Already leading 4-0 from the first leg, Bayern cruised into the showpiece at Wembley on May 25 thanks to goals from Arjen Robben, Thomas Muller and Gerard Pique's own goal.
Heynckes admitted that the absence of Lionel Messi from the Barca side helped their cause, but was delighted with how his players followed his instructions and is now looking forward to the all-German final against Borussia Dortmund.
He said: "I think it was clearly noticeable that my team entered this game extremely focused. We played great right from the start.
"My team understood our tactical approach very well and they executed it perfectly.
"Dortmund deserve to be in the final, as they are playing a great season as well. Sure, it's a small surprise that they reached the final. I obviously hope that we can be successful in Wembley.
"I know Spanish football very well, especially Barcelona. I know the way they like to play and their philosophy.
"However, there is no denying it - Barcelona is a different team without [Lionel] Messi. Still, I'm sure no one expected us to win 7-0 on aggregate."
Captain Philipp Lahm is looking forward to toasting their astonishing success and was also quick to pay tribute to his team-mates.
He said: "I'm sure we'll celebrate with a few beers tonight. It's not taken for granted to beat Barcelona on their home ground 3-0.
"But I've always said that we have special characters in our squad and that we are capable of great things."