system lifecycle
life cycle of an engineered system which may include phases such as system conception, design and development, production and/or construction, distribution, operation, maintenance and support, retirement, phase-out and disposal
systems development life-cycle
process for planning, creating, testing, deploying, and maintaining an engineered system
Safety life cycle
series of phases from initiation and specifications of safety requirements, covering design and development of safety features in a safety-critical system, and ending in decommissioning of that system