The most important aspect of introducing agile practices is to make sure to include everyone. By everyone I mean every stake holder. Usually in a large corporation you have business analyst who act as advocates for the customers in the field. Then you have systems analysts who act as proxies between the development team and the business analyst. Then you finally have the development team who actually builds the system. When introducing agile you have to make certain not to exclude or take away from given responsibilities that have been there long before you came along.