When more than one version of a drawing exists, the Compare command on the Version History dialog box allows you to view two versions side-by-side and examine their differences. You can compare two versions from inside your own Plant or project database, or you can compare a version in your database to a version in the Plant or another project database. Keep in mind that you can only compare a drawing against a version of itself; that is, you cannot compare one drawing to another drawing.
Differences between drawing versions are assigned to logical "change" groups, which are listed on the Compare dialog box.
Differences also belong to one of three possible categories:
Data — Refers to a mismatch in the properties assigned to an item that exists in both drawings, namely a change, addition, or deletion of a property in the Properties window, in the Engineering Data Editor in Smart P&ID, or through automation.
Graphic — Refers to an item that has changed only in its graphical representation in the design (for example, the item is moved or otherwise graphically manipulated in the drawing).
The following differences are ignored: claim status, select list strings, linked or embedded objects, symbology, and inconsistency indicators.
Adding or deleting an item is also a connectivity change because the relationship between the item and the drawing has changed. Every change grouping and every changed item is assigned a category, and if more than one category applies (for instance, if you move an item and change one of its properties) then the highest priority category is displayed. The order of priority, from high to low, for the categories is connectivity then data then graphic.
The two versions are displayed in two Drawing views, described only as left and right. The relationship between the two views depends on whether you are comparing two versions in your own database or comparing your version to a version in another database.
If the two versions are in the active database, then the left-hand view is the older version, and the right-hand view is the newer version. That is, they are displayed in time-order from left to right.
If the two versions exist in different databases, you cannot be assured that time-order is the logical order to display the versions; therefore, the right-hand view is reserved for the version in your active Plant or project database, and the left-hand view belongs to the version in another database.
You can also compare the differences between the typicals of either drawing. Using the select list situated in the drawing name bar of each view, you can display the primary, typical, or both views of the selected version.
The Compare dialog box in Drawing Manager is useful reviewing differences between versions only. If you want to reconcile anything about the two versions you review, then you must do so inside Smart P&ID modeler. The Compare and Refresh command in Smart P&ID modeler exists for this purpose. If you started with the left-hand drawing version and applied every change listed on the Compare dialog box, then you would end with a drawing that is identical to the right drawing version. For more information about reconciling two versions, see Smart P&ID Modeler Help.