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FAA System Safety Handbook, Chapter 2: System Safety Policy and Process
December 30, 2000
2- 1
Chapter 2: System Safety Policy and Process
2.1 FAA POLICIES ....................................................................................................................................2
2.2 THE FAA SAFETY RISK MANAGEMENT PROCESS....................................................................3
FAA System Safety Handbook, Chapter 2: System Safety Policy and Process
December 30, 2000
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2.0 System Safety Policy and Process
This section describes the System Safety policies and processes used within the FAA.
2.1 FAA policies
The primary policy governing safety risk management and system safety is formal in the FAA. Order 8040.4
and the Acquisition Management System (AMS). Note there are many other orders associated with safety.
When it is applicable to discuss them, the appropriate reference has been provided in the applicable section.
2.1.1 FAA Order 8040.4
This order sets requirements for the implementation of safety risk management within the FAA and
establishes the FAA Safety Risk Management Committee (SRMC).
Safety risk management
The order requires the FAA-wide implementation of safety risk management in a formalized, disciplined,
and documented manner for all high-consequence decisions. Each program office and Line of Business
(LOB) is required to establish and implement the policy contained within Order 8040.4 consistent with that
office¡¯s role in the FAA. While the methods and documentation requirements are left to the program office¡¯s
discretion, each is required to satisfy the following criteria:
Plan: The safety risk management process shall be predetermined, documented in a plan that must include the criteria
for acceptable risk.
Hazard identification: The hazard analyses and assessments required in the plan shall identify the safety risks
associated with the system or operations under evaluation.
Analysis: The risks shall be characterized in terms of severity of consequence and likelihood of occurrence in
accordance with the plan.
Comparative Safety Assessment: The Comparative Safety Assessment of the hazards examined shall be compared to
the acceptability criteria specified in the plan and the results provided in a manner and method easily adapted for
decision making.
Decision: The risk management decision shall include the safety Comparative Safety Assessment. Comparative Safety
Assessments may be used to compare and contrast options.
The order permits quantitative or qualitative assessments, but states a preference for quantitative. It requires
the assessments, to the maximum extent feasible, to be scientifically objective, unbiased, and inclusive of all
relevant data. Assumptions shall be avoided when feasible, but when unavoidable they shall be conservative
and the basis for the assumption shall be clearly identified. As a decision tool, the Comparative Safety
Assessment should be related to current risks and should compare the risks of various alternatives when
applicable.
In addition, the order requires each LOB or program office to plan the following for each high-consequence
decision:
Perform and provide a Comparative Safety Assessment that compares each alternative considered (including no action
or change, or baseline) for the purpose of ranking the alternatives for decision making.
Assess the costs and safety risk reduction or increase (or other benefits) associated with each alternative under final
consideration.
Safety Risk Management Committee
The SRMC is established by the Order to provide guidance to the program offices or LOBs, when requested,
on planning, organizing, and implementing Order 8040.4. The SRMC consists of technical experts in safety
risk management, with representation from each Associate/Assistant Administrator and the Offices of the
Chief Counsel, Civil Rights, Government and Industry Affairs, and Public Affairs.
FAA System Safety Handbook, Chapter 2: System Safety Policy and Process
December 30, 2000
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2.1.2 AMS Policies
The AMS policy contains the following paragraphs in 2.9.13:
System Safety Management shall be conducted and documented throughout the acquisition management lifecycle.
Critical safety issues identified during mission analysis are recorded in the Mission Need Statement; a system safety
assessment of candidate solutions to mission need is reported in the Investment Analysis Report; and Integrated Product
Teams provide for program-specific safety risk management planning in the Acquisition Strategy Paper.
Each line of business involved in acquisition management must institute a system safety management process that
includes at a minimum: hazard identification, hazard classification (severity of consequences and likelihood of
occurrence), measures to mitigate hazards or reduce risk to an acceptable level, verification that mitigation measures are
incorporated into product design and implementation, and assessment of residual risk. Status of System Safety shall be
presented at all Joint Resources Council (JRC) meetings. Detailed guidelines for system safety management are found
in the FAST.
2.2 The FAA Safety Risk Management Process
The FAA Safety Risk Management process is designed to evaluate safety risk throughout the National
Airspace System (NAS) life cycle. The primary focus of this process is to identify, evaluate, and control
safety risk in the NAS. Each LOB or program office has unique responsibilities in the NAS. As a reflection
of these responsibilities, the safety risk management program and the associated assessment tools/techniques
used by each office will be different from the other LOBs. The overall approach will remain the same: early
identification and control of those hazards that create the greatest risk within the NAS. The following
paragraphs summarize each office¡¯s approach to system safety risk management.
