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Human Factors Course

Session 3

Eric DaveyCrew Systems Solutions

2007 March 28

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Session 3 - Design to support human-system interaction

Topics Expectations and challenges Principles and practices Automation Application process

Integrating HF with system design Resources Regulatory expectations Case Study - Therac 25 Medical Accelerator

Introduction

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CLS Mission Expectations

Expectations Excellence in performance Increasing effectiveness and efficiencies Safety and production

Environment Ongoing facility change and evolution Increasing complexity Increasing applications of technology/automation

Background

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Achieving Expectations

Systematic Approach Well defined goals Understanding of hazards and risks Rigourous equipment design Defined practices and processes Controlled operations Ongoing assessment of performance Use of standards and peer guidance Continual learning and improvement

Background

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Importance of Human Performance

Responsibility People design, direct and supervise facility operation

Human Impact Pervasiveness of human involvement in facility operation

Experience Need to provide support for human performance

Background

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Operational Challenges

Gulf

Execution

Goals

Conversion Gulfs

Process StateEvaluation

Activities

Intentions

State

Information

Actions Data

Gulf

Gulf GulfAutomation

Background

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Supporting Human Performance

User Support Principles Environment

Reduce distractions User Accommodations

Reduce memory dependence Simplify tasks Standardize Expect variability Expect errors

Principles & Practices

Recognizing capabilities

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Supporting Human Performance

System Design Principles Conceptual Model Visibility Info completeness & validity Mappings Feedback Affordances & constraints

Shrinking the gulfs

Principles & Practices

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Supporting Human Performance

Operating Practices Pre-job briefing Procedure use and adherence Self-check (STAR) Three-way communication Questioning attitude Independent verification Conservative decision-making

Reducing variability and error

Principles & Practices

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Automation Duties

Application LevelsFacility Processes

Business Processes

Control

Information

Management

Automation

• Closed loop control• Protection• Testing

• Conversion• Presentation• Archival

• Work management• Planning

Automation

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Supervisory Control Challenges

Detrimental Automation Properties Complexity Coupling Autonomy Inadequate feedback

Automation

Automation

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Supervisory Control Principles

Authority Operator must be in command

Process Status Operator must be informed of plant state and trends

Automation Status Operator must be informed about and able to monitor

automation

Automation

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Supervisory Control Principles

Predictability Automation must be predictable

Human Error Automation must be able to monitor operator actions and

intervene when appropriate

Knowledge of Intent To effectively monitor, the operator and automation should

have knowledge of the others intent

Automation

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Automation Principles

Four Groups of Automation Principles General (applicable to all three categories) Category Specific

Control Information Management

Design Principles

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Automation Principles - General

Operator Involvement Design automation and function allocations to promote

meaningful operator involvement

Operator Awareness Use automation to maintain and enhance operator situation

awareness

Ease of Use Provide automation that is easy to use

Design Principles

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Automation Principles - General

Reliance Assume operators will rely on automation if it is available

Backup Provide means to gracefully transition to backup functions

on failure

Training Design automation so that learning to use it is simple

Design Principles

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Automation Principles - Control

Visibility Make the performance and failure of control functions visible

Autonomy Limit independence of control actions

Operating Limits Provide capability for operators to override operating limits

to preserve or re-establish safety

Design Principles

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Automation Principles - Information

Context Present information in situational context

Operator Tasks Provide direct support for operator tasks

Validity of Information Differentiate between valid and invalid indications

Design Principles

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Automation Principles - Management

Operator Tasks Provide support for additional operator tasks beyond direct

supervision and control

Information Exchange Facilitate information exchange and use between systems

Design Principles

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Applying HF - Guiding Principles

Value HF activities must make sense from your business

perspective first and foremost

Emphasis Up-front, pro-active application

Integration HF activities integrated with other project activities

Delivery 80 versus 20 rule

Application Process

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HF Application Model

Planning Analysis Design Testing Use

PerformanceMonitoring

ChangeManagementVerification

Validation

Equipment• Workspace• Interface

Analysis• Contexts• Tasks• ErrorsReview• Experience

Need

Functions• People• Equipment

Application Process

Requirements Implement Commission In-service

Staff & Training• Knowledge• Skills

Goals

Assessment

Application(HF Plan)

Procedures• Content• Representation

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Planning

Planning Analysis Design Testing Use

Need

Goals

Determination of the need and emphasisfor human factors activities

Assessment

Selection of human factors activities,resources, and deliverables

Application(HF Plan)

Application Process

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Analysis

Planning Analysis Design Testing Use

Analysis• Contexts• Tasks• ErrorsReview• Experience

Functions• People• Equipment

Requirements

Describe distribution of functionelements to people and equipment

Describe operating situationsDescribe tasks performed by usersAssess potential for task error & impacts

Identify lessons learned fromprevious experience

Application Process

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Design

Planning Analysis Design Testing Use

Equipment• Workspace• Interface

Procedures• Content• Representation

Implement

Staff & Training• Knowledge• Skills

Input to definition of all design elements• Contexts• Task content• Information needs

Guidance based onproven practice

Application Process

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Testing

Planning Analysis Design Testing Use

Verification

Validation

CommissionConfirm design andimplementation conforms to human factors requirements• Task information• Conventions and standards

A performance test to confirmintegrated system meets operational intent and humanneeds:• Measures• Standards for acceptance

Application Process

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Use

Planning Analysis Design Testing Use

PerformanceMonitoring

ChangeManagement

In-service

Identification and control of system and environmental changes

Ongoing assessment of human performance with system to detect changes from expected performance

Application Process

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Concepts and Standards

HF Concepts Psychology of Everyday Things - Norman The Human Factor - Vicente On Intelligence - Hawkins

Application Process IEEE 1023 NUREG 0711 CNSC Policy and Regulatory Guides

Resources

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Guidance

Interface Design NUREG 700 IEEE series Handbook of Human Factors - Salvendy

Operational Practices Industrial Operators Handbook - Howlett

Procedures Procedure Writing - Principles and Practices

Resources

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Canadian Regulatory Basis

Objective Protect people and environment from man-made radiation

Principles Licensees to prove operations are safe Multiple layers of protection People or technology are not infallible

Regulatory Expectations

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CNSC HF Regulatory Basis

P-119 Policy on Human Factors Safety - Man-made radiation - Environment, People

C-276 HF Engineering Program Plan - Draft Communication of HF application intent

Goals & Scope Criteria & Methods Deliverables and Schedule

C-278 HF Verification & Validation Plan - Draft Communication of assessment intent

Regulatory Expectations

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CNSC HF Oversight Principles

Emphasis Changes and impacts

Beliefs Any aspect of how you do business is a reflection of your

approach to safety Production challenges are a precursor to safety challenges

Review Scope Process Products

Regulatory Expectations

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CNSC HF Expectations

Program Definition Goals to be achieved Rigour a function of safety risk

Scope of Application Organization design Operational practices Workspaces Roles and uses of technology Procedures Staff qualification and training

Regulatory Expectations

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CNSC HF Expectations

Approach Knowledgeable staff Task understanding as basis for design Use of guidance and previous experience HF integrated with other project activities Visibility of HF activities Ongoing regulatory dialog Design verification Operational validation Performance and issue tracking

Regulatory Expectations

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CNSC HF Expectations Documentation

Plans Analyses Design

Equipment, Procedures & Work Practices Assessment

Methods + Results In Service Preparation

Training Commissioning

Regulatory Expectations

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Therac 25 Medical Accelerator

Discussion of mis-operation with respect to human factors issues

Case Study