Safety-specific analysis

Advanced Verification Methods RTCA/DO-254 defines (but does limit to) three advance verification methods which may be used to satisfy the objectives for Level A and B hardware. These are Elemental Analysis, Safety-Specific Analysis and Formal Methods, and are summarised as follows ... 

Safety-Specific Analysis. This strategy focuses on exposing and correcting the design errors that could adversely affect the hardware outputs from a system-safety perspective. Applicable safety-sensitive portions of the hardware input space and output space are analytically determined. The sensitive portions of the hardware input space are stimulated, and the output space is observed not only for the safety-sensitive intended-function requirements verification, but also for anomalous behaviours. The methods of output space observation are identified in advance, by analysis that is accomplished using traditional safety analysis techniques. 

Safe unit placement enhances the overall safety of a pilot plant. A containment cell or a separate building is not, however, a guarantee of safety. Other measures include Increased process monitoring of safety specific variables, limiting inventories of hazardous feedstocks and products, detailed hazard analysis and risk assessments, and good design practices. One essential element is to ensure that the pilot plant has adequate space to support its operation. This requires a careful evaluation of the required space before the unit is constructed. While a detailed layout and a careful... 

This chapter provides a discussion of current security guidelines and regulations (Section 6.2) and a methodology for adapting and applying security vulnerability assessment (SVA) techniques designed for fixed chemical facilities to account for the differences specific to transportation (Sections 6.3 and 6.4). Practical transportation security elements are provided in Section 6.5. Finally, at the end of the chapter, the XYZ Chemical example highlights the unique issues of a security vulnerabiUty assessment as compared to a safety risk analysis. 

ABSTRACT This paper quantitatively analyzed effect of production performance on organizational accidents using Pearson correlation and regression model analysis. Results showed that coal mine output have significant effects on safety. Specifically, this paper posits that there is a U-shaped curve relativity between production yields and accident rate, along with yields increase, death toll occurred in accidents initially decrease, then increase. 

Safety auditors should collect the following safety facilities and non-fmancial information related to the project (1) the written request for the project construction units (2) safety preassessment report (3) safety specific report and relevant documentation about project preliminary design (4) written approval of preliminary design safety fadhties of construction projects (5) the project completion report and related construction drawings (6) the safety assessment report (7) safety faciUties construction project completion and acceptance approval letter (8) technicd indicator information apphes to the audited entity s safety faciUties three simultaneous . Safety facilities "three simultaneous" can be audited by audit, supervision, observation, inquiry, confirmation, calculation, analysis and review and other conventional methods of audit. Due to the comprehensive and technology of safety audit project, safety auditors should also use cost-benefit analysis and economic evaluation of safety and other methods. 

The Inspectorate has a relatively small research and support budget of l-5m per annum, used mainly for special investigations related to licensing and safety matters. It is also used to supplement the expertise within the Inspectorate. The work is contracted out and often specialist outside consultancies are used for specific analysis work. This enables further access to powerful computing facilities apart from those already within house. 

The main challenge that this research work addresses is the selection of a methodology to evaluate the productivity of the manpower of one kind of industry where the work is not representative and the work analysis common techniques cannot be used. Another of the difficulties of the methodology has been the recollection of the data due to the crews work for other companies so that is required to do the necessary adjustments based on the safety specifications of those companies. 

The HEP evaluation is initiated when the human related failure event is placed into the probabihstic model of the system. Then some attributes (factors) of such event are determined according to the procedure of given HRA method / technique. As the result the particular value of HEP is calculated. In the HRA and PSA (prohahihstic safety analysis) screening process only most important and more probable human failure events are taken into account for further context specific analysis. 

Let us comment on the case where a safety specification is not available. Generally speaking, the lawgiver demands that the hazards and risks of the system are acceptable for all stakeholders. He requires that new systems should use state-of-practice technologies for achieving acceptable risks. Based on these principles often safety requirements are specified in standards. If standards are not available, necessary risk reduction measures can be derived from system analysis and quantitative or quahtative hazard and risk analysis (see e.g. lEC 61508). The hazard and risk analysis should consider all potential hazards, for instance, all stakeholders brainstorm on the basis of sufficient system knowledge. 

