What is SDLC? Understand 7 Stages of Software Development Life Cycle

Want to learn how the SDLC works?

You have landed on the right blog post. This blog post will help answer your questions regarding SDLC in software engineering.

As an experienced software development company, we know the importance of SDLC and how it allows developers to create custom software with proper structure and methodical way. This way, the overall development of your project goes smoothly and developers don’t need to face many issues and you get expected results against your invested money and efforts.

So, what does the software development life cycle mean?

Let’s understand.

What is SDLC?

SDLC is a process consisting of several distinct phases like plan, design, develop, test, and launch for delivering software. Developers use this process to create high-standard and bug-free custom software.

A software development life cycle is often termed SDLC. Using SDLC, developers are able to develop software applications according to clients’ needs and within described budget and timeline.

Now, as you got the idea of what is life cycle of software development. The next question arises, what are the 7 phases of SDLC? Let’s understand in detail. 

Phases of SDLC (Software Development Life-Cycle)

Let’s understand the 7 phases of SDLC in detail.

1. System Requirement Analysis and Planning

   The requirement phase is the first stage of SDLC where the BA team collects information about the software solution client wants to develop. The business stakeholders need to address the specifications for the end product, to define the system requirements in depth. It involves of a project charter which sets out stakeholder, focus group, and customer requirements. This comes under the planning phase. So, it becomes helpful to create a WBS (WorkBreak Down Structure) document.

   To be more precise, you can understand this planning phase in 3 simple steps.

   • Identify the requirements of business stakeholders, individuals and customers to cope with the software trends in the production environment.
   • Get the validation of identified project requirements.
   • Plan the software project based on validated requirements.

   In brief, the planning phase aims to evaluate the complexity of the issue and the software solution to it. During this phase, you need to decide on the different software development tools, environments in software development, software development framework.

2. Feasibility Study

   Once you analyze the requirements and plan the software product, paperwork is needed to optimize requirements analysis and maintain a record of the solution’s development. The feasibility design document specification is often known as SRS (Software Requirement Specification) document and is to be understood by software developers thoroughly.

   The key aim of this stage in software development lifecycle (SDLC) – feasibility study – is to evaluate whether or not the proposed project is feasible in the specific areas below.

   • Check Economic Viability: Is the proposed project within the budget?
   • Test Organizational Compatibility: Is the software compatible with the organization’s policies?
   • Identify Operational Efficiency: Can the problem be addressed within the background of the customer utilizing the existing and proposed program?
   • Verify Technical Capability: Does the existing computer system and resources available in organizations have the capabilities to solve the problem?
   • Review Timeframe Functionality: Will the software project be completed under the proposed period?

   Through this stage conducting the feasibility test and addressing all these queries, you would attain a viable software plan which is ready for design – our next phase of SDLC that is design.

3. Designing

   The next section of SDLC defines, in-depth, the required criteria, functions, and operations that must be designed based on the SRS (software requirement specification) document. The goal of development processes is to turn the business specifications defined in previous SDLC phases into a comprehensive method that is practical, scalable, and value-added to the software organization when the development starts by the developer.

   This phase primarily includes two activities such as,

   • Design IT infrastructure: It includes software application logic, interface design, user interface (UX / UI design), database design specification (data storage and DB access), etc.
   • Design the system model : It includes a data transfer dictionary, process diagram, screen layout diagrams, tables of business rules, prototype, etc.

   Now, to conduct any software architecture and design there has to be a certain principle and design specification so that the software engineer can navigate the design process easier. Consider the below-mentioned principles to follow in third stage of SDLC.

   1. The design must be traceable to the method.
   2. The design must be standardized and integrative for navigation purposes.
   3. The design must be architecture to handle the shift.
   4. The design must be measured while creating a high-quality software application.
   5. The design must be conflict and error-free.

   After the design, the development phase in the SDLC begins.

4. Development

   In software development stages, the real work begins now – you need a software development company, to do the coding for you. When the software development phase starts, the planned quality software framework is to be split into different modules and assigned to the programmer.

   Dedicated software developers would then write the code according to selected programming languages.

   Picking a source control code management for programming language or access control program in this entire SDLC process would be a great help to developers in monitoring design improvements for code. It frequently helps to maintain compatibility between different software development team ventures and modules to ensure that aim code targets are achieved.

