Professional SQL Server™ 2005 Integration Services

18.1. Introduction to Software Development Life Cycles

Software Development Life Cycles (or SDLCs) are a systematic approach to each component of application development—from the initial idea to a functioning production application. A step (or phase) is a unit of related work in an SDLC. A methodology is a collection of SDLC steps in action, applied to a project. Artifacts are the recorded output from steps.

For example, the first step of an SDLC is Analysis. The methodology requires a requirements document as an Analysis artifact.

18.1.1. Software Development Life Cycles: A Brief History

Software Development Life Cycles have existed in some form or other since the first software applications were developed. The true beginning of what is now termed "software" is debatable. For your purposes, the topic is confined to binary operations based on Boolean algebra.

In 1854, mathematician George Boole published An Investigation of the Laws of Thought, on which are founded the Mathematical Theories of Logic and Probabilities. This work became the foundation of what is now called Boolean algebra. Some 80 years later, Claude Shannon applied Boole's theories to computing machines of Shannon's era. Shannon later went to work for Bell Labs.

Another Bell Labs employee, Dr. Walter Shewhart, was tasked with quality control. Perhaps the pinnacle of Dr. Shewhart's work is statistical process control (SPC). Most quality control and continuous improvement philosophies in practice today utilize SPC. ...