There are three levels as shown below.

Level3 - Indicator - Passive warning devices that caution you to perform correctly. Devices that identify a problem after the process, but before exposure to the customer.

Example: Standard Work documents, Inspections prior to the next operation

Level2 - Control - Active warning of the problem as it is occurring during the process. Often requires a human response to be effective.

Example: Alarms, Lights, Control charts, Delete key "Are you sure?" prompt

Level1 - Guarantee - Problem prevented from ever occurring at its source cause

Example: One way assemblies, Automatic calculations, computerized forms that prevent processing with missing data

No copying - Mistake Proofing - Specify the mistake proofing Level(out of three levels from above and see examples) of the following with explanation:

1)Interlocked circuits that automatically lock the car when you change to drive.

2)Automatic sinks in public facilities so the water cannot be left on when someone walks away from it.

3)Auto shut-off irons so we cannot make the mistake of leaving the iron on all day.

4)Traffic Lights on intersections so cars would not crash into each other.

5)Pause-and-serve coffee makers so the coffee stops brewing when the pot is removed.

6)Circuit breakers that trip when they are overloaded.

7)Three-prong outlets so we cannot make the mistake of wrong polarity.

8)Alarms in cars that warn that you left the keys in the ignition.