To produce high-quality software on time, development teams have to follow highly structured testing and processes to increase efficiency and reduce the chance for bugs to occur. These processes are called Software Development Life Cycles, and many such methodologies exist. Show
Here, we’ll focus on what SDLCs are, the stages that fall under it, and why they matter. We also look at specific SDLC methodologies in detail. What is the Software Development Lifecycle?The Software Development Life Cycle (SDLC) is a systematic, multistep, iterative process for building and delivering software applications. Development teams rely on a system development life cycle to create reliable software with as few issues as possible. Phases of the Software Development Life CycleSDLC processes generally number at 6 distinct stages: planning, analysis, designing, development and testing, implementation, and maintenance. Each of them is briefly explained below. 1. PlanningThe very first phase of the SDLC starts with requirement gathering. This is known as the planning stage. It is the most important phase of the entire SDLC from the perspective of project managers and stakeholders. The planning stage answers such questions as:
2. AnalysisOnce all the requirements are known, it’s time to analyze them for feasibility and validity. The team decides whether it will be possible to add the requirements to the software. After that, a Requirement Specification document is designed. This serves as the guide for carrying out the next phase of the SDLC. 3. DesigningThis stage includes the designing of requirements specified in the very first phase of the SDLC. In addition to assisting in specifying hardware and system requirements, that stage also helps define the overall software architecture. The system design specifications prepared in the designing phase serve as the input for the next i.e. fourth stage of the SDLC. During the designing phase, testers are required to form an apt testing strategy. It contains what needs to be tested, and how it needs to be tested. 4. Development & TestingSome development teams consider development and testing to fall under a single-phase, others prefer to break it into two sub-phases. Irrespective of the choice a development team makes, the whole process remains the same. It’s all a matter of preference. Once the system design documentation is complete, the whole task is divided into modules or units. After that, the actual coding begins. Because this phase includes coding, it is the most important phase of the SDLC for the developer team. Moreover, this is the longest phase of the entire software development lifecycle. Once the code is fully developed, testing is carried out against the requirements. Testing includes functional testing, such as acceptance testing, integration testing, system testing, and unit testing, as well as non-functional testing. 5. ImplementationAlso known as the deployment phase, the implementation phase occurs right after the successful testing of the software product. It is focused on delivering the software to the end-user or installing it onto the customer’s system(s). The first thing that takes place once the product is delivered to the customer is beta testing. All bugs and enhancements are then reported to the developer team working on the project. Once the changes are complete, the final deployment takes place. 6. MaintenanceFinally, there’s the maintenance phase, which occurs over time after the product has been released. This phase deals with dealing with problems experienced by the customers/end-users while using the software. Advantages and Disadvantages of SDLCs
What is the best SDLC methodology?There is no straight answer to this question, as the software life cycle model you choose will depend on the size and scope of the software you are building, on top of other factors. The best SDLC methodology will always come down to the requirements and project context. There are also alternatives to the types of SDLC methodologies detailed further below. The most popular one is the RAD or Rapid Application Development. RAD offers implementation of CASE tools, joint application development, and prototyping. The advantages of RAD are active user involvement, a faster approach, and reduced development cost. Is Waterfall a Methodology?Yes, the waterfall is an SDLC methodology, and one of the oldest ones. The waterfall model is a linear methodology where every step must be completed before moving on to the next. All requirements and design choices are discussed first, and then deadlines are set for each stage’s completion. Learn Software Development Lifecycle Popular SDLC MethodologiesThere are several types of Software Development Life Cycle models. Each one has its own set of advantages and disadvantages. Though the approach might differ between models, each methodology has the goal of enabling the development team to deliver high-quality software in a cost-effective and quick manner. The following are 7 of the most popular SDLC methodologies. 1. Agile Software Development Life CycleThough the Agile model has existed for about two decades now, it has only gained traction within the past 5 - 10 years. The Agile methodology is so popular that some organizations are even using it for non-software-related projects. Agile is based on an incremental and iterative approach. Fast failure is a notable aspect of it, and Agile features ongoing release cycles. Each of these features small changes over the previous release, with the product tested with each iteration. A Scrum is a form of implementation of the Agile methodology that helps development teams structure complex project requirements. To complete assigned tasks, Scrum teams work in sprints, which is a period that lasts between 2 to 4 weeks. Daily Scrum meetings are organized to help the complete team monitor progress made up until that point. The one in charge of the Scrum team is known as the ScrumMaster. As usual, it’s their responsibility to keep the team on track for meeting the goal. Agile Pros:
