A well-known term in Lean is Andon. This is a Japanese word and means: lamp.  Andon is a term used for a visual sign that reflects the status of a process.  Traffic lights or stop lights are examples of Andon, as well as sound signals. This is how an Andon light works:
When production goes as planned the Andon shows a green light. When production is delayed, e.g. because of a malfunction, the Andon is orange until the defect is repaired. When there is no production at all and the line has come to a standstill,  the Andon will be red. Clearly indicating that everything is on halt until repairs are made and production can be resumed. VSI have a partner who is market leader when it comes to Andon products and can therefor supply you with an extensive range of Andon items.