Study finds safety is a path to productivity
Good safety is good business. However, this has not always been the case, with many manufacturers generally believing that each investment made in safety had a negative impact on efficiency and productivity.
Today, this view has changed with many top performing manufacturers proving that with contemporary safety automation technology, protection of workers on the plant floor can boost productivity, and the bottom line.
Results of a study conducted by the Aberdeen Group and sponsored by Rockwell Automation showed that companies reporting the lowest injury rates also had the best productivity. The study found that safety, promoted from the top by senior management, was as an essential element of the workplace culture. The report also showed that best-in-class manufacturers rely on advanced safety technologies and carefully calculated procedures to help maintain high levels of workplace protection.
The evolution of safety
Many of today’s legacy manufacturing applications use dated technology and know-how—much of which employs applications developed using a “black box” approach to safety, in which the safety solution was completely separate from the automation system and typically added on after the basic machine was designed, built, and fully functional. Also contributing to this reactive and separate approach were the limitations of safety technology, which often required machines to come to a full stop and be in a “safe state” for repair, maintenance, or any time operator access was needed.
Because these safety systems frequently caused nuisance shutdowns and resulted in unscheduled downtime and lost productivity, operators and maintenance personnel often bypassed or disabled protection systems, risking injuries in the process. This resulted in neither safety nor productivity being fully optimized.
Global and multinational manufacturers are specifying the use of updated global standards to minimize costs, improve flexibility, and achieve consistency. “As a global manufacturer with over 180 locations worldwide, we focus on international safety standards to ensure that machine operators in all locations have the same level of confidence in the machine’s safety system,” said Mike Douglas, General Motors’ senior manager and consultant, Global Health & Safety, Design, Standards and Technologies.
Two of the most rigorous machine safety standards are the International Organization for Standardization (EN ISO 13849-1/2) and the International Electrotechnical Commission (IEC 62061), which the European Union standards bodies (CEN and CENELEC) elected to mandate. This means that machines shipped into or out of Europe had to comply with one of the two standards after the final withdrawal of EN 954-1 at the end of 2011.
The international standards combine two important elements to the definition of the reliability of the machine’s safety function: time and risk, with time being the added element. These two elements help companies take advantage of a more methodical approach to safety system design.
The standards require companies to identify and document the potential hazards associated with a machine and the risk levels the hazards present to users. They also now require companies to document the mean time to probable failure. The safety system is then designed to the level of risk associated with the hazards present on the machine.
The cost of risk
Many companies now include safety as a part of broader, corporate-wide initiatives, including sustainability objectives. Safety executives can take the steps to help increase worker safety, and in turn become more sustainable organizations, helping to protect the company brand.
In fact, sustainable production has become critical to many companies’ success. It is no longer acceptable to consider safety and sustainability as an afterthought or addendum to business practices.
Safety also plays a significant role in a company’s financial risk. Workers’ compensation costs can be a major expense for manufacturers. With effective machine safeguarding and training, at-risk behaviors and “near misses” can be diminished. An effective safety program typically includes measuring and tracking these types of leading indicators. This can have a significant impact on reducing the number and cost of claims or lagging indicators. It also reduces the chance of a fatality occurring since there is a lower frequency of at-risk behavior.
Investing in technology
Traditionally, plants kept safety technology separate from their standard automation control systems. Many manufacturers still embrace this approach and value employing workers whose main responsibility is to monitor and control safety systems. However, this approach generally costs more and creates numerous design and integration challenges.
Manufacturers who employ integrated safety technologies are able to more effectively manage manufacturing risks and streamline standards compliance, without compromising productivity. The Aberdeen Group study found that, although a majority of manufacturers continue to separate the two systems, 47% of the best-in-class are integrating safety with standard control systems. With many recent changes to safety standards and various advances in technology, many manufacturers find it increasingly more efficient to merge safety and standard control systems into a single platform, especially for discrete applications.
Many manufacturers have traditionally used one controller to run standard automation functions, and added safety relays to help protect workers. The relays shut down the entire system in the case of a fault or demand, hampering productivity. With the advent of safety PLCs, many safety relays were replaced. But this left manufacturers with two separate controllers, one for safety control and one for standard control, each with its own software environment, network, and training.
General Motors reduced its cable and labor costs associated with the hardwiring required in safety relays by implementing one controller for standard and safety control. Previously, wiring for a typical five-robot cell required 640 wires and/or cables. With the new system, one five-wire cable is required. One control platform also minimizes the need to manage two disparate systems while lowering hardware, software, and labor costs.
The design productivity benefits of one control platform also led Amcor, a global packaging manufacturer, to implement the solution at its aluminum-can production plant. Previously, standard controllers on the plant’s 11 bodymaker and trimming machines were interlocked with a separate hardwired safety control system. Now, 11 individual integrated safety controllers manage them.
The integrated development environment allowed engineers to develop the standard and safety control system code concurrently, which saved significant time. In addition, with the integrated control architecture already set up, developing and expanding the system is much easier.
The protocol for safety
The Aberdeen Group study found adopting industrial Ethernet as the networking protocol to be a best practice. It allows for a seamless transport of data between safety controls and standard control devices, allowing for increased visibility into safety data. The EtherNet/IP network, for example, allows users to effectively manage real-time control and information flow throughout the manufacturing and IT enterprise.
By using a single, open protocol as the networking backbone for the entire enterprise, users have the flexibility to control, configure, and collect data from any point in the system to help simplify communications, improve productivity, and protect manufacturing systems.
For Amcor, an EtherNet/IP connection provides interlocking between machines and links the controllers to the factory’s SCADA system. The combination of distributed I/O and a CIP safety network helps reduce site installation and wiring time.
See all the data
According to the Aberdeen Group study, best-in-class manufacturers are 43% more likely to have a centralized view of the data from the safety system and plant automation system. Having global access to actionable information about plant operations in real time also helps safety executives at any location make educated decisions. Specifically, the ability to easily extract, share, and use information across an entire enterprise directly from manufacturing assets, such as controllers, helps executives make informed decisions.
Manufacturing intelligence leverages powerful reporting and analysis tools, interfaces, and dashboards to provide critical information and insight, helping manufacturers navigate in a volatile competitive environment. Reporting and analysis tools aggregate essential, real-time metrics and turn them into readily accessible information visible across the enterprise. This empowers executives to understand asset operation, make informed decisions, and improve plant efficiency and productivity. It also arms executives with the real-time information they need to help effectively mitigate risk and improve safety.
Increasingly, manufacturers around the world are recognizing that safety not only helps protect workers, but also increases productivity and boosts the bottom line. The future of safety automation points to even more options and flexibility in applying safety technology to meet specific needs. With the globalization of safety standards and the need to remain competitive in a global market, organizations can no longer afford to view safety simply as a mandatory compliance effort.
Mark Eitzman is safety market development manager for Rockwell Automation.