Sacchi was reacting to Wednesday night's Coppa Italia final defeat to Bologna.
The loss leaves Milan on the brink of missing European qualification altogether with the Rossoneri sitting eighth on the Serie A table.
Sacchi wrote in his column for La Gazzetta dello Sport: "Seeing Milan in such bad shape makes me very sad, because I am tied to that environment, to the fans, to those colors. Watching the Coppa Italia final, deservedly lost against Bologna, confirmed what I have thought since the beginning of this season: Milan is not a team.
"When President (Silvio) Berlusconi hired me, he told me that his goal was to win and to convince. He wanted Milan to put on a show, to entertain people. He had an idea and he knew how to convey it to his collaborators. Does it seem to you that today's Milan, understood as a company, has an idea? It seems to me absolutely not."
Conceicao working in chaos
Sacchi also took aim at the football directors and their coaching appointments.
He continued: "The choice of coach, at the beginning of the season, is fundamental. Milan, on the other hand, last summer first thought of taking (Julen) Lopetegui, and then, given that the fans were angry, they veered towards the Portuguese (Paulo) Fonseca.
"The directors who made this choice made a serious mistake and then, halfway through the season, they thought it best to eat their words and hand over the bench to Sergio Conceiçao, who, in my opinion, is the least guilty of all because he found himself working in general chaos.
"And in the end you will see that he will be the one to pay, because this is an old (and absurd) law of football: out with the coach, so we can sort things out."
Transfer policy makes little sense
Sacchi has also been left unimpressed by Milan's approach to the transfer market, insisting there's little evidence of team planning.
He stated: "Milan is a group of players who were bought at random. I don't discuss their individual technical qualities, even if I could: the problem here is that they are not elements capable of forming a team.
"They go abroad to make purchases, and frankly I don't understand the reason, players arrive who come from different experiences and cultures, you have to try to blend them, but in this way how is it possible to give a style?"