Sdlc

Managing Information Technology Projects 를 저술 한 James Taylor 는. In systems engineering, information systems and software engineering, the software development life cycle (SDLC), also referred to as the application development life-cycle, is a process for planning, creating, testing, and deploying an information system. SDLC Defined: SDLC stands for software development lifecycle. A software development lifecycle is essentially a series of steps, or phases, that provide a framework for developing software and managing it through its entire lifecycle. The software development life cycle (SDLC) is a process by which software is developed and deployed. It’s a process that encompasses every phase of software creation, from conception to maintenance after the software is released. There are a variety of SDLC methodologies, including waterfall, agile and others. Teams select a specific. Requirement Analysis. The initial stage of the SDLC involves stakeholders from tech, business,.

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Software Development Life Cycle (SDLC) is a process used by the software industry to design, develop and test high quality softwares. The SDLC aims to produce a high-quality software that meets or exceeds customer expectations, reaches completion within times and cost estimates.

  • SDLC is the acronym of Software Development Life Cycle.

  • It is also called as Software Development Process.

  • SDLC is a framework defining tasks performed at each step in the software development process.

  • ISO/IEC 12207 is an international standard for software life-cycle processes. It aims to be the standard that defines all the tasks required for developing and maintaining software.

What is SDLC?

SDLC is a process followed for a software project, within a software organization. It consists of a detailed plan describing how to develop, maintain, replace and alter or enhance specific software. The life cycle defines a methodology for improving the quality of software and the overall development process.

The following figure is a graphical representation of the various stages of a typical SDLC.

A typical Software Development Life Cycle consists of the following stages −

Stage 1: Planning and Requirement Analysis

Requirement analysis is the most important and fundamental stage in SDLC. It is performed by the senior members of the team with inputs from the customer, the sales department, market surveys and domain experts in the industry. This information is then used to plan the basic project approach and to conduct product feasibility study in the economical, operational and technical areas.

Planning for the quality assurance requirements and identification of the risks associated with the project is also done in the planning stage. The outcome of the technical feasibility study is to define the various technical approaches that can be followed to implement the project successfully with minimum risks.

Stage 2: Defining Requirements

Once the requirement analysis is done the next step is to clearly define and document the product requirements and get them approved from the customer or the market analysts. This is done through an SRS (Software Requirement Specification) document which consists of all the product requirements to be designed and developed during the project life cycle.

Stage 3: Designing the Product Architecture

SRS is the reference for product architects to come out with the best architecture for the product to be developed. Based on the requirements specified in SRS, usually more than one design approach for the product architecture is proposed and documented in a DDS - Design Document Specification.

This DDS is reviewed by all the important stakeholders and based on various parameters as risk assessment, product robustness, design modularity, budget and time constraints, the best design approach is selected for the product.

A design approach clearly defines all the architectural modules of the product along with its communication and data flow representation with the external and third party modules (if any). The internal design of all the modules of the proposed architecture should be clearly defined with the minutest of the details in DDS.

Stage 4: Building or Developing the Product

In this stage of SDLC the actual development starts and the product is built. The programming code is generated as per DDS during this stage. If the design is performed in a detailed and organized manner, code generation can be accomplished without much hassle.

Developers must follow the coding guidelines defined by their organization and programming tools like compilers, interpreters, debuggers, etc. are used to generate the code. Different high level programming languages such as C, C++, Pascal, Java and PHP are used for coding. The programming language is chosen with respect to the type of software being developed.

Stage 5: Testing the Product

This stage is usually a subset of all the stages as in the modern SDLC models, the testing activities are mostly involved in all the stages of SDLC. However, this stage refers to the testing only stage of the product where product defects are reported, tracked, fixed and retested, until the product reaches the quality standards defined in the SRS.

Stage 6: Deployment in the Market and Maintenance

Once the product is tested and ready to be deployed it is released formally in the appropriate market. Sometimes product deployment happens in stages as per the business strategy of that organization. The product may first be released in a limited segment and tested in the real business environment (UAT- User acceptance testing).

Then based on the feedback, the product may be released as it is or with suggested enhancements in the targeting market segment. After the product is released in the market, its maintenance is done for the existing customer base.

SDLC Models

There are various software development life cycle models defined and designed which are followed during the software development process. These models are also referred as Software Development Process Models'. Each process model follows a Series of steps unique to its type to ensure success in the process of software development.

