System Safety Management
The Basic Need For Safety
• Originates as a fundamental human need
• Dr. Abraham Maslow outlined a hierarchy
• States that humans are motivated to action by
unsatisfied needs
• Physiological needs are first:
– Air, Water, Food, etc.
• Basic requirement must be fulfilled before there is
interest in a higher function
Hierarchy of Needs (cont.)
• After Physiological needs are met Safety concerns
are second
• At this level humans seek stability in their lives
• Freedom from hazards or potential threats
• In this layer humans predominantly seeks structure
and order
• Comfort zones are developed based on boundaries
and known parameters
Human Need for Safety
• Safety needs are mostly psychological in nature
and difficult to quantify
• Perception of safety is often based on false
assumption and intuition
• Once the “feeling” of safety is achieved humans
can move on to the next tier
• Higher tiers relate to increased efficiency and
higher personal performances
Human Needs Based on Deficit
• Homeostasis principal (deficit needs)
– Thermostat / Furnace relationship
• Human needs are essential to survival and
instinctive or instinctoid
• Needs are Prepotent -- our actions are influenced
by our greatest need
Industrial Revolution
• Significant steps in structured safety efforts
evolved during this period (19th Century)
• Safer practices met personal needs and was
eventually considered “Good Business” as it
protected skilled laborers and valuable
equipment
• Safety Programs proved to be a Win-Win
solution
Anonymous Safety
Professional statement:
“It is immoral to design a
product or system for mankind
without recognition and
evaluation of the hazards
associated with that product or
system”
History of Safety Process
• To best enable users of system safety practices to
understand the process of safety, placing today’s
programs in context to their historical
predecessors helps maintain the lessons learned of
their “safety forefathers”
• System safety began within the context of looking
for safe results
Aviation Safety Process - 1908
• Aviation safety processes can be traced back to the
earliest days of aviation when a mishap occurred
during flight demonstration of a new aerospace
system (Wright Flyer) at Fort Myer, Virginia
• The investigation revealed that an untested subsystem (propulsion) component (propeller), failed
causing subsequent damage to the other propeller
and structural supporting guy wires
September 17, 1908
First Aviation Fatality
Mishap Investigation
• The sub-system, which had performed reliably,
was modified in order to successfully meet and
exceed US Army speed specifications
• The designer (Orville Wright) had extended the
previously proven propeller design by
approximately 4 inches
• This untested modification failed, striking the
other propeller and a wire bracing the tail section
causing it to collapse and pitch into a fatal plunge
Fly-Fix-Fly Approach to Safety
• This type of flight research was consistent with the
approach that produced a functional aircraft
• The Wright Brothers had successfully
accomplished powered flight with a trial and error
approach to flight testing their new designs
• There were few previous studies for them to
review -- Each flight was an experiment, if a new
design worked, they would fly it to gather data. If
it failed, they studied the deficiencies; performed
modifications and flight-tested the new design
Science of Accident Investigation
• Early flight posed new challenges, which shaped
safety programs that grew to address hazards
• During these formative years the complexities of
aircraft and the effects of the environment in
which they operated were not fully understood
• Inquiries into aircraft accidents were not
specialized enough to capture information in a
fashion that identified all the hazards, eliminated
them or reduced them to acceptable levels
The Need for System Safety
The first fatal powered-aircraft accident
investigation pointed to the need for system
safety practices – the formal recognition of
this holistic approach came decades later
Aviation Safety Programs
• The US Army Air Service took the first steps
toward a formal aviation safety program in 1921
• The Chief of the Medical Division --Air Service
reviewed all accidents that caused injury to people
or equipment during the previous year
• In that report the first soundings for a formal
safety program were heard
Chief of Air Service 1921 Report:
“…that the Air Service desires to perfect preventive
accident measures to the fullest possible may be
readily appreciated from the fact that during the
calendar year 1920, 51 officers and enlisted men of
the Air Service lost their lives in airplane accident,
[and] 312 airplanes were damaged or destroyed...”
