''It successfully supports Citibank commercial cards programs across Asia-Pacific and is also used by other Diners Club franchises globally.'' ECS+ replaces ''Daisy'', a system long used by Diners Club Australia, to manage large corporate charge accounts that are settled monthly, that was set to expire by the end of 2010. Because of Diners Club's ease of use for large clients like Woolworths, Coles, and the Department of Defence, it has long been considered a ''cash cow'' businesses, providing organisations easy-to-use cards for hotel, air line, car rentals and cash access, said a source close to the company. Coles were unavailable for comment. Woolworths confirmed last week that it had had problems with Diners Club. The Department of Defence confirmed it has been ''experiencing several service interruptions following a major system upgrade'' and said it was ''working closely'' with Diners Club to ''rectify these issues and expects resolution shortly.''