Following are the most important and popular SDLC models followed in the industry −

  • Waterfall Model
  • Iterative Model
  • Spiral Model
  • V-Model
  • Big Bang Model

Other related methodologies are Agile Model, RAD Model, Rapid Application Development and Prototyping Models.

SDLC, or Software Development Life Cycle, is a set of steps used to create software applications. These steps divide the development process into tasks that can then be assigned, completed, and measured.

What is the Software Development Life Cycle?

Software Development Life Cycle is the application of standard business practices to building software applications. It’s typically divided into six to eight steps: Planning, Requirements, Design, Build, Document, Test, Deploy, Maintain. Some project managers will combine, split, or omit steps, depending on the project’s scope. These are the core components recommended for all software development projects.

SDLC is a way to measure and improve the development process. It allows a fine-grain analysis of each step of the process. This, in turn, helps companies maximize efficiency at each stage. As computing power increases, it places a higher demand on software and developers. Companies must reduce costs, deliver software faster, and meet or exceed their customers’ needs. SDLC helps achieve these goals by identifying inefficiencies and higher costs and fixing them to run smoothly.

How the Software Development Life Cycle Works

The Software Development Life Cycle simply outlines each task required to put together a software application. This helps to reduce waste and increase the efficiency of the development process. Monitoring also ensures the project stays on track, and continues to be a feasible investment for the company.

Many companies will subdivide these steps into smaller units. Planning might be broken into technology research, marketing research, and a cost-benefit analysis. Other steps can merge with each other. The Testing phase can run concurrently with the Development phase, since developers need to fix errors that occur during testing.

The Seven Phases of the SDLC

1. Planning

In the Planning phase, project leaders evaluate the terms of the project. This includes calculating labor and material costs, creating a timetable with target goals, and creating the project’s teams and leadership structure.

Planning can also include feedback from stakeholders. Stakeholders are anyone who stands to benefit from the application. Try to get feedback from potential customers, developers, subject matter experts, and sales reps.

Planning should clearly define the scope and purpose of the application. It plots the course and provisions the team to effectively create the software. It also sets boundaries to help keep the project from expanding or shifting from its original purpose.

2. Define Requirements

Defining requirements is considered part of planning to determine what the application is supposed to do and its requirements. For example, a social media application would require the ability to connect with a friend. An inventory program might require a search feature.

Sdlc

Requirements also include defining the resources needed to build the project. For example, a team might develop software to control a custom manufacturing machine. The machine is a requirement in the process.

3. Design and Prototyping

The Design phase models the way a software application will work. Some aspects of the design include:

Architecture – Specifies programming language, industry practices, overall design, and use of any templates or boilerplate
User Interface – Defines the ways customers interact with the software, and how the software responds to input
Platforms – Defines the platforms on which the software will run, such as Apple, Android, Windows version, Linux, or even gaming consoles
Programming – Not just the programming language, but including methods of solving problems and performing tasks in the application
Communications – Defines the methods that the application can communicate with other assets, such as a central server or other instances of the application
Security – Defines the measures taken to secure the application, and may include SSL traffic encryption, password protection, and secure storage of user credentials

Prototyping can be a part of the Design phase. A prototype is like one of the early versions of software in the Iterative software development model. It demonstrates a basic idea of how the application looks and works. This “hands-on” design can be shown to stakeholders. Use feedback o improve the application. It’s less expensive to change the Prototype phase than to rewrite code to make a change in the Development phase.

4. Software development

This is the actual writing of the program. A small project might be written by a single developer, while a large project might be broken up and worked by several teams. Use an Access Control or Source Code Management application in this phase. These systems help developers track changes to the code. They also help ensure compatibility between different team projects and to make sure target goals are being met.

The coding process includes many other tasks. Many developers need to brush up on skills or work as a team. Finding and fixing errors and glitches is critical. Tasks often hold up the development process, such as waiting for test results or compiling code so an application can run. SDLC can anticipate these delays so that developers can be tasked with other duties.

Software developers appreciate instructions and explanations. Documentation can be a formal process, including wiring a user guide for the application. It can also be informal, like comments in the source code that explain why a developer used a certain procedure. Even companies that strive to create software that’s easy and intuitive benefit from the documentation.

Documentation can be a quick guided tour of the application’s basic features that display on the first launch. It can be video tutorials for complex tasks. Written documentation like user guides, troubleshooting guides, and FAQ’s help users solve problems or technical questions.