   Coding may include various kinds of tasks such as,

   • Finishing or brushing up coding skills in SDLC.
   • Finding project failure point and errors, and operating bug fixes of code.
   • Wait for code test results.
   • Compile code to run an application.

   Once development is done, the QA phase takes command in the SDLC.

5. Testing

   Once the development stage and coding are completed according to coding guidelines, the software system testing phase comes into the picture. A professional in quality assurance requirements (QA) will usually conduct the testing to decide whether the product presented satisfies the original collection of company objectives or not.

   In specific, testing may be repeated to check for strengths, defects, weaknesses, failure, deficiencies, and interoperability for programming languages and the system status. This test is performed by the software testing team until the end user sees fit. Another extent of this phase is life-cycle assessment, therefore, guaranteeing that the program is implemented satisfactorily.

   This code test plan phase can be classified into various subtasks and is to be conducted by quality assurance engineers on a repeat basis until the product integrity meets the high-quality levels specified in the SRS (software requirement specification).

   If all the tests are passed from unit testing to the UAT test by your software, then implementation becomes the next stage in the SDLC process.

6. Implementation

   As the performance testing meets customer expectations, the software needs to be made available for the end-users in this phase. The SDLC implementation stage deal with directing the final activation of the system for the client where typically the program passes to application configuration validation (User Acceptance Testing).

   The software deployment phase is one of the stages that helps one to see how the product performs and works for the consumer according to their needs through various comments, surveys, interviews, domain experts, subject matter experts, questionnaires, the newsletter, form, and articles.

   It is the hit or miss process where businesses need to gain overall customer approvals for the minimum viable product and the user must tell you whether or not the product is good enough for the eventual release development cycles.

7. Operation and Maintenance

   The final phase of the SDLC is operation and maintenance. Once the user accepts the product, it is ready for the commercial release and if certain bugs, a defect, or errors are found, it is necessary to fix them to ensure that the program runs smoothly. Another task to be carried by developers in the maintenance stage is to upgrade the software in the new version for maintenance and competition purposes. Once you upgrade the software into a new version, enhance those features for high-quality assurance requirements.

   The systems development life cycle (SDLC) phases subset the stage and establish a target with which engineers start a plan off. Essentially, it is designed to create software products more efficiently and with a few setbacks when necessary to use.

   So these are the core 7 phases of the software development life cycle (SDLC) that help developers and project managers for developing software applications within deadlines matching the business requirements.
   

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Now that you are aware of steps of the software development life cycle, let’s move to the SDLC methodologies and models.

8 Different Software Development Methodologies

Below we have covered all popular SDLC models with their working functionalities and pros/cons.

1. Waterfall Model

   Let’s understand first what the waterfall model is. The waterfall methodology is one of the longest-surviving application development life cycle (ADLC) models. It requires a hierarchical framework that demands the specification of all device parameters at the very beginning of a project.

   How does Waterfall model work? 
   The design of the waterfall model of the SDLC approach works in various ways that all the phases and stages flow through each other. That means the next step begins by developers only after the specified goal set for the previous phase is met. So in this SDLC method, there are no chances for overlaps. Waterfall methodology involves the planning stage, requirement gathering stage, designing, code implementation stage, building stage, testing , deployment environment, and maintenance phase.

   When to use Waterfall model?

   • When the software specifications are recorded quite well, and transparent and set.
   • When the product range description is consistent and not ambiguous.
   • When technology is not complex and hard to use.
   • When tools are sufficiently available with the requisite skills to help the enterprises.
   • When IT project planning is not long.

   If your software project meets the above criteria, you can apply waterfall model to the development process. However, every SDLC method has its pros and cons. Here is the list of important aspects you can take into consideration when choosing waterfall model.

   Pros

   Cons

   It is simple to use and understand. It produces high-quality software. It is simple to handle because of platform stiffness. Phases and stages can be processed and completed at a time. Functions best with smaller deliverables initiatives. It is easy to maintain design documents for the process and result in measures quickly. Tasks are simple to organize in Waterfall SDLC. Clearly defined stages and files of documents.

