I want to build a report which shows who is current assignee of the task and who was previous owner of the task.

@ambrishs695, Just wanted to check, if the requirement is to have this for any of the new process models, can we try to create two variables and use them to track the taskOwner and PreviousTaskOwner.. initially update both of them to the same user and assign the taskOwner to the new user in the Reassign Task so that we will be able to capture both?

Thank you all.
I am planning to use the plugin mentioned and I verified that it keeps the task id same after reassignment. So I can store old task owner and new task assignee in pv and then in DB to create a grid to show an audit history of task reassignment.

Glad to know that the suggestions helped you to make the decision. Please let us know how the implementation works for you!

Our Requirement was to re-assign task to original task assignee group. And below is the process how I implemented it.
So I created a paging grid and this grid uses ProcessAnalytics function to returns list of tasks using Process as context. On Paging grid user can select tasks they want to re-assign. Once we get list of all such tasks including other attributes we call Task Smart Service plugin(Re-assign Task Smart Service) as MNI node by passing task Id as input and original Assignee as second input and this service does the job of re-assignment. After this we store all the data like task name, task id, new assignee, old owner in database and display audit history in a grid.