WHAT IS SYSTEM SAFETY?

The field of safety analysis in which systems are evaluated using a number of different techniques to improve safety.

There are a variety of techniques each designed to examine a particular aspect of a system with regards to safety.

HOW DOES SYSTEM SAFETY IMPROVE SAFETY?

System safety improves safety by:

• Identifying unsafe parts of a system• Identifying unsafe steps in a procedure• Identifying changes or improvements that could be made to a

system

WHERE IS SYSTEM SAFETY USED?System safety techniques are used in virtually any field and type of company.

At the more complex end of system safety, systems in the space shuttle are evaluated to determine if the space shuttle will work in a reliable and safe manner.

System safety could be a simple as analyzing the steps necessary to perform a task.

THE GOAL OF SYSTEM SAFETY

Hazards are known and controlled to an acceptable level.

Your priority.

• Eliminate or control hazards.• Reduce the potential for accidents and losses.

THE SYSTEM SAFETY PROCESS

Identify each component and operational procedure.

Identify and analyze potential hazards for each component.

Eliminate the hazards by design, minimize effects, revise operating procedures.

• Acceptable risks are judgments made by people responsible for making them (management).

SYSTEM LIFECYCLE

Based off of the MIL Standards

• Concept Definition phase• Development and test phase• Production phase • Operation phase• Disposal

CONCEPT DEFINITION PHASE

• Basic System is roughly designed• Overall system goals and objectives are defined• Develop System Safety Program Plan

DEFINITION PHASE• Preliminary design• PHA• SSHA

• FTA• FMEA• HAZOP

DEVELOPMENT AND TEST PHASE

• Preliminary design• Detailed designs• Critical design review• System testing• Go/no go decision

PRODUCTION PHASE• Product approved for production• Training

• Equipment operators• O & SHA (operating & support hazard analysis)

OPERATION PHASE• Product becomes operational• Safe system operation and maintenance

DISPOSAL PHASE• Disposal procedures

PREVENTION THROUGH DESIGN

Addresses occupational safety and health needs in the design and redesign processes to prevent or minimize work related hazards and risks associated with the manufacture, use, maintenance and disposal of facilities, materials, and equipment.

SAFETY THROUGH DESIGN

Integration of hazard analyses and risk assessment methods into the early design and redesign processes.

Taking actions necessary to so risks are at an acceptable level.

ANSI/ASSE Z590.3-2011

Prevention Through Design: Guidelines for Addressing Occupational Hazards and Risks in Design and Redesign Processes was approved and went into effect in January 2012.

ANSI/ASSE Z590.3-2011 provides guidance on including prevention through design concepts within an occupational safety and health management system.

SYSTEMS TECHNIQUES

There are numerous systems techniques available.

Each has a purpose and an expected analysis outcome.

• Fault Tree Analysis• Failure Mode and Effects Analysis• HAZOP• What If Analysis• THERP• MORT

RISK

PROBABLE LOSSES OVER A SPECIFIED TIME PERIOD

COMPRISED OF THE FOLLOWING:

• EXPECTED LOSS PER MISHAP• ANTICIPATED MISHAP RATE• EXPOSURE TO THE MISHAP

RISK INDEXES

MISHAP RATE• NUMBER OF MISHAPS PER UNIT OF

EXPOSURE

LOSS FROM EXPOSURE• MEASURED IN DOLLARS

RISK INDEX = RATE x LOSS

RANK BY INDEXES• LARGEST RISK INDEX GETS RANKED FIRST

PRIORITIZING RISKS

PROBABILITY

SEVERITY

CAN BE:

• QUALITATIVE• QUANTITATIVE