5. Testing

It’s critical to test an application before making it available to users. Much of the testing can be automated, like security testing. Other testing can only be done in a specific environment – consider creating a simulated production environment for complex deployments. Testing should ensure that each function works correctly. Different parts of the application should also be tested to work seamlessly together—performance test, to reduce any hangs or lags in processing. The testing phase helps reduce the number of bugs and glitches that users encounter. This leads to a higher user satisfaction and a better usage rate.

6. Deployment

In the deployment phase, the application is made available to users. Many companies prefer to automate the deployment phase. This can be as simple as a payment portal and download link on the company website. It could also be downloading an application on a smartphone.

Deployment can also be complex. Upgrading a company-wide database to a newly-developed application is one example. Because there are several other systems used by the database, integrating the upgrade can take more time and effort.

7. Operations and Maintenance

At this point, the development cycle is almost finished. The application is done and being used in the field. The Operation and Maintenance phase is still important, though. In this phase, users discover bugs that weren’t found during testing. These errors need to be resolved, which can spawn new development cycles.

In addition to bug fixes, models like Iterative development plan additional features in future releases. For each new release, a new Development Cycle can be launched.

SDLC Models & Methodologies Explained

Waterfall

Software Development Life Cycle Definition

The Waterfall SDLC model is the classic method of development. As each phase completes, the project spills over into the next step. This is a tried-and-tested model, and it works. One advantage of the Waterfall model is each phase can be evaluated for continuity and feasibility before moving on. It’s limited in speed, however, since one phase must finish before another can begin.

Agile

Sdlc Phases

The AGILE model was designed by developers to put customer needs first. This method focuses strongly on user experience and input. This solves much of the problems of older applications that were arcane and cumbersome to use. Plus, it makes the software highly responsive to customer feedback. Agile seeks to release software cycles quickly, to respond to a changing market. This requires a strong team with excellent communication. It can also lead to a project going off-track by relying too heavily on customer feedback.

Iterative

In the Iterative development model, developers create an initial basic version of the software quickly. Then they review and improve on the application in small steps (or iterations). This approach is most often used in very large applications. It can get an application up and functional quickly to meet a business need. However, this process can exceed its scope quickly and risks using unplanned resources.

DevOps

The DevOps security model incorporates operations – the people who use the software – into the development cycle. Like Agile, this seeks to improve the usability and relevance of applications. One significant advantage of this model is the feedback from actual software users on the design and implementation steps. One drawback is that it requires active collaboration and communication. Those additional costs can be offset by automating parts of the development process. Read our detailed comparison of devops vs. agile.

Other models

Many other SDLC models are essentially a variant of these core processes. Organizations use LEAN manufacturing processes for software development. V-shaped development is a type of Waterfall that implements testing, verification, and validation. Spiral development may pick and choose models for each step in the development process.

Best Practices Of Software Development

In addition to the models and stages of software development, there are a few other helpful practices. These can be applied to part or all of the development cycle.

Source Control

Source Control is a security plan to secure your working code. Implement Source Control by keeping the code in a single location, with secure and logged access. This could be a physical location where files are stored and accessed in a single room in the building. It could also be a virtual space where users can log in with an encrypted connection to a cloud-based development environment.

Source Control applications include a change management system to track work done by individuals or teams. As with any storage, use a backup system to record development progress in case of a disaster.

Continuous Integration

Continuous Integration evolved out of a case of what not to do. CI works to make sure each component is compatible through the whole development cycle. Before CI, different teams would build their own projects independently. This created significant challenges at the end when developers stitched the application together. Continuous Integration ensures all teams use similar programming languages and libraries, and helps prevent conflicts and duplicated work.

SDLC Management Systems

Sdlc Implementation Phase

A software development cycle management system works to control and manage each step of the development cycle. Management Systems add transparency to each phase and the project as a whole. They also add analytics, bug-tracking, and work management systems. These metrics or KPI’s can be used to improve parts of the cycle that aren’t running efficiently.

Conclusion: The Process for Software Development

Sdlc Life Cycle

SDLC shows you what’s happening, and exactly where your development process can improve.

Like many business processes, SDLC aims to analyze and improve the process of creating software. It creates a scalable view of the project, from day-to-day coding to managing production dates.

Sdlc Process

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