The textbook purpose of visual controls is “to make abnormal conditions obvious to anyone.” But do your visual controls pass the Sticky test, and compel action?
Simple: Does your control convey a single, simple message? Or does it “bury the lead story” in an overwhelming display of interesting, but irrelevant, information. According to Spear and Bowen (“Decoding the DNA of the Toyota Production System”) information connecting one process to another is “binary and direct.” The signal is either “On” – something is required of “Off” – nothing is required. There is no ambiguity.
Take a look at some of your visual controls. Do they pass the test? Do they clearly convey that something needs attention, or is that fact subject to interpretation?
Unexpected: Why would a visual control need to be “unexpected?” Consider the opposite. Who pays attention to car alarms these days? Yes, they are annoying, but because they so often mean nothing, nobody pays attention to them. We expect car alarms to be false alarms. If your visual control is to mean something, you must respond each time it tells you to. If it is a false alarm, you have detected a problem. Congratulations, your system is working. But it will only continue to work if you follow-through: STOP your routine; FIX or correct the condition; INVESTIGATE the root cause and apply a countermeasure. All of this jargon really means you must adjust your system to prevent the false alarm. Failure to do so will render the real alarm meaningless. It will “Cry Wolf” and no one will take it seriously.
Concreteness: Is it very clear? Do people relate to what your visual control is telling them? Does the Team Leader know that the worker in zone 4 needs help, and that the line will stop in a few minutes if he doesn’t get it?
Credibility: If the condition is worsening, does your visual control show it? Does it warn of increased risk? A typical example would be an inventory control rack with a yellow and red control point on it. Yellow means “Do something” Red means “You better start expediting or making alternate plans because you are going to run out.” Setting the red limit too far up, though, sends out false alarms (see unexpected), and eventually everyone “knows” the process can eat a little into the red with no problem. Why have yellow? What visual control can you put at the yellow line that tells you someone has seen it and is responding to the problem? (Left as an exercise for the reader.)
Emotions: How does your visual control compel action? Does it penetrate consciousness? A few words of warning on an obscure LCD panel aren’t going to mean very much unless someone reads them. How do you get the attention of the person who is supposed to respond? “He should have paid more attention” is the totally wrong way to approach missed information.
Stories: I really connected with this one. Stories are a great way to teach. Simulations are interactive stories. When teaching the andon / escalation process in a couple of different plants we divided the group into small teams, gave them a real-life defect or problem scenario and had them construct a stick-figure comic book that told the story of what would happen. That has proven a great way to reinforce and personalize the theoretical learning.
I will admit that these analogies can be a bit of a stretch, but the real issue is there. Visual controls are critical to your operation because they highlight things that must compel a response.
Your system is not static, or even really stable. It is either improving continuously through your continuous intervention, correction and improvement based on the problems you discover; or it is continuously deteriorating because those little problems are slowly eroding the process with more and more work-arounds and accommodations.
Go to your work area and watch. What happens when there is a problem or break in the standard? What do people do? Can they tell right away that something is out of the ordinary? How can they tell? For that matter, how can you tell by watching? If you are not sure, then first work to clarify the situation and put in more visuals. That will force you to consider what your standard expectations are, and think about responding when things are different than your standard.