• Affected human elements (e.g., pilots, controllers, maintenance personnel, supervisors, etc.), and • Operational procedures related to or affected by the concept. Using the concept description and preliminary input from the FA, identify and list the required  functions (including those that are performed by the users). For example, the primary function  of a precision navigation system is to provide ATC and flight crews with vertical and horizontal  directional guidance to the desired landing area. If desired, these functions could be split into  vertical and horizontal guidance. Supporting functions would be those that provide the solution  with the ability to perform the primary function. A supporting function of the precision navigation  system would be transmission of the radio frequency energy for horizontal guidance. The PO  must determine how to group these functions and to what level of rigor to take the analysis.  Develop and document the OSED from the information obtained in the first three steps (i.e., the  steps outlined in  Section 5.1.1 through Section 5.1.3).  Once the solution has been bounded and described and the functions have been identified in  the OSED, an SRM panel must identify the associated hazards via an OHA. 6 In developing an  OHA, the panel must develop a PHL 7  using a systematic analysis of solution functions and  functional failures to identify hazards. Each hazard must be subsequently classified according  to its potential severity after considering causes and effects. The OHA uses the severity  identified for each hazard to identify safety objectives and safety requirements for the solution  that will result in an acceptable level of safety risk.  In general, as severity increases, the safety objectives and safety requirements must be  designed to achieve the lowest possible likelihood of occurrence. A safety objective or “goal” in  the context of the OHA is the desire to reduce the likelihood of an identified safety hazard. The  associated safety requirement (i.e., minimum level of acceptable performance) is the means of  attaining that objective. The OHA must establish safety objectives that ensure an inverse  relationship between the probability of a hazard leading to an incident or accident and the  severity of the hazard’s outcome. The safety objective should result in the lowest practicable  acceptable level of safety risk.  The OHA may be performed using either qualitative or quantitative methods. However, it is  preferable to use quantitative data to support the assessment. 8 Figure C.3 provides an  overview of the steps required to conduct an OHA. 5.2  OHA Development Process 5.1.4  Develop and Document the OSED  5.1.3  Determine and List Functions  6. The SMS Manual provides guidance on how to assemble SRM panels and facilitate the panel process. 7. The concept of the PHL is explained in the SMS Manual. 8. Various databases have been developed to support the SMS. Some of these are listed in the SMS Manual. C_SRMGSA_202003  Originally published March 2020  Uncontrolled copy when downloaded  C-9