This International Standard specifies the Systems Security Engineering – Capability Maturity Model® (SSE-CMM®). The SSE-CMM® is a process reference model focused upon the requirements for implementing security in a system or series of related systems that are the information technology security (ITS) domain. Within the ITS domain, the SSE-CMM® is focused on the processes used to achieve ITS, most specifically on the maturity of those processes. There is no intent within the SSE-CMM® to dictate a specific process to be used by an organization, let alone a specific methodology. Rather the intent is that the organization making use of the SSE-CMM® should use its existing processes, be those processes based upon any other ITS guidance document. The scope encompasses: • the system security engineering activities for a secure product or a trusted system addressing the complete life cycle of concept definition, requirements analysis, design, development, integration, installation, operation, maintenance and de-commissioning; • requirements for product developers, secure systems developers and integrators, organizations that provide computer security services and computer security engineering; and • all types and sizes of security engineering organization, from commercial to government and the academe. While the SSE-CMM® is a distinct model to improve and assess security engineering capability, this does not imply that security engineering should be practised in isolation from other engineering disciplines. On the contrary, the SSE-CMM® promotes integration, taking the view that security is pervasive across all engineering disciplines (e.g., systems, software and hardware) and defining components of the model to address such concerns. The Common Feature “Coordinate Practices” recognizes the need to integrate security with all disciplines and groups involved on a project or within an organization. Similarly, the Process Area “Coordinate Security” defines the objectives and mechanisms to be used in coordinating the security engineering activities.