To avoid confusion, the Air France - KLM deal wasn't a merger. After KLM a few years earlier ended talks with BA because management was afraid KLM's influence in the
merger would be too small, they ended up
selling the company to AF.
For very little money compared to the actual value, and with HUGE bonuses and plummy jobs in Paris for KLM's top management.
As
OzzieO says, when it comes to the operational side of things, the 2 companies are run side by side. Thinking behind this is that both brands are valuable, and running them this way will maximise on that fact.
Also, since fringe the benefits for AF employees are hugely better than the ones for KLM employees, and the French (CC) unions are much more powerful and militant than the the Dutch ones, the French unions understandably balk at "equalisation & integration" of benefits.
In the air, little has been noticeable. Small stuff like different drinking cups in tourist class, different OJ and things like that, but nothing major at all.
The companies have removed double flights as it were, so both airlines have lost a few routes to the other, but again nothing major.
Training in both companies is still done very differently as well, with no improvements flowing from one system to the other.
No money to be made on that front, so of course management isn't interested.
Savings are made on the ground, as per
OzzieO. Airport staff, maintenance staff, city offices. Synergy in bulk buying of everything from paperclips to aircraft is a major savings and the resulting profitable airline is a positive thing for the remaining staff.
Of course KLM was profitable before it was bought up, and in the first few years the overall profit came from already lean KLM rather than bloated AF, but it's not considered sporting to mention that fact.
FWIW.