System development life cycle

Traditional methodology for developing, maintaining, and replacing information systems

 Phases in SDLC:

1. Planning
2. Analysis
3. Design
4. Implementation
5. Maintenance

 Computer systems have become more complex and often link multiple traditional systems potentially supplied by different software vendors. To manage this level of complexity, a number of system development life cycle (SDLC) models have been created: "waterfall," "fountain," "spiral," "build and fix," "rapid prototyping," "incremental," and "synchronize and stabilize."

Initiation/planning
To generate a high-level view of the intended project and determine the goals of the project. The feasibility study is sometimes used to present the project to upper management in an attempt to gain funding. Projects are typically evaluated in three areas of feasibility: economical, operational, and technical.

Requirements gathering and analysis
The goal of systems analysis is to determine where the problem is in an attempt to fix the system. This step involves breaking down the system in different pieces and drawing diagrams to analyze the situation, analyzing project goals, breaking need to be created and attempting to engage users so that definite requirements can be defined.

Design
In systems design functions and operations are described in detail, including screen layouts, business rules, process diagrams, and tables of business rules, business process diagrams, pseudo code, and a complete entity-relationship diagram with a full data dictionary. The output of this stage will describe the new system as a collection of modules or subsystems.

Implementation
Its include build or coding and testing
Modular and subsystem programming code will be accomplished during this stage. Unit testing and module testing are done in this stage by the developers before integration to the main project.
Unit, system and user acceptance testing are often performed. This is a grey area as many different opinions exist as to what the stages of testing are and how much if any iteration occurs. Types of testing:
Unit testing, Module testing ,System testing ,Black box testing ,White box testing ,Regression testing ,User acceptance testing

Operations and maintenance
The deployment of the system includes changes and enhancements of the system. As key personnel change positions in the organization, new changes will be implemented, which will require system updates.