The revision letter
A supplier issues revision D of a component specification. The transmittal says "updated per customer feedback". Somewhere in forty pages a tolerance widened, a material grade changed, or a test was removed. Accepting the revision without knowing which is how nonconforming parts get approved.
What the comparison shows
Upload revision C and revision D. The change list shows each altered requirement with its page number and the old and new text. Tables of dimensions and tolerances are compared cell by cell, and tables that did not change are held out of the result entirely. Repeated headers, footers and document numbers are excluded.
Building it into release
- Compare every incoming revision against the last accepted one before it enters the PLM.
- Store the change list and the redlined PDF with the revision as the record of what was reviewed.
- Use the API to trigger the comparison automatically on document receipt and route changes to the responsible engineer.
Drawings
CAD-exported PDF drawing sheets carry notes, dimensions and title-block text, and those are compared. Changes to line work alone are not text and are outside the scope of a text comparison. The Manufacturing and Automotive industry pages have more on the workflow.
Try it on your own documents. Upload two versions on the homepage. Documents up to 30 pages need no account, and nothing is stored.
Industry page: PDF comparison for manufacturing