Many types of business software such as supply chain management applications, ERP systems, CRM applications for managing customers, business intelegence applications, payroll and human resources system typically cannot communicate with one another in order to share. For this reason, such Applications are sometimes referred to as islands of automation or infromation silos. This lack of communication leads of inefficiencies, where in identical data are stored in multiple locations, or straightforward processes are unable to be automated.

Application Integration System is the process of linking such applications within a single organization together in order to simplify and automate business processes to greatest extent possible, while at the same time avoiding having to make sweeping changes to the existing applications or data structures. Applications can be linked either at the back-end via APIs or (seldomly) the front-end(GUI).