Systematic Approach
• In December 1925, the Commander of the
Information Division of the Air Service, Major
Henry H. “Hap” Arnold, identified the need for a
systematic approach to aircraft maintenance and
operations
• His interest was in determining what constituted an
effective maintenance program
• Examining the most successful flying operations,
then identified and recognized the best practices
Organizational Best Practices
• The best organizations with the most reliable
aircraft had:
– Written instructions for crew chiefs
– Work stands, which allowed better access to
work areas
– A system of supervising inspections
• Also recognized were human performance issues:
– Poor pilot training
– Inadequately trained maintenance personnel
Technical Report - 1927
• The Inspection Division Accident Committee
undertook a comprehensive review of the newly
designated Army Air Corps accidents from 1917
to date
• The Development Section’s solution to the
“accuracy problem” was the creation of the
Technical Report of Accident Classification
committee
• They were specifically chartered for accident
prevention and could not be used for legal
purposes
NACA Report -1928
• The National Advisory Committee on Aeronautics
addressed the other two problems that same year
in a report labeled simply as #308
• This report set standards for:
– Accident terminology
– Classification analysis
• Creation of standardized flying hour tracking
forms
Challenges To Improving The
Safety Record
• Inconsistency of accident reporting procedures
• Decentralized control of trends and analysis
• A conflict between the US Army’s competing
priorities of accident prevention and personal
accountability for such accidents (Retribution)
Army Air Corps Accident
Investigation Goals -1930
• Sought to improve materials
• Identify improvement to training programs
• Proper budgeting for procurements and
spares
Reactive Safety Program
• Emphasis was placed on the accuracy of
information input into data base
• Program fell short of a definitive process that
allowed data to be analyzed and transformed into
preventive actions (information & knowledge)
• Accident prevention efforts were mainly
characterized by an emphasis on what happened
• “Rear view mirror” study of a threat and reactive
in nature
Air Commerce Act - 1926
• Air Mail delivery provided the first commerce
sector for aviation - “the mail must get through”
• By 1930 this new career field was recognized as
extremely perilous
• Between 1933 and 1936 Congress held 26
separate investigations into various aeronautical
concerns
• Accident frequency had a negative impact on
public confidence in aviation
Public Confidence Eroded
U.S. Army Safety Section
• Keenly aware of Congressional concerns the U.S.
Army institutionalized accident prevention as a
distinct discipline
• Captain Samuel Harris was first to lead the new
safety organization within the Inspection Division,
formed in 1940
Safety Section Duties
• Develop systems for the purpose of improving
standards of operations and maintenance
• Conduct studies of unsatisfactory performances
• Provide statistical studies of accidents, incidents
and equipment failures
• Maintain a confidential file on personnel showing
a history of accident/incident involvement
• Analyze and prepare studies of damage reports
and accidents
• Recommend changes to promote efficiency
U.S. Army Air Corps Safety
Culture
• Statement of responsibilities highlight a
maturation in both structure and direction
• Established accountability for the reorientation of
safety efforts from merely identifying and
correcting “unsafe situations” to a “proactive
posture”
• The Commanding General of the Air Corps
created an institutional culture with mishap
prevention as a core responsibility
Safety Objectives - 1941
• Developed a multidisciplinary approach to air
safety
• Creation of a holistic, analytical view of accidents
• Apply accident analysis (lessons learned) to
prevention efforts
• Measurement of effectiveness of prevention
(Taxonomy or Performance Metrics)
U.S. Army Air Force - 1942
• Head of Safety Section elevated to Directorate
status
• Director of Flying Safety now equivalent to a
Deputy Chief of Staff
• Historical basis of safety reporting directly to the
top of the organization established
• Colonel Harris reporting directly to the
Commander-in-Chief
Office of Flying Safety - 1945
• Organized into 5 functional areas
– Training and Operational Policy
– Material and Maintenance (concerned with lifecycle related aircraft problems)
– Medical Safety (tracked human factors and
personal equipment issues)
– Safety Enforcement (monitored violations)
– Safety Education ( safety material and training
manuals)
Modern Day U.S. Air Force
• All of the functional areas addressed by the 1945
Office of Flight Safety have analogous functional
areas in the present day USAF
• Compared to modern day system safety
methodology, this systematic approach identified
and acted upon by General Arnold and Colonel
Harris readily illustrate the genesis of the “safety
of the system as a whole” vision which grew into
present day system safety programs
The Key to Program Success
• The vision and willingness to direct, from the top
down, is clearly identifiable as the critical element
to the success of early USAF safety programs and
remains, to this day, a vital key to any programs
success
• “There is no substitute for genuine top-down
commitment to insure a safety program’s success”
System Safety in the Civilian Sector
• The first recorded presentation, to the aviation
industry, of a system safety processes was by
Amos L. Wood in New York in January 1946
• His presentation was titled “The Organization of
an Aircraft Manufacture’s Air Safety Program”
• Mr. Wood emphasized continuous focus of safety
in design, post-accident analysis, safety education,
accident preventive designs that minimize
personnel errors, and statistical control of postaccident analysis
Engineering For System Safety
• In September 1947, another paper was published
by William Stieglitz entitled “Engineering for
Safety”
• His work outlined a vision for system safety
• He stated, “Safety must be designed and built into
airplanes, just as are performance, stability, and
structural integrity...”
