Everton are pointless after the opening two games of the season.
Asked whether he was "positive" new additions could be brought in and settled into the squad quickly, Lampard said: "Yes - and quickly and settled-in is not easy. Some teams have made moves in May, June and it was not that simple for us for different reasons. James Tarkowski has been in early and I think you see that in his performances and I think the longer we work - and quickly because I am not giving us too much of a buffer, we want to get results - but the reality is when you are bringing players in maybe there is a tiny 5% of some details that can maybe change games. On another day we could be sitting here with at least two points out of two games. That is not the case but there is a long way to go and I am seeing good things and things we can improve. That is just the work - that is the job."
Asked whether it was "vital" Everton get another striker in, Lampard stressed Dominic Calvert-Lewin was in the process of recovering from his knee issue, while Salomon Rondon did not start against Villa due to his search for match fitness.
He added: "That is something we are looking at to improve because as much as there is real talent at the top end of the pitch... the feeling that we are going to score goals and have that regular goalscoring feel is not quite there."