Functional safety capability

Competency stmcture for functional safety During the discussions on lEC standards, it was seen that there should be a responsible authority to implement the safety principles. For organizations, a company safety authority (CSA) is charged with this responsibility. Core principles endorsed by senior management are collectively referred to as strategic competency principles, which are based on a multi-tiered approach to demonstrating functional safety capability. A typical competency pyramid is shown in Fig. VI/1.1-1. There are four strategic competency principles ... 

SILl is relatively easy to achieve especially if ISO 9001 practices apply throughout the design providing that Functional Safety Capability is demonstrated. 

Step 1. Establish Functional Safety Capability (i.e., Management)... 

Whereas Steps 2—7 refer to the assessment of a system or product, there is the requirement to establish the FUNCTIONAL SAFETY CAPABILITY of the assessor and/or the design organization. This is dealt with in Section 2.3 and by means of Appendix 1. 

Full Functional Safety Capability (now called Functional Safety Management) including implementation on a project or product—30 to 60 man-days + several 000 for certification by an accredited body (i.e. SIRA). 

Bringing an ISO 9001 management system up to IEC61508 functional safety capability—5 man-days for the purpose of a product demonstration where evidence of only random hardware failures and safe failure fraction are being offered, 20 to 50 man-days for the purpose of an accredited Functional Safety Capability certificate. 

This involves two basic types of assessment. The first is the assessment of management procedures (similar to but more rigorous than an ISO 9001 audit). Appendix 1 of this book provides a Functional Safety Capability template procedure which should be adequate as an addition to an ISO 9001 quality management system. The second is an assessment of the implementation of these procedures. Thus, the life-cycle activities described in Chapters 2, 3, and 4 would be audited, for one or more projects, to establish that the procedures are being put into practice. 

Adequate functional safety capability is demonstrated by the organization. To include a top level policy, clear safety life cycle describing the activities undertaken, procedures, functional safety audits and arrangements for independent assessment. ... 

The need for Functional Safety Capability (more recently called Functional Safety Management) has been described in Chapter 2, Section 2.3 and also in Appendix 1. lEC 61508 Part 2 (Hardware) and Part 3 (Software) expect this to have been addressed. 

The object is to ensure that all the requirements of the safety system have been met and that all the procedures have been followed (albeit this should follow as a result of a company s functional safety capability). 

In the first case, it is the raft of procedures and work practices, together with the competence of individuals, which is being assessed. This is known as the Functional Safety Capability (FSC) of an organization and is now more commonly referred to as Functional Safety Management (FSM). It is demonstrated by an appropriate quality management system and evidenced by documented audits and examples of the procedures being used. 

Functional Safety Capability (or Management) Assessment (known as FSCA, or FSM). Described in Chapter 2 and catered for by Appendix 1 of this book... 

Showing Functional Safety Capability (FSM) as Part of the Quality Management System... 

This procedure could be part of a company s Quality Management System (e.g., ISO 9001). It contains those additional practices (over and above ISO 9001) necessary to demonstrate Functional Safety Capability as would be audited by a reviewing body (see Chapter 7). 

FSM functional safety management (previously referred to as functional safety capability assessment (FSCA). 

The CASS Guide — Guide to Functional Safety Capability Assessment (FSCA), CASS Ltd 1999... 

To represent the module cooling behavior, it is convenient to define the heat dissipation capability as the ratio of total heat generated to the maximum temperature difference experienced by the switch assembly. This ratio can then be plotted as a fnnction of coolant flow rate to establish the operating range and functional safety margins. Reference [31] shows the heat dissipation capability of the heat sink assembly. 

The detailed functional safety requirements specification should include all necessary functions during all modes of operation of the process being protected. Additionally, the periodic testing of all the safety instrumented functions should be provided. This typically requires the definition of maintenance override capabilities so the sensors and final elements can be tested without shutting down the process. The same methodology described in the paragraph above can be used to document these requirements. 

Confirm feasibility regarding human capabilities performance and reallocate inappropriate tasks to equipment (i.e tools, automation etc) as functional safety requirements. 

NOTE 2 Adequate independence means that neither the failure of any non-safety functions nor the programming access to the non-safety software functions is capable of causing a dangerous failure of the safety instrumented... 

In recent years, there has been a dramatic increase in the deployment of software in safety-related and safety-critical systems. If we consider a specific category within safety-critical systems for illustration, military aircraft, it is evident that the ongoing requirements for increased functionality and capability have resulted in dramatic growth in the number and complexity of avionics and mission systems in order to provide air superiority over potential adversaries. These mission systems include, but are not limited to, head-up displays (HUD), digital map displays, sensor systems, retina-tracking target-designation systems, and electronic countermeasures systems. 

Typical hypothetical accidents were analyzed to demonstrate the passive safety capability of the 4S-LMR. The accidents analyzed were chosen to demonstrate whether or not the passive heat removal capability and the passive reactor shutdown capability play a significant role [XV-5], The term passive reactor shutdown does not mean a true shutdown but a function of reducing the reactor power to a level where heat removal can be accomplished passively with the use of the RVACS and with no core damage. 

The HVAC system for the control room area is designed as seismic category I and will result in loss of system functional performance capability in the event of loss of offsite power concurrent with safety shutdown earthquake. The system ductwork is leak tested in accordance with ASME N509. 

Capability to design, operate, and maintain for functional safety Establishing competency Hierarchy of documents... 

Paragraph x of the Quality Manual emphasizes that capability in respect of functional safety is a specific design capability within XYZ Ltd. Some contracts will relate to safety-related applications. Some developments will specifically target safety-integrity conformance as a design requirement. 

Eurthermore, the research project shall proof the capability of a proven in use approach on the basis of the identified field data. Thus, a complementary procedure to the EN ISO 13849-1 could be developed, that is able to support the manufacturers of machine tools with a quantitative calculation of the Functional Safety that complies with the standard. 

Nunns, S.R., Prew, R.W. Safe and sound Achieving organizational functional safety certification for lEC 61508 and lEC 61511. Special Report on Process Automation Services Capabilities ABB Review (April 2(X)8)... 

Conformity Assessment of Safety related Systems. Refers to the developing methods for assessment of project execution, equipment design as well as Functional Safety Management Capabilities. In the UK, accredited certification bodies will be available at a future date to offer CASS assessment services to industry. 

Pyrotechnics have been used for military purposes for many centuries as propellants, explosive charges, time fuses, and for illumination. There are still many uses of pyrotechnic devices in military appHcations, where they provide portability, storage stability, simplicity of operation, safety, and the reUability required for military scenarios. The devices must be capable of surviving rough handling, weather extremes, and extended storage, yet reUably perform when called on to function. 

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