System development life cycle (SDLC)

Basic Concept of SDLC – System Development Life Cycle

A successful Organizations use a standard set of steps, called a systems development methodology, to develop and support their information systems. Like many processes, the development of information systems often follows a life cycle.
For example, a commercial product, such as a

  • Nike sneaker or
  • a Honda car,

follows a life cycle:

  1. It is created,
  2. tested, and
  3. introduced to the market.
  4. Its sales increase,
  5. peak, and
  6. decline.
  7. Finally, the product is removed from the market and
  8. is replaced by something else.

The systems development life cycle (SDLC) is a common methodology for systems development in many organizations.
It marks the phases or steps of information systems development:

  • Someone has an idea for an information system and what it should do.
  • The organization that will use the system decides to devote the necessary resources to acquiring it.
  • A careful study is done of how the organization currently handles the work the system will support.
  • Professionals develop a strategy for designing the new system,
  • which is then either built or purchased.
  • Once complete, the system is installed in the organization, and
  • after proper training, the users begin to incorporate the new system into their daily work.

Every organization uses a slightly different life-cycle model to model these steps, with anywhere from three to almost twenty identifiable phases.

A successful System Development Life Cycle (SDLC) should result in an astounding system that meets client desires, achieves expectations within time and cost assessments, and works viably and productively in the current and planned Information Technology framework. 

System Development Life Cycle (SDLC) is an applied model which incorporates strategies and methods for creating or modifying systems throughout their life cycles. 

SDLC is utilized by examiners to build up a data system. SDLC incorporates the accompanying exercises −

  • requirements
  • design
  • implementation
  • testing
  • deployment
  • operations
  • maintenance

Basic Four phases of SDLC

The system development life cycle structure gives a grouping of exercises to system designers and engineers to take after. It comprises of an arrangement of steps or stages in which each period of the SDLC utilizes the aftereffects of the past one. 

The SDLC holds fast to critical stages that are basic for engineers, for example, planning, analysis, design, and implementation—and are clarified in the area beneath. This incorporates assessment of the presently utilized system, data gathering, feasibilty studies, and demand endorsement. Various SDLC models have been made, including waterfall, fountain, spiral, build and fix, rapid prototyping, incremental, synchronize, and stabilize. The oldest of these, and the best known, is the waterfall model, a succession of stages in which the yield of each stage turns into the contribution for the next. These stages can be described and partitioned up in various ways, including the following:

  1.  planning and selection,
  2.  analysis,
  3.  design, and
  4.  implementation and operation (see Figure 1).

System development life cycle (SDLC)

figure: 1


Feasibility Study or Planning 

  1. Characterize the issue and extent of existing system. 
  2. Diagram the new system and decide its goals. 
  3. Affirm venture feasibility and deliver the task Schedule. 
  4. Amid this stage, dangers, imperatives, combination and security of system are likewise considered. 
  5. A feasibility report for the whole venture is made toward the finish of this stage. 

Analysis and Specification 

  1. Assemble, examine, and approve the data. 
  2. Characterize the prerequisites and models for new system. 
  3. Assess the options and organize the prerequisites. 
  4. Analyze the data needs of end-client and upgrades the system objective. 
  5. A Software Requirement Specification (SRS) archive, which determines the product, equipment, useful, and organize prerequisites of the system is set up toward the finish of this stage. 

System Design 

  1. Incorporates the design of utilization, organize, databases, UIs, and system interfaces. 
  2. Change the SRS report into coherent structure, which contains definite and finish set of specifications that can be executed in a programming dialect. 
  3. Make a possibility, preparing, maintenance, and activity design. 
  4. Survey the proposed design. Guarantee that the last design must meet the prerequisites expressed in SRS record. 
  5. At long last, set up a design record which will be utilized amid next stages. 


  1. Execute the design into source code through coding. 
  2. Join every one of the modules together into preparing condition that recognizes mistakes and imperfections. 
  3. A test report which contains mistakes is set up through test arrange for that incorporates test related undertakings, for example, experiment age, testing criteria, and asset allotment for testing. 
  4. Incorporate the data system into its condition and introduce the new system. 


  1. Incorporate every one of the exercises, for example, telephone support or physical on location support for clients that is required once the system is introducing. 
  2. Execute the progressions that product may experience over some undefined time frame, or actualize any new necessities after the product is sent at the client area. 
  3. It additionally incorporates handling the leftover blunders and resolve any issues that may exist in the system even after the testing stage. 
  4. Maintenance and support might be required for a more extended time for vast systems and for a brief span for littler systems.

