The document discusses the importance of visual control and transparency to avoid hidden problems. It recommends implementing 5S practices like sorting, organizing and cleaning workspaces to maintain clear visibility. Visual control boards should be used to provide transparency of processes. Periodic audits of employee workspaces and systems can also help ensure nothing is hidden and issues are promptly addressed. Large visual war rooms called "Obeyas" further aid fast and effective decision making through shared information and team alignment. Together these practices of visual control and transparency eliminate hidden problems.