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2. DevOps Software Development Life CycleThe DevOps methodology emerged from two trends. First, the application of Agile and Lean models to the operations team. Second, the general shift in business to seeing the value of cooperation between the operations and development staff at all the stages of the SDLC process. DevOps is a contraction for developers and operations. Following a DevOps methodology, the developer and operations teams work in tandem to accelerate and innovate the deployment and generation of highly-reliable software products. Important highlights of the DevOps model are continuous feedback, discipline, process improvement, and automation of as many manual development processes as possible. Updates made to the software under development are brief but at a higher frequency. DevOps Pros:
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3. Iterative Software Development Life CycleInstead of beginning with complete knowledge of requirements, project development teams following the iterative methodology implement a set of software requirements. Subsequently, they test, evaluate, and identify further requirements. Each phase or iteration in this model produces a newer, better version of the software under development. A rinse and repeat approach is followed until the final software comes into shape. A popular example of the Iterative model is the Rational Unified Process, a.k.a. RUP, developed by IBM’s Rational Software division. Pros:
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4. Lean Software Development Life CycleThe Lean methodology takes inspiration from lean manufacturing practices and principles. It follows a set of seven principles, which are:
Project teams working on the Lean model aim at finding opportunities to cut waste at every step of the SDLC process. Typically, this includes skipping unimportant meetings and reducing documentation. In actuality, the Lean methodology is very much similar to the Agile methodology with some noteworthy differences. The most important distinction between the two SDLC methodologies lies in terms of prioritizing customer satisfaction. The Agile model makes customer satisfaction a priority from the very beginning. Consequently, the project teams involved respond instantly to stakeholder feedback throughout the SDLC procedure. On the other hand, Lean methodology gives the topmost priority to the elimination of waste. This is done in order to create more overall value for the clients. Pros:
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5. Spiral Software Development Life CycleThe Spiral methodology is considered one of the most flexible SDLC models. Typically adopted for full-blown projects, the Spiral model lets development teams build a highly customized product. Spiral methodology passes through four phases repeatedly until the project is completed. This allows for following multiple rounds of product refinement. These four phases are planning, risk analysis, engineering, and evaluation. Each iteration of the Spiral methodology begins with predicting potential risks and the best way to avoid or mitigate them. Pros:
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6. V Software Development Life CycleV Model stands for Verification and Validation Model. Though inspired by the Waterfall model, where the testing is done at the end of the project, it differs in that it introduces testing at every stage of development. Similar to the Waterfall model, each next stage of the V model begins only when the previous one has been completed. Pros:
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7. Waterfall Software Development Life CycleLooking at this question asked on StackExchange, you will know that several experts believe that the Waterfall model was never meant to be a real, working SDLC methodology for developing software. Nonetheless, there are those taking the other side of the argument. The waterfall model is one of the oldest surviving SDLC methodologies, and any discussion about SDLC methodologies is incomplete without it. Though mostly usurped by the Agile model, the Waterfall model follows a straightforward approach, which is a desirable quality for many software development teams. Following the Waterfall methodology, a project development team needs to complete each phase step by step. There is no going backward with this model. Each successive phase of the SDLC process relies on the information gained from the preceding one. Pros:
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ConclusionThat sums up our list of the 7 most popular SDLC methodologies. Choosing the right SDLC methodology for developing any kind of software is very important, and it’ll come down to business requirements and project context. A wrong choice can put the entire process several steps back or even make it an irrecoverable project. What was your best or worst, or both kinds of software development experience? Share it with the community through the comment window below. People are also reading: |