Do I need to install a specific version of Java in order to use Open Workbench or Microsoft Project with CA PPM?
You do not need any separate Java installation if you want to use Open Workbench or Microsoft Project with CA PPM 13.3 or later.
Since CA PPM 13.3, the installation of the CA PPM Schedule Connect will also include its own "private" JRE (Java Runtime Environment).
The version bundled in CA PPM Schedule Connect will not conflict with any other JRE/JDK version in the system as it will only be used by the CA PPM integration. It is safe for the CA PPM integration to install, upgrade or uninstall any other system-wide available version of Java as long as its private JRE remains untouched.