This is something we’ve learned at Clearleft—you can’t create a design system for an organisation, hand it over to them, and expect it to be maintained.
You can’t just hire an agency to create a design system and expect that the system alone will solve something. It won’t do much before the people in the organization align on this idea as well, believe in it, invest in it, and create a culture of collaboration around it.
The people who will be living with the design system must be (co-)creators of it. That’s very much the area we work in now.