This standard provides the set of Activities that constitute the Processes that are mandatory for the development and maintenance of software, whether stand-alone or part of a system. (Non-software Activities, such as hardware development and purchasing, are outside of the scope of this standard.) This standard also provides associated Input and Output Information. For convenience, Activities are listed and described under specific Processes. In practice, the Activities may be performed by persons whose organizational titles or job descriptions do not clearly convey that a Process is part of their job. The Process under which an Activity is listed in this standard may be transparent in practice. This standard does not prescribe a specific software life cycle model (SLCM). Each using organization must map the activities specified in the standard into its own software life cycle (SLC). If an organization has not yet defined an SLC, it will be necessary for them to select or define one before attempting to follow this standard. Further, this standard does not presume the use of any specific software development methodology nor the creation of specific documents. For software already developed, it is recommended that these requirements, or a subset there of, be applied. The existence of this standard should not be construed to prohibit the imposition of additional or more stringent requirements where the need exists, e.g., critical software. Compliance with this standard is defined in 1.5.1 .