Design tools

Implementation is a black box under the user's scope allowance. Compatible software may be installed on the phone after import into the real world.

Specify its required function and hardware interfaces. Physical host, memory, controllers, loading fixtures, cables and power remain explicit wherever needed. A program required during fabrication needs an earlier availability stage; final handset installation cannot power an earlier process.

This boundary is excluded from research-completion percentages and never counts as a natural endpoint.