Software hazard analysis (SWHA) is a system safety analytical technique whose primary function is to systematically evaluate any potential faults in operating system and applications software requirements, codes, and programs as they may affect overall system operation. The purpose of the SWHA is to ensure that safety specifications and related operational requirements are accurately and consistently translated into computer software programs. In this regard, the analysis will verify that specific operational safety criteria, such as failsafe or fail-passive, have been properly assimilated into operational software. The SWHA will also identify and analyze those computer software programs, routines, or functions that may have direct control over or indirect influence on the safe operation of a given system. Also, in the operation of the computer software command function, there is a potential that the actual coded software may cause identified hazardous conditions to occur or inhibit a desired function, thereby creating additional hazard potential. 

A job safety/hazard analysis (JSA/JHA) is a procedure that integrates accepted safety and health principles and practices into a specific task or job procedure. In a JSA/JHA, each basic step of the job is to identify potential hazards and to recommend the safest way to do the job. Jobs that should have JSA/JHA conducted on them... 

Project Safety Clearance and Lean Review This is a summation step with respect to all of the foregoing. The design doeument is reviewed by the environmental, health, and safety group and by the compliance group. Determinations are made with respect to the need for further safety analysis in individual parts of the process or because of their interrelationships. Safety specifications are expanded and become more specific. 

Early in the project when the system requirements are known (not all details need to be known), the first version of the system architecture is known and the first version of the safety hazard analysis is known, it is time for the testing lead to start with the Master Test Plan. In this plan the complete test approach is described. What will be tested, what will not be tested, how thoroughly the different parts will be tested, etc. Note that this plan does not contain information like test design and test case specifications. A thorough description of a (Master) Test Plan is given in (IEEE 1998). 

Functional safety below specification Systematic fault experience Change in safety legislation Modifications to the EUC and use Modification to the overall safety requirements Analysis of operations and maintenance performance below target Routine functional safety audits... 

System Safety Life Cycle Safety Activities System Safety Analyses Safety Trend Analysis Safety Verification Tasks Design Verification Inputs to Specifications Acquisition Tests Operational Tests Safety Tests Inspections Risk Management... 

Software safety requirements analysis The two primary tools for software safety requirements analysis are flow-down analysis and criticality analysis. Flow-down analysis does precisely verify that the proper safety requirements have been communicated to all appropriate parties and that they are correct, consistent, and complete. Checklists and cross-references are frequently used. Europe uses a mathematical modeling tool called/oma/ methods. It is used to specify and model the behavior of a system so that system specifications can be developed. 

A new systems based approach to system safety risk analysis and managemsnt Further development ot the theoretical background and novel melhodolDgias for specific problems. A novel framework using soma existing and some novel methodologies developed. 

Saeed, A., de Lemos, R., Anderson, T. An Approach for the Risk Analysis of Safety Specifications, In Proceedings of the 9th Annual Conference on Computer Assurance (COMPASS 1994), pp. 209-221 (June 1994)... 

Autonomous systems such as robots and unmanned vehicles are widely studied and technically feasible. An important bottleneck for their effective deployment in human environments is the safety concerns of both users and certification authorities. Various ad-hoc safety measures have been designed, often focused on particular risks, such as collision. However, if autonomous systems are to be certified, the method needs to be generalized. We propose here a general method to build high-level safety specifications based on hazard analysis. 

In system safety, inductive analysis tends to be for hazard identification (when the specific root causes are not known or proven), and deductive analysis for root cause identification (when the hazard is known). Obviously, there is a fine line between these definitions because sometimes the root causes are known from the start of an inductive HA. This is why some analysis techniques can actually move in both directions. The PH A is a good example of this. Using the standard PHA worksheet, hazards are identified inductively by asking what if this component fails, and hazards are also identified by deductively asking how can this UE happen. 

A safety engineering analysis of aU tasks in modification or test programs at operational sites. This analysis is specifically oriented toward identifying hazards to personnel and equipment in the work area and is in addition to the analysis of the safety impact of the change to the weapon system. 

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