When an electronic catalog is revised, not only do the text of the parts lists and the illustrations have to be changed, but also the appropriate links.

A change of the contents (for example, when parts are changed or deleted or new parts are added) can sometimes cause much more effort with an electronic issue than with a printed issue.

In paper documentation, an update leads to changes of graphics, parts lists and maybe a change in the pagination. In an electronic catalog, the links also have to be updated. If a part is deleted, you must check if there are any links inside the catalog that link to this entry. This link must then be changed or deleted accordingly. 

The way such links are created and administrated has a major influence on the financial and timely effort for a revision.