Apple suggests creating GovtOS would distract several employees from their primary responsibilities for up to four weeks. "Although it is difficult to estimate, because it has never been done before, the design, creation, validation, and deployment of the software likely would necessitate six to ten Apple engineers and employees dedicating a very substantial portion of their time for a minimum of two weeks, and likely as many as four weeks," Erik Neuenschwander, manager of user privacy at Apple, writes in the motion.

These employees would include engineers from Apple's core operating system, a quality assurance engineer, a project manager, and either a document or tool writer. Other people would also be needed to support that team. The group would first have to design and create the OS because it doesn't yet exist, the motion states. They would then implement it by creating an installable image for the suspect's iPhone, which, crucially, would have to be signed with Apple's proprietary cryptographic key.

Once the OS is ready to go, Apple says it would have to put it through its rigorous quality assurance and security testing process. If it finds any issues, which the company says nearly always happens, it would then need to develop and re-code the OS. The cycle of testing would start again after that point. The motion doesn't cite an explicit timeline for this part of the process.

After everything's in working order, Apple says it would have to deploy the OS in its own "secure, isolated, physical facility where the FBI's passcode testing can be conducted without interfering with the investigation or disrupting Apple's operations." This process would take at least a day to set up, not including the FBI's testing time.

It could take even more time to destroy the code after it's complete, and Apple isn't entirely sure the code could ever be completely destroyed. "Even if the underlying computer code is completely eradicated from Apple's servers so as to be irretrievable, the person who created the destroyed code would have spent the time and effort to solve the software design, coding, and implementation challenges," the motion says. "This process could be replicated. Thus, GovtOS would not be truly destroyed."

But the real danger to Apple's resources lie beyond one iPhone. Apple has insisted losing this case would only be the start of routine requests from law enforcement, which would multiply the time and effort required for compliance. If Apple received three orders a week similar to this current one, for example, it would then have to replicate the above process three times a week, every week. "Each such commissioned operating system will need to be tailored to the specific combination of hardware and operating system running on the relevant device," the motion says. There are at least 13 other Apple devices currently subject to court order by the FBI.