The old way of doing things is over.

Dave Gettleman, for the first time as the general manager of the Giants, will meet with all the team’s scouts Tuesday when they convene for Senior Bowl week in Mobile, Ala. Gettleman will lay out the comprehensive, sweeping changes about to hit an organization that can trace its demise to failures in identifying and procuring enough quality players.

For those concerned the hiring of Gettleman, a longtime Giants personnel executive, was counterintuitive to the “wholesale changes” mandate co-owner John Mara set forth for a franchise that has one playoff appearance in the past six years, rest easy. Gettleman, The Post has learned, is tearing up the Giants’ entire operation when it comes to the draft — from how players are graded, how scouts will be assigned and how the actual draft board is assembled.

“We’re changing everything around in the department, from how we operate to the grading scale, everything,’’ a Giants source familiar with Gettleman’s thinking told The Post. “Everything. Nothing’s going to stay the same.’’

Gettleman, 66, spent 15 years working in personnel with the Giants, but his NFL apprenticeship was served elsewhere, starting as an intern in Buffalo in 1986 and later as a scout for the Broncos. After leaving the Giants, he spent four years in Carolina as the general manager of the Panthers. The new template he will unveil was created with ideas gleaned from all these stops.

“We’re gonna have what I call a philosophical and method shift on how we operate, yes,’’ Gettleman told The Post. “The philosophy is the way of looking at players, and the method is how we set up the draft board.’’

With the Giants owning the No. 2 pick in the upcoming draft, it is imperative Gettleman gets it right — not only the first-round selection but also the mid-round players who were so hit-and-miss under Jerry Reese, who was fired Dec. 4.

One of Gettleman’s first moves was to dismiss Marc Ross, the vice president of player evaluation — meaning, for this cycle, Gettleman will run the entire draft operation, which Ross oversaw the past 11 years. Gettleman has elevated Chris Pettit, a scout for the Giants since 2004, into an organizational role within the office for this pre-draft process.

Reese was a Giants scout before he rose through the ranks to top-executive status, but in recent years he increasingly distanced himself from his area of expertise — perhaps wanting to stay closer to the team facility with a young head coach, Ben McAdoo, in place. He attended few college games the past two years.

There were some in the building who wondered why Reese did not at least drive down to Rutgers on game days to check out the Big Ten prospects on the field, or why Reese saw the need to watch a Giants walk-through on a Saturday when there were college games to see on various campuses.

Gettleman knows all the Giants scouts, so this will be more indoctrination than introduction; what is presented to them will be eye-opening. Under Reese and Ross, the Giants were often drawn to height-weight-speed prospects who too frequently went bust rather than boom. It is believed Gettleman will bring the emphasis back to production on the field — stressing passion, desire and mechanics rather than raw talent.

This will be reflected in how players are actually placed on the Giants’ draft board. Gettleman took a look at how the Panthers graded players, preferred that system to what he knew with the Giants, and retained it in Charlotte. Now he is bringing it to the Giants.

“Putting your focus on different things, the board is gonna look very different,’’ Gettleman said. “It’s actually something I learned in Carolina. There’s an old saying: Every man is my equal, in that I may learn from him. These guys taught me a different way of looking at it — not how to evaluate, not how to do it philosophically, but just a different way of setting up a board, and I think it’s terrific.’’

Gettleman would not get into specifics, but agreed the new draft board will more accurately display how an individual players’ grade relates to others on the board.

“It gives you not only a vertical view but also a horizontal view as well,’’ he said. “It allows you to really see the board, without giving anything up.’’

All NFL teams — other than the Patriots, not surprisingly — hire one of two scouting services, National Football Scouting or Blesto, to get a better handle on college juniors. The Giants are with Blesto. Teams usually assign one of their young, inexperienced scouts to these services, and one of Gettleman’s first jobs was as the Blesto scout for the Bills. When Gettleman got to Carolina, one of his first moves was to switch the Panthers from National to Blesto.

“You got to realize we’re all gonna go back to our roots,’’ he said.

If it is not broke, Gettleman sees no need to fix it. The way the Giants added talent through the draft is broken, though, hence the need for a fix.

The Giants’ college evaluations for this year were quite advanced by the time Gettleman was hired, but, in time, it is expected he will make adjustments in the way the scouts move across the country in search of talent.

“I’m not going to address any of that stuff until after the draft,’’ Gettleman said. “What I’m trying to do, time is of the essence here, there are ways of implementation that create the least amount of angst and confusion, and that’s the path I’m taking.’’

The Giants, unlike several teams, do not have regional or national scouts. Giants scouts are assigned to work specific areas of the country, with Reese or Ross supposedly serving as an “over the top’’ scout to put an extra set of eyes on the “A” rated prospects, wherever they may be. The Giants’ system had holes in its exposure, and Gettleman will attempt to close up those holes.

Gettleman, according to a Giants source, wants more checks and balances, as it is his “bugaboo’’ that there are many players the Giants rated as “C” level prospects thriving in the NFL with other teams.

“My goal here is to just to do a better job to improve the evaluation process, to make it more concise, make it more clear as to the types of players we are looking for and we want to draft,’’ Gettleman said.

Is he confident this will clear a pathway to bring in better players?

“That,’’ Gettleman said, “is the goal.’’