Almost every item in Project Insight has a History tab in its Task Details page. Let me know in the comments below if the item you need does not have a History tab, and we'll take a look at it.
But as I was saying, items have a History tab on the detail screen:
This tab is designed to track the changes that happen to this item, but we caution you not to consider it an audit trail.
There are certain events that trigger a history entry, so you may find certain changes are not listed in the History.
Please let us know in the comments if you want to see a certain event leave a history comment.
Most events like changing a date or a resource assignment will leave an entry in the History tab. You will see who made the change, the event's name of the change, and the date and time stamp on the far right side of the entry.