The safety risk management process operates as an integral part of the AMS under the oversight of the FAA
System Engineering Council. Figure 2-1 depicts the AMS Integrated Product Development System (IPDS)
process and the supporting system safety activities. The details of ¡°how¡± to perform each activity shown in
this diagram are discussed in later chapters. General guidance for AMS safety activities is contained in the
NAS System Safety Management Plan (SSMP).
System Safety Products in the AMS Life Cycle
Hazard Tracking &
Incident Investigation
Track Medium and
High Risks
Closed Loop/Risk
Acceptance
Capture & Analyze
Incidents
Identify high risk trends
for further detailed
investigation
Operating and Support
Hazard Analysis (O&SHA)
- Operating hazards (focus on
the human errors/factors details
- Support and Maintenance Hazards
System Hazard Analysis
(SHA)
- Looks at interfaces and
environment (operating
and ambient)
- NAS System Level
Subsystem Hazard Analysis (SSHA)
- NOT components (next level
below System
- Focus on faults and hazards
at SS level
- Detailed
- A few safety requirements
Comparative Safety
Assessment (CSA)/Preliminary
Hazard Analysis (PHA)
- Top - down, focus on known
system mission and approaches
and changes at NAS system level
- Preliminary in nature
- Core Safety Requirements
OSA
- - System Level
- - Preliminary (some
assumptions)
- Some Safety
Requirements
INTEGRATED PRODUCT
DEVELOPMENT SYSTEM
may fall out
Figure 2-1: Integrated Product Development System
The prime goal of the AMS system safety program is the early identification and continuous control of
hazards in the NAS design. The NAS is composed of the elements shown in Figure 2-2.
The outputs of the AMS system safety process are used by FAA management to make decisions based on
safety risk. These outputs are:
FAA System Safety Handbook, Chapter 2: System Safety Policy and Process
December 30, 2000
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Operational Safety Assessment (OSA)
Operational Safety Requirements (OSR)
Comparative Safety Assessments (CSA)
Preliminary Hazard Analyses (PHA)
Subsystem Hazard Analyses (SSHA)
System Hazard Analyses (SHA)
Operation and Support Hazard Analyses (O&SHA)
Hazard Tracking and Risk Resolution (HTR)
Other appropriate hazard analyses. (See Chapters 8 & 9)
Figure 2-2: Elements of the National Airspace System
2.2.1 Integrated Product Development System and Safety Risk Management Process
Figure 2-1 depicts the integrated product development system process and the supporting system safety
activities. The integrated product development system is broken down into a number of life cycle
milestones which include: Mission Analysis, Investment Analysis, Solution Implementation, In Service
Management, and Service Life Extension. As noted in Figure 2-1, system safety activities will vary
depending on the phase of the life cycle. The OSA is to be conducted during mission analysis, prior to the
mission need decision at JRC-1. During investment analysis, initial system safety analysis is further refined
into Comparative Safety Assessment and a Preliminary Hazard Analysis (as needed). After the investment
analysis, more formal system safety activities are initiated by the product teams for that program and in
FAA System Safety Handbook, Chapter 2: System Safety Policy and Process
December 30, 2000
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accordance with the NAS SSMP. During solution implementation, a formal system safety program plan is to
be implemented. System safety activities should include system and sub-system hazard analysis. Prior to the
in-service decision, operating and support hazard analysis is conducted to evaluate the risks during in-service
management, and service life extension.
Operating and Support Hazard analyses can also be conducted for existing facilities, systems, subsystems,
and equipment. Hazard tracking and risk resolution is initiated as soon as hazards and their associated risks
have been identified. This effort is continued until the risk controls are successfully validated and verified.
Accident and Incident investigation, as well as data collection and analysis are conducted throughout the life
cycle, to identify other hazards or risks that affect the system. The specific details within this safety analysis
process are further discussed in Chapter 4.
2.2.2 OSA and Comparative Safety Assessment (CSA)
The OSA and Comparative Safety Assessments are activities that occur prior to the establishment of baseline
requirements. The OSA provides the system designers and management with a set of safety goals for design.
It provides an environment description and a Preliminary Hazard List (PHL) for a given proposal or design
change. The OSA assesses the potential severity of the hazards listed in the PHL. These severity codes are
then mapped to a preset level of probabilities, which establishes the target safety level for controlling the
hazard. For instance, a catastrophic hazard would be mapped to a probability requirement that is more
stringent than a minor hazard. This process establishes the safety target level for controlling the hazard.
This target level, or goal assists in the establishment of safety requirements for the system design.
