Reuters Business Report - A staffing fiasco at the London Olympics was a costly one crisis for G4S.
British troops had to step in after the company failed to provide 10,000 security guards.
Another problem was a failed takeover bid for Danish cleaning firm ISS.
Both disasters - combined with other failings - have now led the world's largest security group to part company with its chief executive after eight years.
Nick Buckles was grilled by British lawmakers over the Olympics contract.
The company's reputation with the British government was also damaged by an over-charging scandal.
The Ministry of Justice says it may have paid too much to G4S for monitoring offenders released from prison.
Earlier this month the company issued a profits warning, prompting a 14 percent fall in the share price.
Buckles six years of early success were quickly forgotten
He'll be replaced by Chief Financial Officer Ashley Almanza later this month.
And the company now plans to focus on emerging markets.