That TR is useful for finding requirements, but not for a gap analysis, because it does not show if the requirements are equivalent or changed.
Because of the many changes, a
simple gap analysis is not practical. Rather an upgrade approach is best. This method uses a complete clause list for the 3rd edition (e.g.
IECEE CB scheme TRF), with around 1400 line items to check (don't worry, many will be not applicable for a particular device). But, it's still a gap analysis: instead of re-testing everything, you can transfer or refer to the test data in the old report(s) if it fits the new standard, which is often the case.
From experience it usually takes about 2 days to complete the clauselist, after which you should have the "gap" results:
- list of required tests (e.g. new tests in the 3rd ed),
- new documents required (e.g. risk management file)
- non-conformities (design mods necessary to fit the new standard, usually limited to the instruction manual)