Forced Control Mistake-Proofing Devices
Forced control effects are preferred over other forms of
- Wherever possible, use mistake-proofing
techniques that lead to a forced control effect.
- With forced
control, the action or trigger that leads to the effect is both
automatically triggered and compulsory.
There are four families of
devices or methods used to achieve a forced control effect:
- Use of Guides
- Process Control Systems
- These devices do not have to be “high-tech” to work. In fact, many
“low-tech” solutions are more elegant and robust than their
To use Elimination techniques:
- Eliminate decisions.
- Eliminate steps.
To use Combination techniques:
- Combine components.
To create forced control effects via the Use of Guides:
advantage of different shapes in the part.
- First, study the size,
weight, and shape of the part. Then, use one of those
characteristics to develop the guide.
- Keep the shapes simple.
- Check that the guide can only be used one way.
built-in, asymmetrical features.
- Add a new feature or shift/modify
existing features to create asymmetry.
- Trade off aesthetics for
functionality if needed.
- Make sure the guides
- They need to be strong, rigid, and wear resistant.
- Guides should be added to the PM (preventive maintenance) schedule.
If using Process Control Systems:
- Keep the control system
- The control system does not always need to be electronic.
- Mechanical process control systems can be highly effective.
sure that if the control system fails, that it fails in a
- Allow for expandability to accommodate future