The Plan History allows the user to see all changes and modifications made to a plan.Each modification to a plan will result in a new Revision of the plan (note: in a complex plan there may be hundreds of revisions). If the user is not satisfied with the results of a modification they may go back to any of the previous Revisions and make that instance the active instance (note: this will cause another Revision to be created for the reversion). Below is a walk through and more detailed explanation of this feature.

1. Open the General block from the Plan Overview
2. The summary of the latest revisions will expand to the right
3. Expand the History (this is not mandatory)
   1. The number of plan revisions will be listed (In the above example there are 4 revisions)
4. The user can now review the various revision summaries
   1. Clicking the blue show link will expand that particular version of the plan and explain what was changed
   2. “op”: is the operation performed in this version that differs from the previous version (i.e. delete: an item was deleted)
   3. “path”: is the item in the treatment plan data that had the operation performed
   4. “val”: is the value in the path that had the operation performed
5. If the user would like to return to this version they may do so by clicking the blue make active link
6. The user can close the expanded version by clicking the blue hide link