Integrated Safety - or Not! ...Plus 6 Comments; Do You Agree?

08/14/2009


We’ve all heard lots of arguments both for and against a fully integrated architecture for safety and general control. In the process world they’ve maintained a separate SIS (Safety Instrumented System) solution for safety creating a separate layer in their architecture for performing the safety functions. However, in the machine world when PLC’s were introduced in the 1970’s, standards groups rushed to exclude PLC’s from anything safety because the early technology wasn’t very reliable. Guess what happened?

Right, “anything safety” had to be hard wired relegating the safety functions to a separate layer and typically electromechanical devices. This is how the machinery world continued to live until 2002 when NFPA 79 changed allowing hardware / software devices designed, tested, and listed for safety applications. This change in the standard opened the door for options in technology, engineering, and design - to integrate safety - or not!

So, to answer the question today you have to look at your application and consider your options. Also, evaluate your risk assessment, the identified hazards, and what’s required to mitigate the identified hazards to tolerable levels. Layered safety and integrated safety are now options for you to consider along with your company’s safety policy, objectives, and business model.

IT’S YOUR OPPORTUNITY - CONSIDER IT!

Posted by J.B. Titus on August 14, 2009

COMMENTS

September 2, 2009

In response to: Integrated Safety - or Not!fatcat commented:

 

As a designer I agree with the latest comment. As the are three approaches to minimize risk - inherently safe design measures, safeguarding and complementary safety measures, and information for use, the first and most important step in the risk reduation process is inherently safe design, because protective measures inherent to the characteristics of the machine are likely to remain effective, whereas experience has shown that ever well-designed safeguarding may fail or be violated and information for use may not be followed.

September 2, 2009

In response to: Integrated Safety - or Not!Celso Valdez commented:

 

Standars are very good start point to desing, machine, control sistem, SIS etc. Depending of the risk identified and the tolerance allowed by client to the risk and the size of the sistema or machine there are lots of safety devices and solutions to implement. So The core fact from my point of view is safety must be in mind anytime someone desing and contruct any sistem or machine and the new technologies, like smarts devices, control networks, control buses etc have lots of features which when used in accordance with standars can improve safety.

September 2, 2009

In response to: Integrated Safety - or Not!Stan Lichtenberg commented:

 

That is always a hard question. Do you add a PLC to a simple machine just to integrate safety or not? There is no hard and fast line that marks the crossing from 1 to another. But I have seen a PLC added for a couple limit switches and E-Stop buttons. Was that really necessary? In my work I usually am rebuilding older equipment and I present both systems where possible to the customer and let them decide.

September 2, 2009

In response to: Integrated Safety - or Not!Krzysztof Majczak commented:

 

Certainly, it’s always better to have options – one or another.

But from my perspective, the most important achievement of functional safety is introducing standards and methodology to approach safety. Thanks to 61508/62061, 13849 most of guess-work and wishful thinking have been eliminated. The process of DFS (in my terminology – design for safety) eliminates from start most of costly mistakes and makes safety an achievable goal.

September 2, 2009

In response to: Integrated Safety - or Not!haridoz commented:

 

thanks

September 2, 2009

In response to: Integrated Safety - or Not!Steve Ludwig commented:

 

We (Rockwell Automation) agree that the safety solution is dependent on the needs of the machine, which is why we provide a full range of safety solutions including component-based, programmable and integrated safety automation systems.

Machine builders should consider safety a core design function rather than an added function after design is complete. Designing safety and sustainability into the machine reduces risk and improves machine performance.

In less sophisticated applications, simple electromechanical devices may be perfectly adequate. However, more advanced machines can now leverage control architecture that performs multidiscipline control tasks, such as motion and safety in the same controller. These systems use the intelligence and diagnostics of the automation system to operate the machine in the most efficient manner, reducing nuisance shutdowns, waste and energy consumption for the end user, and reducing the design, manufacture, programming and start-up costs of the machine builder.



No comments
The Top Plant program honors outstanding manufacturing facilities in North America. View the 2013 Top Plant.
The Product of the Year program recognizes products newly released in the manufacturing industries.
The Engineering Leaders Under 40 program identifies and gives recognition to young engineers who...
The true cost of lubrication: Three keys to consider when evaluating oils; Plant Engineering Lubrication Guide; 11 ways to protect bearing assets; Is lubrication part of your KPIs?
Contract maintenance: 5 ways to keep things humming while keeping an eye on costs; Pneumatic systems; Energy monitoring; The sixth 'S' is safety
Transport your data: Supply chain information critical to operational excellence; High-voltage faults; Portable cooling; Safety automation isn't automatic
Case Study Database

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.

Maintaining low data center PUE; Using eco mode in UPS systems; Commissioning electrical and power systems; Exploring dc power distribution alternatives
Synchronizing industrial Ethernet networks; Selecting protocol conversion gateways; Integrating HMIs with PLCs and PACs
Why manufacturers need to see energy in a different light: Current approaches to energy management yield quick savings, but leave plant managers searching for ways of improving on those early gains.

Annual Salary Survey

Participate in the 2013 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.

2012 Salary Survey Analysis

2012 Salary Survey Results

Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
The One Voice for Manufacturing blog reports on federal public policy issues impacting the manufacturing sector. One Voice is a joint effort by the National Tooling and Machining...
The Society for Maintenance and Reliability Professionals an organization devoted...
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.