By drafting in fresh blood and exploiting the savvy of the veterans such as skipper Rory Best, Schmidt has steered his players to three championships in five years.
But following the 24-15 mauling of England on Saturday night, they recorded their fifth victory of the 2018 competition. Only the Irish teams of 1948 – before Italy joined the event – and 2009 have been unbeaten during the northern hemisphere's most prestigious rugby tournament.
The 52-year-old New Zealander hailed his side for their performances during the Six Nations but said they had to maintain their focus if they wanted to be considered as real contenders for the 2019 World Cup in Japan.
"It's incredibly hard to predict," he said. "They are growing and getting better and understanding more but there is still a long way to go for those players."
The triumph at Twickenham – Ireland’s first since 2010 – took them to number two in the world rankings behind New Zealand. It was also a record 12th consecutive success.
"To be honest, we rely still on the same hub of older players," said Schmidt.
"Johnny Sexton, Conor Murray were immense against England, CJ Stander and Peter O'Mahony were fantastic. The newish players though stood out as well
"Youthful enthusiasm is being tempered by the experienced guys who have been here before and that blend is working very well for us."
Best, who has 111 caps, said: "We're really happy. We wanted a Grand Slam and I think we'll look beyond what we want afterwards at a later date.
"The way the younger players have come in and not just fitted in but they have wanted to keep getting better," he added.
"As long as they keep that mentality and the guys who are a bit more experienced keep a mentality of wanting to go forward, that's all you can ask.
"But we'll not know about all of that until our next go in the green jersey. But knowing the group, we'll always want more because we're competitive and we're a little bit greedy."