Visual Controls Improve Reliability

Visual control is a business-management technique designed to communicate information by using visual signals instead of written instructions.

Properly designed and displayed visual controls enable quick recognition of the information being communicated, resulting in increased efficiency and clarity.

The theory behind visual controls is that, if something is clearly visible and in plain sight, it’s easy to remember and keep at the forefront of the mind. Following the same visual cues helps everyone stay on the same page and provide consistent responses.

There are several techniques and reasons for using visual controls in the workplace. They include safety, materials management, operational status, and “at-a-glance” communications. These devices make the daily control and management of a factory/business as simple as possible. Problems (deviations from standard) are made visible to anyone.

Typically, visual controls consist of visual displays or controls. A visual display relays information and data to employees in the workplace, i.e., team board for decision making, production progress, or quality issues. A visual control is focused on guiding action.

Visual control is also called visual factory, visual workplace, and visual management. My experience and use of visual controls has been in lean implementations such as colors and labels in 5S, color-coding safe walkways, repair areas/material storage, one-point-lessons, and shadow boards for maintenance tools. TPM examples include detecting abnormalities with oil-level markings, visuals to show motor-shaft rotation, gauges in/out of specification, and lubrication points. You want to be able to identify and prevent abnormalities before small problems turn into big problems.

There are many examples in production visual controls. Some are visual height limits for stacked materials, defect location boards, team boards (for deployment of business plans and performance metrics), and on boards and lights (for displaying status and/or notifying team leaders, with a cord or push button that activates a light, sound, or both). As a total plant, visual controls help support standardization, team alignment (by consistency in message) and can improve accountability (through easy-to-understand messaging).

As depicted below by Visual Controls Definition (isixsigma.com), there is a hierarchy of different displays (1 and 2) and controls (3 to 6). This hierarchy can range from simple posters to standard work instructions to a full poka-yoke (mistake-proofing) system.

The hierarchy of displays and controls:

• Information is shared (menu in the cafeteria).
• Standard procedures are shared at a local level (HR bulletins).
• Standard work instructions are posted in the workspace (in easily visible places).
• Problems are identified using devices such as alarms and Andon lights.
• Problems are stopped from moving forward (machine lockouts).
• Problems are prevented.

Visual controls should be used to support your reliability and maintainability best-practices implementation, in addition to your other reliability and maintainability technologies. EP

Based in Knoxville, Dr. Klaus M. Blache is director of the Reliability & Maintainability Center at the Univ. of Tennessee, and a research professor in the College of Engineering. Contact him at kblache@utk.edu.