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.