It is always the responsibility of the enterprise to ensure stability of the IT systems that the organisation relies on for its core business.
“The airline also apologised in July after a glitch in its new check-in system caused delays. The system was first installed at airports across the world in October last year, and the roll-out was completed earlier in 2016.”
http://money.cnn.com/2016/09/05/news/companies/british-airways-computer-system-delays/index.html