A visual control shows the current condition quickly.
A visual control shows what the standard is quickly.
A visual control links to an action.
Simply put, a visual control helps Lean companies make a quick, pre-planned decision without guesswork.
A visual control is often used to highlight an abnormal condition.
For example, although rework is an indication of a problem in a process and should be eliminated, in the real world it often exists.
A common visual control has a set number of spaces for defective units. At a glance, anyone walking by can see how many units are in the area and how many spaces are free. The ‘control’ part of visual control means that there is a plan to take action when the last spot is full.
A few final thoughts on visual controls:
The visual control should highlight that a problem exists, even to someone who is unfamiliar with the process.
Use the 10 foot-3 second rule. Make a visual control so obvious that a trained person can tell what is going on by looking at the area for three seconds from ten feet.