Robert Agcaoili, with a realization in the midst of some OmniFocus maintenance:
A versatile system allows subtle to drastic changes without ruining the integrity of it. […]
So when thinking of implementing a system in your life, not only should you make sure you have room to expand, but that it is structurally rigid to not completely fail you in its growth.
A trusted system one that’s sustainable. With a little bit of care and maintenance along the way, it should grow with you as your responsibilities evolve.