An enterprise system is a data system that allows to coordinate a company's activities that are performed to achieve its goals. This helps the company to have the information from all the departments in the same place to be able to evaluate it as a whole and make the right decisions.
According to this, an enterprise system is a packaged software application that helps integrate business processes in a company. This is the answer because business processes are a set of tasks that the company perform to provide a product or service to customers which are coordinated using the enterprise system.
The above listed information are part of the reasons why so many IT projects are abandoned by the business entities after a given period of time frame.