The principles of human-centered design apply even if you don't follow the process of human-centered design.
Because... what are the principles?
Well the first one is... uh, be "human-centered." Focus upon the people that, whatever you're doing, it is intended for.
Whether you're doing a service, or a product, or organizational structure, or a new way of stocking a warehouse, or putting things on shelves.
Whatever you're doing, always think of the people.
And all the people.
Not just the people, say, who are going to retrieve the items you put in, but the people who have to put the items up there in the first place.
And if you're in the healthcare system, you have to think about: patients, and their families, and the physicians, and the nurses, and also the medical personnel, and the technicians, and for that matter, even the people who do the scheduling, who clean the place.
You have to think of it as a system and look at all of the components.
That's the second important thing.