge needed to validate the system (confirm whether the solution meets business needs or not). The fact that a system has been built to specification does not make it automatically acceptable. UAT helps stakeholders to determine whether the system can be put to use in real-life business scenarios or not

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2. The UAT session is an opportunity for users to see the solution in action and confirm that it meets their needs. Users need to test their own systems to ensure that it works the way they expect it to, to prevent drastic changes after the system has gone live and to increase the chances of project success.
Getting involved in UAT presents an opportunity for the BA to confirm the correctness of previously elicited requirements and improve on future projects.
3. Even though it's recommended that users see prototypes of the proposed system and are kept informed throughout the software development lifecycle, change requests still come up during UAT sessions.
Being part of the UAT session will help the Business Analyst understand the rationale for any proposed change, suggest the most appropriate way to meet the business need and help in selling the idea to the Change Control Board.
4.Though the objective of UAT is not to train users, they would need to understand how the system works to test it effectively. When BAs who have a firsthand knowledge of system functionalities are involved in UAT, they are able to support training efforts prior to UAT and answer users' questions during test sessions.
5. As part of solution validation, the BA may be brought in to support the team in assessing the severity of defects, their impact on the business, which defects must be resolved before go-live and what can be done to mitigate the risks of the defects that cannot be resolved.
These are some important parts where a BA needs to be giving a full dedication especially in testing phase.
