separately documented. These changes include preliminary requirements from interdependent  investments, new/modified air traffic control procedures, compliance with updates to the Code of  Federal Regulations, and lifecycle-integrated logistics support (e.g., maintenance, training). At  this stage, the initial Program Requirements Document (iPRD) defines the program’s needs and  requirements at a high level.  The Development Assurance Level (DAL) for each alternative (if applicable) is validated in the  CSA. ( Note : The DAL may differ among the investment alternatives assessed.) 5 The output of the CSA should be used as an input to other Safety Risk Management (SRM)  documents, particularly a Preliminary Hazard Analysis (PHA), 6  as the capability/solution  alternative pros and cons are debated after the IID.  The Safety Requirements Verification Table (SRVT) contains all of the safety requirements  identified, starting with the origin of the requirement, and should include the requirements  identified in the CSA. The final SRVT is not required until the System Safety Assessment  Report is prepared.  This section describes the CSA development process.  The following are examples of inputs to the CSA.  Investment analyses should bring at least three diverse, yet technically viable alternatives  forward for selection of a preferred solution alternative. Ideally, the reference case is not one of  these alternatives. Instead, it is a baseline against which the alternatives are compared. Consider the fact that the reference case is not always a “do-nothing” scenario, since many  legacy program activities may already be in place and may go through some default evolution  during the required implementation time of the alternative solutions. Therefore, potential safety  consequences stemming from letting an existing system continue without further investment and  without the targeted new capability must be fleshed out. This should address whether the  targeted new capability is an improvement or a deterioration to the existing system.  OSAs previously conducted for the Investment Analysis Readiness Decision may provide  relevant information concerning safety hazards, causes, solution states, effects, and severity  assessments to the CSA. Using these as inputs to the CSA, the likelihood of each  hazard/cause/effect must be determined and matched with severity ratings. Differences among  alternatives should begin to emerge, which could impact the combinations of cause/effect  severity and likelihood ratings associated with each hazard. Ratings that are identical across all  4.1.2  OSAs  4.1.1  Identified Alternatives  4.1  Initial Inputs  4  Procedures 3.3.3  Preparing Safety Risk Management Documents  3.3.4  Preparing/Revising the Safety Requirements Verification Table  3.3.2  Establishing the Development Assurance Level  5. The DAL for the eventually selected alternative is included in the iPRD and the initial  Implementation Strategy and Planning Document prior to the Final Investment Decision (FID) . 6. A PHA is best compiled after the alternatives are evaluated and a single alternative is selected as the best option. The PHA is conducted after the CSA and before the FID. D_SRMGSA_202003 Originally published March 2020  Uncontrolled copy when downloaded  D-3