Wayne Pearse, Consulting Services Team Leader and Safety Consultant at Rockwell Automation explains manufacturers and designers have experienced a substantial shift in safety systems and standards in recent times.
The evolving nature of safety systems requires manufacturers to respond in an appropriate way. Once viewed by manufacturers as simple mechanistic shutdown functions, safety systems have developed into technologies such as safety capable logic, which can react to machine conditions and improve productivity.
To use modern safety systems and standards effectively, manufacturers and designers need new tools. Current international safety standards provide quantitative methods to calculate risk and reliability, a big shift from the simple qualitative approach of EN 954, which did not require designers to assess the reliability of safety components.
There are many compelling reasons to adopt international safety standards including the need to meet the requirements of a global market and lay the groundwork for future expansion.
For instance, machines exported to Europe today must comply with International Organisation for Standardization (ISO) 13849-1 or International Electrotechnical Commission (IEC) 62061.
Manufacturers can therefore take advantage of the framework provided by international safety standards to homogenise the operation of their plants around the world, leading to cost savings in training and maintenance, as well as increased safety for workers and equipment.
The quantitative approaches of ISO 13849-1 and IEC/AS 62061:2005 are also useful for engineers seeking to explain the need for a particular safety system in an application or to justify the cost of a safety upgrade in terms of actual risk reduction.
International standards allow companies to demonstrate compliance to customers and give them confidence their machines will operate safely, with reduced downtime resulting from component failures. This can be augmented by employing engineers who have been certified as a Functional Safety Engineer by industry bodies.
The main consideration for engineers today is to choose a standard they feel comfortable working with and select safety systems that meet the requirements of the operating environment and machine function. International standards not only support global markets and complex safety technologies, but also give designers tools to quantify risk and provide a structured framework to implement integrated safety lifecycle design.
Rockwell Automation held two Safety Automation Symposiums in Melbourne and Brisbane earlier this year to discuss safety standards and trends in designing machine safety applications. The next one-day symposium has been scheduled in Sydney on October 9 and will discuss several key themes of safety standards and systems, including the importance of risk assessments, functional safety in machinery and functional safety calculations.