Rational Insight Data Services needs to be installed on the systems that host the product data sources. Although all the components of Rational Insight can be installed on a single system, in a business environment these components are usually installed on separate systems.
You need to install Rational Insight Data Services only if you want to read product data from product sources that do not have a built-in XML data service or a RESTful interface. Examples of such products are IBM Rational ClearCase® and IBM Rational ClearQuest®. When you install Rational Insight Data Services, you install the adapters for the products you want to report on. The adapters are needed to expose the data inside the product sources in a format that can be consumed by Rational Insight. If your product sources already have a built-in XML data service, you do not need to use adapters or install Rational Insight Data Services for such product sources. Examples of such products are IBM Rational Quality Manager, IBM Rational Team Concert™, and Microsoft® Project.
If you do not want to install WebSphere Application Server through the installer, you can use an existing instance of WebSphere Application Server.