IEC 61511 Functional Safety Software

This article explores the main reasons why using IEC 61511 functional safety software is better than traditional approaches, where documents are generated but often not dynamically updated.

The safety life-cycle was a term first used in IEC 61508 [1] to describe the different steps of activity required to develop an electrical/electronic or programmable electronic safety system. Today, that standard is mostly applied when an equipment manufacturer is developing a new safety-related product or system.

A similar safety life-cycle was also framed by IEC 61511 [2]. This one is more applicable to a safety system projects where the equipment from different suppliers is put together to form an overall system used in a safety duty. This IEC 61511 safety life-cycle is the main context for the functional safety software tools being reviewed in this blog.

Do you need specialist software to manage the safety life-cycle?

There is a very short answer to this question, no - you do not need it. However, the story does not end there.

It is possible to manage documents, spreadsheets and "flat file" PDFs like in any other domain. If this is coupled with rigorous document control and regular document update, traditional approaches can work ok.

The challenge is that most organizations are not good at constantly and consistently updating crucial safety information held in different 'flat file' documents.

The challenge is that most organizations are not good at constantly and consistently updating crucial safety information held in different 'flat file' documents.

Specialist software

As you look at typical deliverables for the safety life-cycle, there are clear phases of activity where you may have already selected and purchased some specialist tools which take you beyond what normal office tools can provide.

For example, there are software tools which have been around for some time for recording process hazard analysis (PHA or HAZOP) team findings. Depending on the tool, it might also be possible to extend their use to studies like Safety Integrity Level (SIL) determination using risk graphs or layers of protection analysis (LOPA).

There are also specialist tools aimed at producing bow-tie diagrams, fault tree diagrams, reliability block diagrams, failure mode and effect analysis (FMEA), event trees and possibly others.

What is common to all non-cloud tools is that they apply to a very specific job at a point in the life-cycle, and the main output is a report.

They may have aspects of a database and aspects of automation of some elements, but in most cases they produce a report which gets allocated a version number and each report becomes a "flat file" on a document management system. There is no mechanism for sharing the data in the flat file with other aspects of a project, and no intention of having the safety-related data actually "alive" for operations use.

For example, after a HAZOP, the subsequent documents which get produced later in the life-cycle might copy/paste information from the flat file report, but there is no active or live sharing of captured information as things progress in a project or get updated during operations.

Database or flat files?

It is not hugely surprising that with the advent of cloud computing some companies have risen to the challenge of offering something a little new and different. Instead of just producing dead files, the intent of such cloud-based safety life-cycle software is to embed the use of data in both the project AND operations processes.

Of course the idea of a database is not new, but the possibility of it being cloud-based brings a whole heap of potential benefits. Here are a few:

1. A cloud database with access rights by competency levels means that project collaboration in multi-discipline teams with people from different companies and locations should* be straightforward.
2. With everyone accessing the system in data form, document version control becomes less of an issue provided the software solution supports automated version control and the access rights are set up correctly.
3. When you have moved out of the project phase and into normal operation, a database will represent the "real world" live view of the system, whereas dead files would need very careful review, update and revision control.

*Note: Should? Some software solutions use an intermediary piece of software that allows users to connect remotely to their central service, but this does not necessarily mean that users can work on the same project at the same time!

Where can you get safety life-cycle software?

There are several suppliers who have sprung up from the consulting and engineering world to provide possible solutions.

The following are tools we have used or at least tried:

aeShield - aeShield LLC
exSILentia - exida.com LLC
KISS - Kenexis Consulting Corporation
SafetyInsight - ABB
SISSuite - SISSuite Ltd

Selected Tool Comparison

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Caveat emptor - Buyer beware

So far in this blog, I have sung the praises of potentially employing a safety life-cycle cloud-based software solution.

For real project work, I can give recommendations for some of them, but not all.

If you are interested in why we chose our preferred solution, contact me by filling out your details in the comments below.