A proper error prevention system is built by designing inherently safe and foolproof processes—using constraints, guides, and automation (like dropdown menus and confirmation dialogs) to make errors impossible or immediately obvious. It requires implementing clear procedures, mandatory checklists, and fail-safe mechanisms at critical points to ensure verification before actions proceed. Finally, it must be reinforced by continuous training, a culture of psychological safety where reporting near-misses is encouraged, and regular system audits to learn from incidents and close gaps.