Safety Review & Certification Services

In line with TÜV Rheinland Functional Safety Engineering, Michael Jackson Controls Limited are pleased to offer our services to review, witness testing at both the factory and the site, and guide automation projects towards certification of the safety functionality.

Background

Concerning Software based safety applications, there are some mandatory steps required to ensure that:

  • It is safe.
  • It complies with the mandatory requirements of the prevailing legislation.
  • The work is compliant with a CE or UKCA certification process.

In the UK a system must achieve a UKCA mark before being adopted.

The standards are often seen as a style guide or a recommendation. However, as you will appreciate in the event of legal proceedings, you would need to demonstrate extremely good engineering reasons for even minor deviations from the standards.

Pre-Requisites

As part of this, we need to undertake due diligence on the project, which requires:

  • Sight of the full risk assessment of the project. 
  • Sight of the formal Functional Safety Specification so that we can prepare the requisite Software Requirements Specification (SRS) and make recommendations for the Safety Related Parts of the Control System (SRP/CS) architecture to ensure that it is compliant.
  • These documents should be written in compliance with ISO 12100:1 (2010) and either BS 13849:1 (2015) or BS EN 62061 (2015).

If the Functional Safety Specification and SRS have already been prepared as part of the project, we would of course need to review these.

Once in possession of these documents, a schedule of further required information can then be prepared.  Typically, this includes the following:

  • safety function(s) provided by the SRP/CS;
  • the characteristics of each safety function;
  • the exact points at which the safety-related part(s) start and end;
  • environmental conditions;
  • the performance level (PL);
  • the category or categories selected;
  • the parameters relevant to the reliability (MTTFd, DC, CCF and mission time);
  • measures against systematic failure;
  • the technology or technologies used;
  • all safety-relevant faults considered;
  • justification for fault exclusions (see ISO 13849-2);
  • the design rationale (e.g. faults considered, faults excluded);
  • software documentation;
  • measures against reasonably foreseeable misuse.

Our Services

We can provide the following:

  • Oversea the validation of library code in accordance with the V model
  • Safety Function Report (per function):
    • Architecture Confirmation (ILO)
    • Safety Circuit Category Confirmation (ie B, 1, 2, 3 or 4)
    • Mean Time to Failure (MTTFd) Evaluation
    • Diagnostic Coverage (DC) Evaluation
    • Common Cause Failure (CCF) Evaluation
    • PL/x Validation
    • Fault Exclusions Reports
    • NB: If proprietary safety components and safety PLC are used (eg. Rockwell, SICK etc), MTTFd, DC and PLactual can be calculated using the simplified approach (BS EN-13849-1).
  • Review of the Factory Acceptance Test (FAT) with mandatory simulation
  • Validation Plan in accordance with BS EN-13849-2 (2012) which includes express documents that align with the validation plan flow chart below:
    • Input Documentation:
      • Design Considerations;
      • Fault Lists and Criteria for Fault Exclusion;
      • Validation Principles
    • Validation Plan
      • Functional Safety Specification and SRS
      • Environmental Requirements
      • Maintenance Requirements
      • Technical Specification & User Information
    • Validation Record
    • Certification
Validation Plan Flow Chart
  • Review of the acceptance of the Site Acceptance Test (SAT)
  • Functional Safety Compliance Report