Mistake-Proofing Resource Center

Sensory Alert Devices

Sensory alert solutions can make it easier to know when to take action to prevent an error or when to act on a defect.

  • These solutions require the operator to see the alert and then react to it.

Sensory alert effects can be achieved from techniques such as Color-Coding, MIA (or missing-in-action), and Sensory Alert Aids.


  • When using color-coding, the presence or absence of a color or conflicts in color can help to prevent errors or to make it easy to pick out an error should one occur.

MIA (missing-in-action)

  • MIA techniques are intended to draw a person’s eye to where something belongs or where something is missing.

Sensory Alert Aids

  • Aids are simple sensory alert techniques that help a person do the job right. Aids include diagrams, pictures, checklists, and 5S techniques.

Tips when using sensory alerts:

  • If you use color-coding, make sure the colors stand out.
  • If you use sensory aids, keep them simple.
  • Don’t underestimate the power of the 5Ss as a sensory alert aid. For example, spills are always an important alert of something going wrong.