Do you know the difference between visual control and visual display? A display tells information, and control prompts some action.
A visual display shares information or standards. It provides the right information, in the right format, at the point of need. Some examples are bin labels to identify different parts or materials, floor markings, safety signs, and defects displays. Work instructions and other types of job aids are also examples of visual display. Bulletin boards to share information like the safety record for the year, open job postings, and changes in policy are a very common visual display.
A visual control calls for action when something happens. The standards are part of the workplace, and a warning makes you notice that something abnormal happened. Sometimes, visual controls not only warn that something happened but also organizes behavior. When an operator pulls an Andon cord, the line stops sending a powerful signal warning of problems in the line. Everybody knows the warning means that the line stopped, and help is needed to fix a problem. The ultimate goal of a workplace is to have visual controls that prevent defects. Mistake proof controls use techniques that make it impossible to make mistakes.
Warning and call for action, organize behavior, and defect prevention are different levels of visual control. A visual display is the first step before you start building visual controls into the workplace. Many companies never moved from this stage, and wrongfully think that they have visual controls. To avoid that same mistake, keep improving one step at a time to reach the ultimate goal, to have mistake-proof controls.