EN ISO 13849-1, the quantitative approach to machine safety begins with a qualitative process
EN ISO 13849-1 has now been fully in force since Jan. 1, 2012, without exception and EN 954 has fully been withdrawn. We’ve heard for four years or more that this change in direction equates to a paradigm shift for industry because it in part moves hazard level determination and mitigation from a qualitative process to a quantitative process. There’s more...
EN ISO 13849-1 has now been fully in force since Jan. 1, 2012, without exception and EN 954 has fully been withdrawn. We’ve heard for four years or more that this change in direction equates to a paradigm shift for industry because it in part moves hazard level determination and mitigation from a qualitative process to a quantitative process. There’s more to this story!
It’s true that the Performance Level (PL) system of EN ISO 13849-1 is quantitative based at the completion of the process. I’ve read that the “fathers” of this standard determined that a quantitative approach was needed to both have a direct comparison to the Safety Integrity Level (SIL) system for hazards and to provide the basis for the validation requirements of EN ISO 13849-2. With this system engineers can now calculate the performance level of the safety related parts of the control system (SRP/CS) for each selected safety function. However, this entire process begins (in part) by determining a required performance level (PLr) for each safety function using a qualitative process. In fact, let’s look at the actual 4.3 clause of EN ISO 13849-1 below:
4.3 Determination of required performance level (PLr)
For each selected safety function to be carried out by a SRP/CS, a required performance level (PLr) shall be determined and documented (see Annex A for guidance on determining PLr). The determination of the required performance level is the result of the risk assessment and refers to the amount of the risk reduction to be carried out by the safety-related parts of the control system (see Figure 2).
The greater the amount of risk reduction required to be provided by the SRP/CS, the higher the PLr shall be.
In Annex A you will find two pages that guides you through the qualitative process of asking three questions; severity of injury, frequency of exposure, and possibility of avoidance. Doesn’t this sound eerily like the three qualitative questions used to determine the hazard Categories of B, 1, 2, 3, and 4? The risk graph below looks very similar to the Category graph with the exception of Performance Levels a, b, c, d, and e. The standard goes on to say that the Performance Level (PL) (calculated) must be equal or greater than the PLr.
So, for everyone who has already made the transition to EN ISO 13849-1 – please let us know your thoughts on how much the “fathers” have gained whereas it seems the basis can be argued we are still in a qualitative world of hazards!
Your comments or suggestion are always welcome so please let us know your thoughts. Submit your ideas, experiences, and challenges on this subject in the comments section below. Click on the following text if you don't see a comments box, then scroll down: EN ISO 13849-1, the quantitative approach to machine safety begins with a qualitative process!
Contact: www.jbtitus.com for “Solutions for Machine Safety”.
Case Study Database
Get more exposure for your case study by uploading it to the Plant Engineering case study database, where end-users can identify relevant solutions and explore what the experts are doing to effectively implement a variety of technology and productivity related projects.
These case studies provide examples of how knowledgeable solution providers have used technology, processes and people to create effective and successful implementations in real-world situations. Case studies can be completed by filling out a simple online form where you can outline the project title, abstract, and full story in 1500 words or less; upload photos, videos and a logo.
Click here to visit the Case Study Database and upload your case study.
Annual Salary Survey
In a year when manufacturing continued to lead the economic rebound, it makes sense that plant manager bonuses rebounded. Plant Engineering’s annual Salary Survey shows both wages and bonuses rose in 2012 after a retreat the year before.
Average salary across all job titles for plant floor management rose 3.5% to $95,446, and bonus compensation jumped to $15,162, a 4.2% increase from the 2010 level and double the 2011 total, which showed a sharp drop in bonus.