After watching his club fall behind early and never recover against Neymar and Co. in the group stage, Rummenigge labelled the match "a very bitter loss" that was uncharacteristic for Bayern.
"It's a loss we have to talk about, we have to analyse, from which we have to draw consequences in clear text form," Rummenigge told FCBayern.tv. "I think what we saw this evening was not Bayern Munich. I think we all agree on that.
"If I take a look to the right or left, then there is nothing to misunderstand or to interpret wrong. I think it's important to turn things around after this loss, to present as Bayern Munich and to show we are a team, [the one] which performed well in Europe and in Germany last year. That's where we have to continue."
Bayern manager Carlo Ancelotti left Arjen Robben, Mats Hummels and Franck Ribery out of his starting line-up against PSG.
All three players had started Bayern's previous fixture – a 2-2 draw at home to Wolfsburg in the Bundesliga – and Ancelotti appeared to take a risk at the Parc des Princes, starting with Javi Martinez alongside Niklas Sule in central defence and James Rodriguez in attack.
But Ancelotti defended his decisions, saying: "I don't think my team selection was risky.
"I thought a lot about what the best team to play was. I know I will get criticism, that's fine. I thought it was a good line-up for this game."
Bayern sit second in Group B, level on points with Celtic, who the Bundesliga champions will face on matchdays 3 and 4. They will visit Hertha BSC in Bundesliga action Sunday.