An Application Lifecycle in 8 Phases (Continued)

Testing and Quality Assurance
The fourth and fifth phases involve application testing and quality assurance (also see the FTPOnline Special Report on Testing and Performance). These phases apply to both in-house development projects and commercial software products. The initial testing phase focuses on the initial developer or software packager. As developers begin to program new code, they first work on their own local system. As they progress through the development cycle, they migrate the code from their system to servers where it can be shared and integrated with other components created by their teammates.

Most organizations today use this testing and stabilization process, which includes five steps; two occur locally on the developer's workstation, and three take place on centralized servers:

• Unit Testing: Developing and testing single components on the local machine by individual developers. Developing and testing initial software packages locally by individual packagers.
• Functional Testing: Ensuring that the new components perform the functions they are designed for or ensuring that the custom configuration will offer all the required functionality. Once again, this is usually on a local system. This completes the testing phase of the lifecycle.
• Integrated Testing: The new components are moved to a central server to integrate them with components created by other programmers. This test checks whether all the components can work together as expected. In an ideal situation, these components are also integrated with every other component found in the production network.
• Acceptance Testing: Users or clients are brought in to review the operation of the new program. They will accept the program if it performs the functions they requested in the first place.
• Pre-Production Testing: The code or package is moved to a final environment to test its performance in a production-like system. If it passes this final test, it will be deployed to the production environment. This completes the stabilizing phase.

During both of these phases, it is critical to focus on product quality and complete documentation. As you can see, developers and packagers begin by working on their own local machine, and move to central environments as the program/package evolves. This is the scope of the traditional application lifecycle.