What integrates all departments and functions throughout an organization into a single it system so that employees can make decisions by viewing enterprise-wide information on all business operations?

The answer for the above question is Enterprise resource planning.

This is a process where a company, often a manufacturer, manages and integrates the important parts of its business. It integrates areas such as planning, purchasing, inventory, sales, marketing, finance and human resources. Examples of ERP system modules, include product life cycle management, warehouse management, customer relationship management, among others.