Pochettino is a coach who understands strategy and is able to build a better quality team. He has worked with Tottenham for several seasons and he has also worked with PSG. Pochettino will slowly restore the quality of Chelsea's game in the Premier League so they can compete again for the title. His initial job was difficult because he had to build Chelsea very carefully, his experience can help him to speed up his recovery.
We all know that Pochettino is a professional coach, he must understand tactic/strategy. But Chelsea is not the same as Tottenham or PSG, this team is quite complicated. He may be successful to improve Tottenham or can win the titles with PSG, but I'm not sure it will be easy to rebuild Chelsea. There are too many top coaches who failed to rebuild Chelsea, it has too many problems. However, seeing the current performance of Chelsea players under his management so far, we can expect Pochettino has a chance to improve Chelsea. I think it is too early to expect competing for the title, we only expect Chelsea to return to the top 5.
Pochettino's plan for Chelsea is very clear, he wants to return Chelsea to the peak of its performance. But I hope Pochettino won't swallow his own saliva after making that statement, it's because Chelsea have a lot of players who still haven't fully adapted so far.
Of course, the goal is clear, he wants to make Chelsea stronger. That's why he rebuild the squad, he bought some new players and sold unnecessary players.