Many times I've had the responsibility to retrofit a new design into an existing system for next generation upgrade. My task was to look for an off the shelf enclosure for an electronic control box then design a bracket to mount the control unit into the base of the system.
For the electronic box I worked closely with the electrical engineer to choose components for his schematic design. I found an aluminum enclosure in McMaster-Carr and modified the side panel to mount the electronic components. I then looked for mounting holes in the system and designed a bracket to mount the unit.
Retrofits are very common in the industry for intigration of new upgrades in an existing system.