System development life cycle (SDLC)


Although any life cycle appears at first glance to be a sequentially ordered set of phases, it actually is not. The specific steps and their sequence are meant to be adapted as required for a project. For example,

  • in any given SDLC phase, the project can return to an earlier phase, if necessary.
  • Similarly, if a commercial product does not perform well just after its introduction, it may be temporarily removed from the market and improved before being reintroduced.
  • In the systems development life cycle, it is also possible to complete some activities in one phase in parallel with some activities of another phase.
  • Sometimes the life cycle is iterative; that is, phases are repeated as required until an acceptable system is found.
  • Some systems analysts consider the life cycle to be a spiral, in which we constantly cycle through the phases at different levels of detail, as illustrated in Figure 2.
  • The circular nature of the life-cycle diagram in Figure 2 illustrates how the end of the useful life of one system

System development life cycle (SDLC)

figure: 2

leads to the beginning of another project that will replace the existing system altogether. However conceived, the systems development life cycle used in an organization is an orderly set of activities conducted and planned for each development project. The skills required of a systems analyst apply to all lifecycle models

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Frequently Asked Questions

Ans: Change Agent: The analyst may be viewed as an agent of change. A candidate system is designed to introduce change and reorientation in how the user organization handles information or makes decisions. Then, it is important that the user accepts change. view more..
Ans: Systems Analyst Duties: Defines application problem by conferring with clients; evaluating procedures and processes. Develops solution by preparing and evaluating alternative workflow solutions. Controls solution by establishing specifications; coordinating production with programmers. Validates results by testing programs. view more..
Ans: The primary role of a systems analyst is to study the problems and needs ofan organization in order to determine how people, methods, and information technology can best be combined to bring about improvements in the organization. A systems analyst helps system users and other business managers define their requirements for new or enhanced information services. view more..
Ans: Systems development methodology: A standard process followed in an organization to conduct all the steps necessary to analyze,design, implement, and maintaininformation systems. | Systems development life cycle (SDLC): The series of steps used to mark the phases of development for an information system. view more..
Ans: Systems Planning and Selection : The first phase of the SDLC, in which an organization’s total information system needs are analyzed and arranged, and in which a potential information systems project is identified.Systems Analysis : Phase of the SDLC in which the current system is studied and alternative replacement systems are proposed. view more..
Ans: System documentation: Detailed information about a system’s design specifications, its internal workings, and its functionality. Internal documentation: System documentation that is part of the program source code or is generated at compile time. view more..
Ans: Management should not be lenient on part of documentation, management should never say like  “ as time running short , so just create the system and make the documentation later”. Phase should not be considered complete until documentation is done. Coding should not be considered done unless its has required comment lines. view more..
Ans: There are various techniques to gather data and facts of system. some of them re as follows : Record view and Background reading Interviews  Questionnaires Group communication Presentation Site visiting Observation view more..
Ans: Feasibility studies are almost always conducted where large sums are at stake. Also called feasibility analysis. A feasibility study is conducted in order to determine the success and minimize the risks related to the project. When it becomes certain that the specific project could be carried out profitably view more..
Ans: It is a final report of the feasibility study about the findings and conclusion of the study. it should be possible to review report and take decision on the project based on it view more..
Ans: System selection means selecting the various hardware, software, and services that are needed for implanting the system. Before the system selection can be done, it is necessary to know the capabilities of required proposed system view more..
Ans: Costs fall into two categories. There are cost associated with developing the systems and there are costs associated with a operating a system. view more..
Ans: Quantitative measure of degree to which a system, component or process possesses a given attribute For ex. No. of errors found per person hours expended Cost and Effort Estimation : Boehm’s COCOMO model, Putnam’s SLIM Model & Albrecht’s function model. view more..
Ans: There are three such classes: Process are collection of software related activities. Products are any artifacts, deliverables or documents that result from a process activity view more..
Ans: A direct measure is obtained by applying measurement rules directly to the phenomenon of interest.For example, by using the specified counting rules, a software program’s “Line of Code” can be measured directly. and sofware reliabity is .... view more..
Ans: What Is Information Systems Analysis and Design? Information systems analysis and design is a method used by companies ranging from IBM to PepsiCo to Sony to create and maintain information systems that perform basic business functions such as keeping track of customer names and addresses, processing orders, and paying employees. The main goal of systems analysis and design is to improve organizational systems, typically through applying software that can help employees accomplish key business tasks more easily and efficiently. As a systems analyst, you will be at the center of developing this software. view more..
Ans: concurrency of components, lack of a global clock and independent failures of components and the ability to work well when the load or the number of users increases – failure handling, concurrency of components, transparency and providing quality of service view more..
Ans: the wide range of applications in use today, from relatively localized systems (as found, for example, in a car or aircraft) to globalscale systems involving millions of nodes, from data-centric services to processorintensive tasks, from systems built from very small and relatively primitive sensors to those incorporating powerful computational elements, from embedded systems to ones that support a sophisticated interactive user experience, and so on. view more..

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