Seven human factors to consider when developing safety systems

July 11, 2013
People will do whatever they have to do to get the job done, even if that means evading systems designed to keep them safe. Engineers who design safety systems need to keep that fact top of mind. Here are some tips for dealing with the human variable:
1. Understand human nature. It is not enough to rely on industry standards to develop machine safety. You must work with the manufacturing crews. They have so much insight into what people are actually going to do to improve their throughput and efficiencies, even if it requires them to work around safety systems. It's just human nature. By communicating and observing your workforce, you will be able to develop more robust machine safety systems that will still allow for efficiency as well as protect your workforce.

2. Don't invite overrides. When designing a safety system, it's essential to understand how an operator or maintenance technician needs to interact with a machine. It you make the safety system too extreme or complex to deal with, you're actually inviting them to override the safety system in order to get their jobs done. End users should make sure they see a new machine operate with all the safety features functioning before they accept the machine.

3. Safety education. Machine safety is primarily an education issue. Convincing the end customer about the advantages of safety is difficult, but not impossible. Most end users view safety systems as a detriment to production, when the opposite is the case. Good safety principles and finding a vendor who has the products and expertise to assist is 90 percent of the battle.

4. Operator safety. Wherever operator safety is required, you need to ensure that it is foolproof- and mistake-proof system. There's no room for a safety failure because of operator mistake or negligence or bypassing of a few sensors. Also, while interlocking equipment, always consider the adjacent equipment if it is sequence related to the equipment. There have been many incidents of hand injury because the operator forgot to put the adjacent equipment in manual mode before adjusting his machine's setting.

5. Get real feedback. Arrange cross-functional meetings. This means real meetings that have a purpose, where everyone contributes and that result in good documentation. This is key to having a safe approach when integrating controls, interfaces and other automation gear that enhance the workplace. It is easy to create a negative condition when upgrading, especially when it's a poorly supported or poorly organized project. Without representatives assembled to discuss every interacting department's needs (such as training, maintenance, service, emergency conditions, etc.), the project's purpose will not be properly communicated, the buy-in for the change will be seriously impaired and, even worse, unsafe conditions may arise. Bringing their viewpoints into the design review process will help eliminate costly surprises during the testing or rollout phases By conducting proper meetings and maintaining clear communication with all impacted personnel, project management is demonstrated and confidence is instilled in the management of change.

6. Pay now, or pay later. Saving someone from injury by paying for training courses is better than losing production due to an injury or downtime from faulty equipment.

7. Is it needed? Make sure you are on the same page as the machine builder or systems integrator when making design decisions about machine safety. A lot of money can go towards guarding, only to find that the machine will be in a secure area that cannot be accessed during operation. On the other side, the end user should not cut costs by eliminating machine safety features just because they don't understand the need for implementing safety systems.

$afety Pays

The OSHA web site has an application designed for small businesses called $afety Pays that can help make the case for implementing safety systems. It gives scenarios based on lost time (litigation is not included) from the insurance industry, which can demonstrate the effect of severe injuries on sales and profits. http://awgo.to/015
Source: Occupational Safety and Health Administration

Liked this article? Download the entire playbook here

Share this Article

Sponsored Recommendations

MSD-SLC16G

CLICK industrial memory card, 16GB microSD. For use with all products with microSD memory card slot.

C0-12DRE-D

CLICK Ethernet Analog PLC, 24 VDC required, Ethernet and serial ports, Discrete Input: 4-point, DC, Analog Input: 2-channel, current/voltage, Discrete Output: 4-point, relay, ...

C2-FILL

CLICK PLUS option slot cover.

USB-CBL-AMICB6

AutomationDirect programming cable, USB A to microB-USB, 6ft cable length. For use with Productivity1000 and Productivity2000 CPUs and most USB devices.