UK Athletics (UKA) has appointed Neil Black as performance director in the wake of Charles van Commenee's decision to step down as head coach.
Black has been involved with Britain's top athletes for more than 20 years and was formerly UKA's head of sports science and medicine.
One of Black's first duties will be to appoint a new Olympic head coach to replace Dutchman Van Commenee.
He quit after GB missed his pre-Games target of eight medals.
Van Commenee, 54, said "maintaining the culture of accountability" was a key reason for his decision to step down.
Van Commenee leaves behind a reputation of demanding high standards and having a tough approach but Black admits he is tougher than the Dutchman.
"I'm harder in the sense that I will push even further than he did. I want change more quickly. The hardness just comes from confidence and clarity and being sure about what you need to do.
"I am good at clearing up mess. Sometimes someone just has to say, fine I'll do it, and let's get it sorted and then address the cause of the mess," he said.
Black joined UK Athletics as a physiotherapist but has been in charge of performance support services, science and medicine since 2009.
The lead-up to 2012 saw him co-ordinate all support elements for Team GB athletes, managing the support programmes for Olympic heptathlon champion Jessica Ennis and double Olympic champion Mo Farah.
"Charles would go and say you're underperforming and that's great for some and absolutely terrible for others," Black added. "Some people love him for his directness and some people think he's a monster.
"I'll go and say, 'Tell me about your performance', it will take a little bit longer but the end result is the same - they work out their performance isn't good enough."
Black insisted there is no time frame to appoint Van Commenee's successor: "We're looking at number of people, there are some serious contenders out there and some serious British contenders. We won't be hampered by a time factor," he said.
UKA have not had a performance director since 2008 when Dave Collins left the post following the Beijing Olympics.
Former heptathlete Kelly Sotherton says Black is certain to succeed in his new role.
She told 5 live Sport: "Neil is one of those guys you can talk to about anything but he's also very tough, fair and transparent.
"He's a very trustworthy person. I would trust him with my life and I could go to his house on a Sunday afternoon when it was really his day off.
"He works his fingers to the bone. He's a much-liked character but he's also very tough."