Explorer

• Introduction
• The Acquisition Lifecycle
  • HFI and the Acquisition Lifecycle
  • Concept Stage
    • HFI Baseline Strategy
    • Target Audience Description
    • Early Human Factors Analysis
    • Domains
    • Concept of Operations
    • Issues Log
    • Analysing Characteristics
    • Comparability Analysis
    • Workstation Design
    • Workload Analysis
  • Assessment Stage
    • HFI Plan
    • Allocation of Function
    • Task Analysis
    • Constraints and Assumptions
    • HFI Working Group
    • Style Guide
    • People Related Requirements
    • Safety Case
    • Health Hazard Assessment
    • Job Design
    • User Modelling
  • Demonstration Stage
    • Solution Providers
    • Through Life Management Plan
    • Manpower Plans and Policy
    • Combined Operational Effectiveness and Investment Appraisal
    • Human Machine Interface Philosophy
    • System Requirements Document
    • Human Reliability Assessment
    • Demonstration and Assessment Report
    • Integrated Test Evaluation and Acceptance Plan
    • Operability Trials
  • Manufacture, In-service and Disposal Stage
    • Lessons Learnt
    • Update People Related Requirements
    • Disposal
• Commercial Considerations
  • HFI COTS Considerations
• Human Factors Assurance
• HFI – Training and Competences
  • Training
  • Competences

Content

Human Reliability Assessment (HRA)

What is HRA?

Human Reliability Assessment (HRA) is a method that involves systematic prediction of potential human errors when interacting with a system.

Once identified it tries to eliminate or reduce their occurrence, in order to maximise safety and performance of the in-service system.

Outcomes of the HRA can be entered into the hazard log and steps taken to reduce the risk to As Low As Practicable (ALARP) by system re-design or implementation of other controls and mitigations.

What should a Human Reliability Assessment Produce?

The HRA should provide an assessment of the level of risk which is based upon:

• Identifying the error types
• Likelihood of error occurring
• Opportunities to recover from error
• Likely consequence of errors.

The assessment should identify outstanding issues with the current design and recommend how to mitigate the errors identified. A review of the Target Audience Description (TAD) report may be appropriate as new information about user limitations are identified.

The HRA should be based upon the tasks and functions specified during an initial Task Analysis. Error identification can incorporate the following techniques and tools:

• Failure Modes and Effects and Criticality Analysis (FMECA)
• Fault and Event Tree Analysis
• SHERPA
• HEART
• Hazard and Operability Study (HAZOP)
• Human Factors Safety Assessment.

What is required to produce a Human Reliability Assessment?

The following lists the information required to produce an HRA:

• Job Design and Manpower Specification
• User Requirement Document (URD)
• Task Analysis
• Allocation of Function
• Workload Assessment.

When should a Human Reliability Assessment be produced?

The HRA begins pre-Initial Gate. A list of issues and risks with recommendations for control and mitigation should be considered before passing the Initial Gate.

Does a Human Reliability Assessment affect any other processes?

The HRA contributes to the Project Risk Register throughout the acquisition process. The others are :

• Safety Risk Management
• Training Needs Analysis (TNA)
• Human Factors Design Processes
• Human Machine Interface (HMI) Design.

Further Information can be found in the HFI Process booklet [PDF], People in Systems handbook [PDF], Def Stan 00-250 and the Human Factors Intranet site.

Change History

Change History

1 March 2010

Further Information amended to include a link to People in Systems handbook.

1 December 2009

Further Information added.

1 March 2009

Updated to include links to other HFI content.