System Development Life Cycle
“The Systems Development Life Cycle (SDLC) in systems engineering, information systems and software engineering, is the process of creating or altering systems and the models and the methodologies that people use to develop these systems. The concept generally refers to computer or information systems.
SDLC also is the entire process of formal, logical steps taken to develop a software product. Within the broader context of Application Lifecycle Management (ALM), the SDLC is basically the part of process in which coding/programming is applied to the problem being solved by the existing or planned application.
So basically Systems Development Life Cycle is used to analyze a business problem and transform it into an IT solution.
This article will be demonstrating the “systems development life cycle” the history, the phases which are: planning, analysis, design , coding, testing, and finally maintenance. The use of computers has exploded. Nowhere is this more evident than in the workplace. Computers run even manufacturing facilities. Can you just decide to throw some software program into a multi-million dollar manufacturing facility or financial institution and hope it works without breaking down? No one would want to take the chance. Do our computers have enough memory? Will it interfere with other programs? Does it really do what it is supposed to do? For that questions SDLC was developed.
Systems Development Life Cycle (SDLC) is a process used by a systems analyst to develop an information system, including requirements, validation, training, and user (stakeholder) ownership. Any SDLC should result in a high quality system that meets or exceeds customer expectations, reaches completion within time and cost estimates, works effectively and efficiently in the current and planned Information Technology infrastructure, and is inexpensive to maintain and cost-effective to enhance.
In project management a project can be defined both with a project life cycle (PLC) and an SDLC, during which slightly different activities occur. According to Taylor (2004) “the project life cycle encompasses all the activities of the project, while the systems development life cycle focuses on realizing the product requirements”.
The systems development life cycle (SDLC) is a type of methodology used to describe the process for building information systems, intended to develop information systems in a very deliberate, structured and methodical way, reiterating each stage of the life cycle. The systems development life cycle, according to Elliott & Strachan & Radford (2004), “originated in the 1960s to develop large scale functional business systems in an age of large scale business conglomerates. Information systems activities revolved around heavy data processing and number crunching routines”.
Several systems development frameworks have been partly based on SDLC, such as the Structured Systems Analysis and Design Method (SSADM) produced for the UK government Office of Government Commerce in the 1980s. Ever since, according to Elliott (2004), “the traditional life cycle approaches to systems development have been increasingly replaced with alternative approaches and frameworks, which attempted to overcome some of the inherent deficiencies of the traditional SDLC”.
Systems development phases
The systems development life cycle is divided to important phases that are essential for developers such as planning, analysis, design, and implementation. There are several models of SDLC exist, the oldest is the waterfall model: a sequence of stages in which the output of each stage becomes the input for the next. He number of steps seems to vary between four and seven and there is no correct model for SDLC because it depends on each project you plan to develop.
The feasibility study is sometimes used to present the project to upper management to get the approval and to have funding. Projects are evaluated in three main areas of feasibility: economical, organizational and technical.
The main objective of systems analysis is to determine where the problems in an attempt to help fix the system.
In systems, design functions and operations are described in detail, including screen layouts, business rules, process diagrams and other documentation. The output of this stage will describe the new systems as a collection of models or subsystems.
4. Build or coding
Modular and subsystem programming code will be accomplished during this stage. Unit testing and module testing are done in this stage by the developers. This stage is intermingled with the next in that individual modules will need testing before integration to the main project.
The code must be tested at various levels in software testing. Unit, system and user acceptance testings are often performed.
There are many types of testing such as: Data testing, integration testing, user acceptance testing, performance testing and more.
6. Operations and maintenance
The deployment of the system includes changes and enhancements before the sunset of the system. Maintaining the system is an important aspect of SDLC. As key personnel change positions in the organization, new changes will be implemented, which will require system updates.
And to give some examples about projects or systems that were developed using SDLC methodology, I would mention the telecom online payment systems, banking online services, M-Net mobile payment services and many more.
Strengths & Weaknesses
- It gives full definition to Systems Development Life Cycle.
- It provided the descriptions for each of the SDLC phases.
- It gave a brief history about the SDLC models.
- The illustrations weren’t helpful.
- It does not give examples on systems were developed by SDLC.
This article is basically about Systems Development Life Cycle (SDLC) what it is and about the phases such as: planning and how it is important to set the goals of the project, analysis and fixing problems, design creating modules, coding building according to the layouts, testing the systems, and finally maintenance. Also about the history of SDLC the basic model that was the waterfall and gave some examples of project that had been made using the systems development life cycle.
 SELECTING A DEVELOPMENT APPROACH. Retrieved 27 October 2008
 Software development life cycle (sdlc) / system development . http://www.mks.com
 “Systems Development Life Cycle”. In: Foldoc (2000-12-24)
 James Taylor (2004). Managing Information Technology Projects. p.39.