The Yellow Jackets, touted as an Atlantic Coast Conference championship contender at the beginning of the year, finished a dismal 3-9 campaign with a 13-7 loss to rival Georgia.
After his team dropped nine of its last 10 games, the coach had a blunt assessment: ''Unacceptable.''
''I've got some things I always go through and look at,'' Johnson said after Saturday's game. ''I have some ideas already on what I want to do.''
He didn't get into specifics, but he might be plotting some coaching staff changes after the Yellow Jackets lost five games by seven points or less.
Amazingly, Georgia Tech's only ACC victory was a 22-16 upset of powerhouse Florida State, when Lance Austin returned a blocked field goal 78 yards for a touchdown on the final play. Otherwise, it was a totally forgettable year - a far cry from the 2014 season, when Georgia Tech went 11-3, reached the ACC championship game and routed Mississippi State in the Orange Bowl.
Georgia Tech put up its fewest wins since a 1-10 mark in 1994. And the season saw an end to the school's streak of 18 straight bowl appearances, tied for the second-longest active run in the country.
''It leaves a bad taste in your mouth,'' senior safety Jamal Golden said.
After a brilliant sophomore season, quarterback Justin Thomas took a major step backward. But he wasn't entirely to blame.
The Yellow Jackets had new starters at all the other skill positions on offense. When a rash of injuries hit the B-back position, the drop off was more noticeable. Also, bruising backup quarterback Tim Byerly went down early in the season with a knee injury, depriving Georgia Tech of much-needed depth behind Thomas.
''I don't think he played as well as he played a year ago,'' Johnson said of his starting quarterback. ''But I'm not sure that's all his fault. I think a year ago, he was surrounded by experienced, senior players. This year, he was surrounded by a bunch of young players. At times, there were six freshmen on the field on offense.''
Thomas rushed for just 488 yards after gaining 1,086 the previous year, his average dipping from 5.7 to 3.4 yard per carry. Without a go-to receiver, his pass completions plummeted to less than 42 percent, compared with 51 percent in 2014. In many games, he wound up making costly mistakes simply by trying to do something - anything - to get the offense going.
''Instead of getting a lot of the support and help he got (last season), he was trying to direct and trying to help out,'' Johnson said. ''We didn't protect him very well.''
An experienced offensive line was a major disappointment, as was the defense, which failed to pick up the slack as expected.
At least the Yellow Jackets gave valuable playing time to plenty of younger players, some of whom weren't even expected to take the field this season.
The heaviest losses heading into 2016 will be in the secondary, which must replace all four starters, but Johnson expects more production out of his triple-option offense now that so many players have a year under their belts.
''It's disappointing, but it's all stuff I think we can fix. And I'm hellbent to get it fixed,'' Johnson vowed. ''I'm not going to do through this again.''
Follow Paul Newberry on Twitter at www.twitter.com/pnewberry1963 . His work can be found at http://bigstory.ap.org/content/paul-newberry .
AP College Football website: www.collegefootball.ap.org