Factory Installers are used to upgrade various machines into their Factory equivalent. Right-click on the machine with the Factory Installer and it will upgrade that machine to a Factory - its level (Basic, Advanced, or Elite) depending on the level of the Factory Installer used.
Basic Factory Installers can be used on any machine that has a Factory associated with it that has not yet been turned into one. However, Advanced Factory Installers can only be used on Basic Factories, while Elite Factory Installers can only be used on Advanced Factories. This is intended so that the player does not skip any links in the "upgrade chain".
Basic Factory Installer
Advanced Factory Installer
Elite Factory Installer