What Does "Factory Image" Mean?by Dave Maddox
Computers and other devices, such as smartphones, that contain factory loaded software contain a standard operating system and application package called a "factory image." Instead of loading each system from media such as CDs in a step-by-step process for each computer, using a factory image allows quick and consistent delivery of software to each production unit of a particular device model. The "image" is delivered by disk copy or from a network imaging server.
Factory Image Creation
A factory image can be a complete disk or memory image of a file system to be copied into an equivalent space on each device, or it can be a set of software packages to be delivered to a device and installed. Either way, the goal is to produce on the device a predictable system which has been tested at the factory and which can be supported by technicians based on that standard configuration and software.
Device Loading at the Factory
A factory image can be loaded in an efficient and reliable manner onto each device from load servers over a network connection, directly to hard drives before installation, or by a directly wired connection for devices such as phones. Once the software is loaded it will be verified to ensure that the load was complete and accurate. This process can take place for thousands or even millions of devices, all of which will operate the same way.
Restoring a Device's Factory Image
Copies of factory images to restore PC systems are often included as a separate partition on the main hard drive, or on a CD or DVD accompanying the shipped system. For smartphones, factory images are usually made available in single files which contain packaged software or file systems, loaded by a "boot loader" built into the device. Factory images of software updates may be delivered over the wireless network to update all phones of a given type after the release of new software.
Reasons for Using a Factory Image
Even if a factory image is not perfect, it is predictable. It has been packaged, tested, and delivered to many devices. Engineers know what it contains and support personnel can develop a set of procedures, feature lists, workarounds, errors and other information which refer back to the version number of the factory image software. This allows the organization to handle software updates efficiently and to make bug fixes available which address issues in a specific version of software.
Problems With the Factory Image Process
While a factory image is a convenient way to restore a system to a known state, schedule pressures, issues with the factory image creation process, or late delivery of important software can affect whether a factory image is truly the best software to use. In some cases, loading a generic "distribution" version of the system and then adding drivers and other software specific to the target system can take more time, but result in a more robust and bug-free system.