31-Dec-2011 – Are YOU ready?

This entry is part 8 of 8 in the series Cir­cuit Archi­tec­tures Explored

31-Decem­ber-2011 marks a key mile­stone for machine build­ers mar­ket­ing their products in the European Uni­on, the EEA and many of the Can­did­ate States. Func­tion­al Safety takes a pos­it­ive step for­ward with the man­dat­ory applic­a­tion of EN ISO 13849 – 1 and -2. As of 1-Janu­ary-2012, the safety-related parts of the con­trol sys­tems on all machinery bear­ing a CE Mark will be required to meet these stand­ards.

This change star­ted six years ago, when these stand­ards were first har­mon­ized under the Machinery Dir­ect­ive. The EC Machinery Com­mit­tee gave machine build­ers an addi­tion­al three years to make the trans­ition to these stand­ards, after much oppos­i­tion to the ori­gin­al man­dat­ory imple­ment­a­tion date of 31-Dec-08 was announced.

If you aren’t aware of these stand­ards, or if you aren’t famil­i­ar with the concept of func­tion­al safety, you need to get up to speed, and fast.

Under EN 954 – 1:1995 and the 1st Edi­tion of ISO 13849 – 1, pub­lished in 1999, a design­er needed to select a design Cat­egory or archi­tec­ture, that would provide the degree of fault tol­er­ance and reli­ab­il­ity needed based on the out­come of the risk assess­ment for the machinery. The Cat­egor­ies, B, 1 – 4, remain unchanged in the 2nd Edi­tion. I’ve talked about the Cat­egor­ies in detail in oth­er posts, so I won’t spend any time on them here.

The 2nd Edi­tion brings Mean Time to Fail­ure into the pic­ture, along with Dia­gnost­ic Cov­er­age and Com­mon Cause Fail­ures. These new con­cepts require design­ers to use more ana­lyt­ic­al tech­niques in devel­op­ing their designs, and also require addi­tion­al doc­u­ment­a­tion (as usu­al!).

One of the main fail­ings with EN 954 – 1 was Val­id­a­tion. This top­ic was sup­posed to have been covered by EN 954 – 2, but this stand­ard was nev­er pub­lished. This has led machine build­ers to make design decisions without keep­ing the neces­sary design doc­u­ment­a­tion trail, and fur­ther­more, to skip the Val­id­a­tion step entirely in many cases.

The miss­ing Val­id­a­tion stand­ard was finally pub­lished in 2003 as ISO 13849 – 2:2003, and sub­sequently adop­ted and har­mon­ized in 2009 as EN ISO 13849 – 2:2003. While no man­dat­ory imple­ment­a­tion date for this stand­ard is giv­en in the cur­rent list of stand­ards har­mon­ized under 2006/42/EC-Machinery, use of Part 1 of the stand­ard man­dates use of Part 2, so this stand­ard is effect­ively man­dat­ory at the same time.

Part 2 brings a num­ber of key annexes that are neces­sary for the imple­ment­a­tion of Part 1, and also out­lines the com­plete doc­u­ment­a­tion trail needed for val­id­a­tion, and coin­cid­ent­ally, audit. Noti­fied bpdies will be look­ing for this inform­a­tion when eval­u­at­ing the con­tent of Tech­nic­al Files used in CE Mark­ing.

From a North Amer­ic­an per­spect­ive, these two stand­ards gain access through ANSI’s adop­tion of ISO 10218 for Indus­tri­al Robots. Part 1 of this stand­ard, cov­er­ing the robot itself, was adop­ted last year. Part 2 of the stand­ard will be adop­ted in 2012, and RIA R15.06 will be with­drawn. At the same time, CSA will be adopt­ing the ISO stand­ards and with­draw­ing CSA Z434.

These changes will finally bring North Amer­ica, the Inter­na­tion­al Com­munity and the EU onto the same foot­ing when it comes to Func­tion­al Safety in indus­tri­al machinery applic­a­tions. The days of “SIMPLE, SINGLE CHANNEL, SINGLE CHANNEL-MONITORED and CONTROL RELIABLE” are numbered.

Are you ready?

Com­pli­ance InSight Con­sult­ing will be offer­ing a series of train­ing events in 2012 on this top­ic. For more inform­a­tion, con­tact Doug Nix.

Series Nav­ig­a­tionISO 13849 – 1:2006”>Inconsistencies in ISO 13849 – 1:2006

Author: Doug Nix

Doug Nix is Managing Director and Principal Consultant at Compliance InSight Consulting, Inc. (http://www.complianceinsight.ca) in Kitchener, Ontario, and is Lead Author and Senior Editor of the Machinery Safety 101 blog. Doug's work includes teaching machinery risk assessment techniques privately and through Conestoga College Institute of Technology and Advanced Learning in Kitchener, Ontario, as well as providing technical services and training programs to clients related to risk assessment, industrial machinery safety, safety-related control system integration and reliability, laser safety and regulatory conformity. For more see Doug's LinkedIn profile.