He warned that his own party, Labour and the Tories would all have to compromise on their own separate plans to meet the tight schedule set out by former prime minister Gordon Brown.
The parties pledged that, in the event of a No vote, they would agree a deal on more powers by 30 November – St Andrew’s Day – with legislation to enact the new powers for Holyrood published by Burns Night next January.
“I very much welcome what Gordon has done – I think it’s an excellent initiative,” Mr Kennedy said as he hit the campaign trail in Glasgow’s West End with Scottish Lib Dem leader Willie Rennie.
“I wish it had been done a year ago, frankly, but we are where we are. It is an ambitious timetable, but it’s one we’ve got to meet.
“We have to – if we’re going to command trust and credibility – stick to the timetable. It’s tight, but we’re going to stick to it.”
The Lib Dems support a federal UK, with Scotland being handed major fiscal controls, but their plans differ from the Tory proposals, which include full control over income tax, and those of the Labour Party, which wants further elements of tax and welfare to be devolved.
Mr Kennedy said: “Everybody is going to have to compromise. But an agreed final package has to go beyond the political parties themselves to command widespread approval and endorsement and legitimacy.”
He added: “That’s why you’re going to have to go out to civic Scotland to get their views and you’re going to have to build in the views of the people who voted Yes. That’s vital as well.”