Provided that you have not saved actions that you carried out on the planning board, you can undo each action one-by-one and redo them again.

Choose (Undo:) or (Redo). The quick info text also shows which action you are undoing or redoing (for example, Undo: Create Assignment).

If you have saved the data in the planning board, you can use this function only for actions that you subsequently carry out.