• “...A safety group must be just as important a part
of a manufacture’s organization as a stress,
aerodynamics, or weights group….”
Engineering For System Safety
(cont)
• “Safety is a specialized subject just as are
aerodynamics and structures’
• “Every engineer cannot be expected to be
thoroughly familiar with all developments in the
field of safety any more than he can be expected to
be an expert aerodynamicist”
Engineering For System Safety
(cont)
• Amos Woods went on to state, “The evaluation of
safety work in positive terms is extremely difficult.
When an accident does not occur, it is impossible
to prove that some particular design feature
prevented it”
System Safety – An
Interdisciplinary Practice
• Thus the formal connection between system safety
and aviation advances were forged
• These farsighted visions comprise the basis of
current system safety programs both in aviation
and other disciplines, including medical science,
atomic energy and even industrial hygiene
• All evolved due to viewing the whole system and
any interacting parts in an interdisciplinary
approach
Air Force Performance Metrics
• 1946 safety statistics reflected an unsatisfactory 83
accidents per 100,000 flying hours
• By the mid-1950’s this was reduced to 10
accidents per 100,000 hours
• Current day standards hover in the 1.25 to 1.75
range and have been on a plateau for 15 years
Public Expectations of High Standards
• In some things, public
confidence demands a
proactive posture
• Waiting for a mishap to
point out design
deficiencies and latent
hazards is economically
and ethically
irresponsible
• A “Fly-Fix-Fly”
philosophy is
unacceptable as a means
to identify, analyze and
control hazards
Systems Safety in Acquisition Programs
• During this era the
USAF was actively
managing several
system acquisition
programs including
ICBMs and the first
phase of a research
airplane program
seeking high-speed
flight, beyond the
speed of sound
Industry “Best Practice”
• In 1950, the USAF Directorate of Flight Safety
Research (DFSR) was formed at Norton Air Force
Base, California
• By 1954 the DFSR began sponsoring Air Forceindustry conferences addressing safety issues of
various aircraft systems by technical and safety
specialists
• Recognizing best practices, the USAF lead was
soon followed by safety centers for the US Navy
in 1954 and the US Army in 1957
Industrial System Safety
• Safety stems from personal needs and business
requirements for greater efficiency
• The first four decades of powered flight proved a
“rear view mirror” approach to safety was
ineffective and expensive
• In lieu of trial and error, military leadership
stressed a systematic discipline, focusing on
proactive efforts, seeking to identify hazards,
analyze them for risk and controlling them as
known quantities
Industrial System Safety (cont)
• The focus is to establish an acceptable level of
safety, designed into the system as a whole before
production or operation
• This approach seeks to perform identification and
evaluation of hazards before an incident or
accident causes a loss
North American X-15
• Joint USAF/USN/NASA
Research project covering
5 years and 120 space
exploration flights
• Managed by USAF
Systems Command
• The most successful
“Systems Managed” space
exploration program
• 92% mission success rate
System Acquisition
Specifications
• In July 1960 a system safety office was
established at the USAF Ballistic Missile Division
in Inglewood, California. They published the first
system-wide safety specification titled BSD
Exhibit 62-41
• The Naval Aviation Safety Center was the first to
become active in promoting an inter-service
system safety specification for aircraft, using BSD
Exhibit 62-41 as a model
System Safety Culture
• By 1962, system safety was identified as a
contract deliverable item on military contracts
• 1962 Roger Lockwood held organizational
meetings in the Los Angeles area of what would
become the System Safety Society a professional
organization incorporated as an international, nonprofit organization
• 1964 The University of Southern California
developed a Master’s degree program to support
industry demands System Safety specialties
Acquisition Standards
• BSD Exhibit 62-41 was broadened in September
1963 as MIL-S-38130
• 1969 it became the model for MIL-STD-882
• MIL-STD 882 D is the latest version
• A standard updated over the years and existing
today
System Safety Management