ISO IEC 15288 / INCOSE SEBoK v3.0 Life Cycle Stages

Life-cycle definition is an important aspect of any system. By defining a life-cycle we can establish a framework for meeting stakeholder needs in an orderly fashion.

This order comes from the presence of stages in the life-cycle, and decision-making at the end of each stage to determine the readiness to move on. Stakeholders are concerned with the business case, funding and capability of a system at each stage.

INCOSE SEBoK ver 3.0 defines seven life-cycle phases. Each of these phases are listed below. Phases 2 - 7 are the same as the six phases defined in ISO 15288.

Pre-concept Phase:
Inputs: New ideas
Process: Creative systems engineering and requirements definition
Outputs: Identified enabling technologies

Concept Phase:
Inputs: Studies, experiments, models
Process: Requirements identification (if not done in pre-concept), indepth feasibility studies, prototypes, risk evaluation, early validation
Outputs: System requirements, feasible design solution

Development Phase:
Input: System requirements
Process: Development, integration, verification and validation
Outputs: Developed, verified and validated system

Production Phase:
Input: Tested system
Process: Modifications, re-verification, cost reduction
Output: Manufactured product

Utilization Stage:
Input: Performance reports, change requests, operational work orders
Process: Operations, change management
Output: Operational product, upgrades

Support Stage:
Inputs: Modifications, change requests
Process: Change control, maintenance, cost reduction, support
Output: Sustainable service and supported mission

Retirement Stage:
Inputs: change requests, competing systems
Process: System migration, removal, disposal
Output: Disposed system