This standard describes an iterative process for managing and executing software maintenance activities. Use of this standard is no restricted by sized, complexity, critically, or application of the software product. this standard uses the process mode, depicted in table 2, to discuss and depict each phase of software maintenance, The criteria established apply to both the planning of maintenance for software while under development, as well as the planning and execution of software maintenance activities for existing software products. Ideally, maintenance, planning should begin during the stage of planning for software development (see annex clause A.,3 for guidance).