A system has a lifecycle consisting of many cycles from initial development, through deployment, operations, maintenance, legacy, and finally to discontinuation. The four fundamental phases of analysis, design, implementation, and testing can be applied to many different cycles and are not just limited to the development cycle as done in details in this thesis. See Figure A.1 on page for a visual representation of the software engineering lifecycle.
The analysis phase establishes the goals. The design phase establishes the plan to accomplish the goals. The implementation phase builds the system, while the testing phase assures quality.
A brief sketch follows on the decomposition of other lifecycles into the phases of analysis, design, implementation, and testing.