Systems Engineering

2.1 Life Cycle Example

The names, and the task contents, of a given project's stages can vary according to the needs of the project. However, a somewhat standard linear flow is often used in aerospace engineering, including space-related projects. The stages and typical major tasks include:

Conceptual Design

• Identifying the need - what is it you want the system to do? This is embodied in goals and requirements.
• Establish selection criteria - how do you decide one design is better than another?
• Establish a system concept - this includes the main functions, operation, and maintenance of the system.
• Feasibility analysis - can the need be met at acceptable cost, schedule, and other parameters.

Preliminary Design

• Functional analysis - identify and break down the complex system into smaller functions and their relationships, including alternate arrangements
• Design Allocation - subdivide and assign requirements to lower tier functions
• Formulate alternatives - develop alternate solutions - what are the range of possible options?
• System Modeling - develop mathematical models of the system so variations can be assessed.
• Optimization and selection - making each option as good as it can be, then compare options and choose the best.
• Synthesis and definition - combining the selected options into a total design, and recording the configuration and requirements details

Detail Design

• Design - Once broken down to a low enough level, individual elements are assigned to engineering specialties or design teams to complete. Design includes physical hardware components and facilities, as well as software, operating procedures, training, and other non-physical elements.
• Integration - Design elements are combined into larger functional units that work together, up to the system as a whole.
• Engineering Models and Prototypes - Physical partial models and complete prototypes built to validate the design.

Fabrication and Assembly

• Production of components - For physical items, the step where you make the parts.
• Assembly - Putting parts together into complete elements.

Test and Verification

• Element and System Test - At each assembly level, testing that the assembly functions, then moving up to larger assemblies to the final product.
• Verification - Proving the system meets the stated design requirements, by a combination of test, demonstration, inspection, and analyses.

Installation and Deployment

After production, the system elements may need delivery, installation, and activation at the location they will be used.

Operation and Maintenance

• Operation - Using the system for the purpose it was designed, in the intended environment.
• Support - which includes operator training, performance monitoring, and logistic support.
• Maintenance - includes planned maintenance and unplanned repair, and in-place upgrades.

Decommissioning

When the system has reached the end of its useful life, the removal, recycling, and disposal of system elements, and return of former sites to their original conditions.