Systems Development Life Cycle (sdlc) Explained

Systems Development Life Cycle (SDLC) Explained

Defined simply at Dictionary.com, a Systems Development Life Cycle (SDLC) is:

Any logical process used by a systems analyst to develop an information system, including requirements, validation, training, and user ownership.

An SDLC should result in a high quality system that meets or exceeds customer expectations, within time and cost estimates, works effectively and efficiently in the current and planned Information Technology infrastructure, and is cheap to maintain and cost-effective to enhance.

While SDLC may be a specific process used in the IT world, its spirit can be found in any decision-making process in any arena. In most models of decision-making, there are four basic phases: Identification phase, Development of alternatives, Selection phase, and the Evaluation phase. SDLC incorporates five to six distinct phases, which utilizes the four previously mentioned phases. SDLC is a detailed model that describes the stages involved in an information system development project, from an initial feasibility study through maintenance of the completed application.

In every decision-making process, the players or participants can be as important as the process itself. In some business decisions, not every member of the organization will be consulted before a decision is reached. For example, a company trying to cut costs may decide to make changes without seeking every employee's opinion or approval. They may decide to change distributors for their office supplies to take advantage of lower prices.

However, in the System Development Life Cycle, all end-users affected should be part of the initial planning process. System analysts and programmers are vital to the behind-the-scenes development. Nickerson suggests that the end-users are just as vital, since they will help determine the success of the process. "An information system is designed to meet the needs of its users. To accomplish this goal, the users must explain their needs to the systems analysts. In addition, the users must determine whether the system that is developed meets their needs" (Nickerson 16).

SearchVB.com, a TechTarget site for VB professionals, points out that there are various SDLC methodologies. These methods have been developed to guide the processes involved; they include the waterfall model (which was the original SDLC method); rapid application development (RAD); joint application development (JAD); the fountain model; the spiral model; build and fix; and synchronize-and-stabilize. Frequently, several models are combined into some sort of hybrid methodology.

Despite which methodology, or hybrid is chosen, in general, SDLC follows the following six steps according to our Workshop #1 handout entitled, System Development life Cycle (SDLC):

1. Systems Investigation Phase: The existing system is evaluated. Deficiencies are identified. This can be done by interviewing users of the system and consulting with support personnel.

2. System Analysis Phase: The new system requirements are defined. In particular, the deficiencies in the existing system must be addressed with specific proposals for improvement.

3. System Design Phase: The proposed system is designed. Plans are laid out concerning the physical construction, hardware, operating systems, programming, communications, and security issues.

4. System Development Phase: The new system is developed. The new components and programs must be obtained and installed. Users of the system must be trained in its use, and all aspects of performance must be tested. If necessary, adjustments must be made at this stage.

5. System Implementation Phase: The system is put into use. This can be done in various ways. The new system can phased in, according to application or location, and the old system gradually replaced. In some cases, it may be more cost-effective to shut down the old system and implement the new system all at once.

6. System Maintenance Phase: Once the new system is up and running for a while, it should be exhaustively evaluated. Maintenance must be kept up rigorously at all times. Users of the system should be kept up-to-date concerning the latest modifications and procedures.

It is essential for all companies to have a thorough process like this established. SDLC helps companies determine when and whether or not an upgrade is needed in their information system. The speed at which new technology enters the market place is phenomenal. Our "modern world is undergoing a fundamental transformation" (Sehrt 45). "This dynamic process promises a fundamental change in all aspects of our lives, including knowledge dissemination, social interaction, business practices, political engagement, media, education, health, leisure and entertainment" (Sehrt 45). Companies need to have a foolproof method by which they can use to make decisions about new technology.

One current trend for 2004 is WiFi technology. Patrick Lo, Chairman and CEO of Netgear, suggests that:

"WiFi will become widespread worldwide in 2004. We expect homes to reach up to 20 percent penetration