scope:

This Handbook is both a reference document and management tool for aiding managers and engineers at all levels in any Government or industrial organization. This Handbook describes how to develop and implement an effective SSS process. This process minimizes the likelihood or severity of system hazards caused by poorly specified, designed, developed, or operated software in safety-significant applications. Furthermore, technology refresh, operational upgrades, and operational risk during sustainment must be controlled or mitigated and are an integral part of the complete SSS process.

The primary responsibility for management of the SSS process lies with the system safety manager or engineer in both the developer's (supplier) and acquirer's (customer) organizations. However, every functional discipline has a vital role and must be involved in the SSS process. The SSS tasks, techniques, and processes outlined in this Handbook can be applied to any system that uses software in critical areas. The JSSSEH highlights the need for all contributing disciplines to understand and apply qualitative analysis techniques to ensure the safety of hardware systems controlled by software.

This Handbook, while extensive, is a guide and is not intended to supersede any Agency policy, standard, or guidance pertaining to system safety (e.g., Military Standard (MIL-STD)-882D) or software engineering and development (e.g., International Organization for Standardization (ISO) 12207). This Handbook is written to clarify the SSS requirements and tasks specified in Government and commercial standards and guidance documents. The Handbook provides the system safety manager and the software development manager with sufficient information to:

• Properly scope the SSS effort in the Statement of Work (SOW)

• Properly integrate the defined SSS tasks into the program's engineering and managements processes for each phase of the acquisition lifecycle

• Identify the data needed to monitor contractor compliance effectively with the contract system safety requirements

• Evaluate contractor performance throughout the development lifecycle.

This Handbook is not a tutorial for software engineering. However, the Handbook addresses some technical aspects of software design and function to assist with understanding software safety. This Handbook will provide each member of the SSS team with a basic understanding of sound systems and software safety practices, processes, and techniques. The JSSSEH will demonstrate the importance of each technical and managerial discipline working together to define software safety requirements (SSR) for the safety-significant software components of the system. The Handbook will also illustrate opportunities where the team can design additional safety features into the software to eliminate or control identified hazards.

Purpose

The purpose of the Handbook is to provide management and engineering guidelines to achieve a reasonable level of assurance that the software will execute within the system context with an acceptable level of safety risk.