The Comparative Safety Assessment (CSA) is an analysis type that provides management with a listing of all
the hazards associated with a design change, along with a Comparative Safety Assessment for each
alternative considered. It is used to rank the options for decision-making purposes. The CSA for a given
proposal or design change uses the PHL developed for the OSA. The OSA process is depicted below in
Figure 2-3.
System
Description OED
Functions
PHL
Hazard
Severity
Analysis
OSA
OHA
ASOR
Safety
Objectives
SEC
JRC
Legend:
OED
PHL
ASOR
OHA
SEC
JRC
CONOPS
Operational Environment Protection
Preliminary Hazard List
Allocation of Safety Objectives
And Requirements
Operational Hazard Agreement
System Engineering Council
Joint Resources Council
CONOPS Concept of Operations
Figure 2-3: Operational Safety Assessment Process
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December 30, 2000
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2.2.3 Hazard Tracking and Risk Resolution
The purpose of hazard tracking and risk resolution is to ensure a closed loop process of identifying and
controlling risks. A key part of this process, management risk acceptance, ensures that the management
activity responsible for system development and fielding is aware of the hazards and makes a considered
decision concerning the implementation of hazard controls. This process is shown in Figure 2-4.
Safety Action Record (SAR)
The SAR is used for tracking hazard records and contains the following:
Reference Number - This is a specific number assigned to a SAR.
Date - The date in which the SAR has been initiated.
Status - The status of the SAR is indicated as open, monitor, or closed.
Title - A specific appropriate short title of the SAR is indicated.
Description - The description defines the specific hazardous event under study and its worst case outcome.
(The system safety related concern.)
Causes/Contributors - The contributory events singly or in combination that can create the event under
study. Specific failures, malfunctions, anomalies, errors are indicated.
Risk (Severity and Likelihood) - The risk associated with the event is indicated. Initial risk (the risk prior to
mitigation) is indicated. The residual risk (the worst case risks after the controls are implemented) is also
indicated.
Suggested/Possible Mitigations/Controls - The design and/or administrative controls, precautions, and
recommendations, to reduce risk are indicated. An objective is to design out the risks.
Evaluation - The appropriate activities and entities involved in the evaluation of the specific event are
indicated.
Implemented Mitigations/ Controls - The design and/or administrative controls, precautions, and
recommendations that have been verified within the design are indicated.
Verification and Validation - The verification and validation to assure that system safety is adequately
demonstrated are indicated. Risk controls (mitigation) must be formally verified as being implemented.
Safety verification is accomplished by the following methods: inspection, analysis, demonstration and test.
Validation is the determination as to the adequacy of the control.
Narrative History - Provide a chronological living history of all of the actions taken relative to the SAR.
References - Appropriate references associated with the specific SAR are indicated, Analysis, Configuration
Items, Software Units, Procedures, Tests, and Documents.
Originator(s) - The person(s) originating the SAR are listed.
Concurrence - Appropriate concurrence is required to status a SAR as closed (or monitor). IPT/ Program
Management concurrence is required for residual risk acceptance. Other concurrence rationale is also
documented, such as IPT (or FAA entity) concurrence.
2.2.4 Other Specific Safety Risk Management Processes
There are a number of other safety risk management processes discussed within the handbook involving
commercial space and facility system safety. These processes are discussed within their specific chapters.
This handbook does not discuss specific federal requirements associated with aircraft and ground
certification processes. Consult the appropriate Federal Aviation Regulations for certification related
processes.
FAA System Safety Handbook, Chapter 2: System Safety Policy and Process
December 30, 2000
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Adequate
Controls?
PHA
SSHA
SHA
O&SHA
Incidents
High Risk?
Hazard Analysis
Document
Hazard
Tracking
Report
SSWG
Evaluation
IPT
Evaluation
Active Hazard
Tracking
Report
Additional
Controls?
Signed Hazard
Tracking
Report
JRC/SEC
Risk
Acceptance
Risk
Accepted?
Design or
Rqmt change
Hazard Analyses
merge
YES
NO
YES
YES
YES
NO
NO
NO
Figure 2-4: Hazard Tracking and Risk Resolution Process
2.2.5 FAA Corporate Comparative Safety Assessment Guidelines
FAA Report No. WP-59-FA7N1-97-2, Comparative Safety Assessment Guidelines for the Investment
Analysis Process, Update of July 1999, presents guidelines for conducting life-cycle Comparative Safety
Assessment as part of the FAA¡¯s Investment Analysis Process (IAP). Since the first publication of these
Guidelines in June, 1997, information security, human factors and safety issues have gained viability and
prominence as additional risks to be considered. Risk in this context relates to the ¡°probability that an
alternative under consideration in the IAP will fail to deliver the benefits projected for that alternative, either
in whole or in part, and the consequences of this failure.¡±