   There is high instability.  Not a suitable framework for dynamic tasks.  It’s hard to go back to any phase when it’s complete. The weak patterns for lengthy and protracted programs.  Not appropriate for programs where there is a low to large chance of adjustments to specifications. Hard to monitor progress in Waterfall SDLC method.

2. Iterative Model

   The iterative SDLC approach, in tiny steps, takes the waterfall paradigm and loops around it many times instead of extending an entire project. Meaning, this method begins with a basic implementation stage of a specific collection of program specifications and then iteratively improves the developing iterations before the entire framework is introduced and then ready for delivery.

   How does Iterative model work? 

   The iterative SDLC model is best viewed as a cyclical process. It involves a small number of steps that are replicated over and over after an initial preparation process. With each iteration of the loop, it advances incrementally and iterates on the program. Improvements are being identified and introduced easily during each iteration enabling the next step iteration to be at least a bit stronger than the last iteration.

   When to use Iterative model? 

   • When the full-system specifications are well recognized.
   • When there’s a time to the market constraint.
   • When the application development staff and team members are utilizing a modern platform and improving when operating on the launch.
   • When assets with skill sets needed are not accessible.
   • When some features of the high risks can alter in the future.

   If you see, the great aspect of this approach is that at a very early stage of the development processes of SDLC, there is a functioning development life cycle model of the system which makes it easier to identify functional or design document flaws. However, it is suitable only for the large software development process. For more details, understand the below-mentioned pros and cons.

   Pros

   Cons

   Results are to be collected regularly and early. You may schedule parallel growth. This SDLC is tangible. Change the variety/specifications to be less expensive and involve less cost. It’s quick to check and debug through smaller iterations. Easy to handle degree risks in this SDLC. The operational outputs are provided at any step. Examination of the risks is easier. Operating time is much lower. The each stage in this SDLC clearly identified.

   Require more resources. Require greater cloud management attention. Increments may need a complete system definition. It is not ideal for small software product development. Complexity in operations is higher in iterative SDLC. Highly trained personnel are required for the evaluation of risks. The success of models is heavily contingent on the operations of analytics, tutorial, and insight.

3. Spiral Model

   This SDLC method was first defined in his 1986 paper by Barry Boehm. The spiral methodology can be looked at as the hybrid method of a waterfall process, and an iterative process. Each phase of the SDLC spiral method starts with a design purpose and ends with the customer reviewing the growth. The spiral model approach helps software programmers teams to follow the software development life cycle (SDLC)methodology depending on the project’s danger trends.

   How does Spiral model work? 
   There are four stages to the spiral SDLC model pattern. In loops called Spirals, a project constantly passes through the below-mentioned stages.

   1. The SDLC process starts with the stage consisting of a selection of company criteria in the spiraling baseline. The definition of software descriptions, module specifications, and machine requirements gathering – everything is to be achieved in this step.
   2. The design phase starts in the reference spiral model with the conceptual code framework by design development teams.
   3. A construction phase is also known as deployment phase steps about-the proof of concept that has to be produced in this stage where the plan is developed to place customer satisfaction and friends suggestions and user feedback.
   4. The final stage is to carry out a risk assessment. Calculate and track technological viability and risk reduction, such as slip-pages times and backlog costs. After that, improve based on customer opinions.

   When to use Spiral model? 

   • When there is a limitation on the expenditure and risk management is relevant.
   • When risk analysis stands between medium to high.
   • When the software product development are for long-term participation.
   • When the users are not sure of the requirements.
   • When business requirements are complicated.

   In addition, when your tech project has complicated specifications or plans big changes during your mid-to-high-risk phase, then the spiral SDLC method will be your software developent workflow. But before choosing the development life cycle model, look at the below-mentioned pros and cons once that will help you to choose the best option.

   Pros	Cons
   It will meet evolving end-user requirements. Let you use prototypes for the software development lifecycle (SDLC). Specifications may be more reliably recorded. Consumers can look early on at the program. Design can be separated into smaller components and code is clear. The unsafe components installation possibility and opportunities lead to boost risk control.	Management becomes more difficult. Can not decide on when the plan will be completed. Not ideal for projects at medium or low risks. The method service is complex and large and no security. The spiral SDLC can go on and on. It might not end ever. Excessive paperwork is needed for vast numbers of intermediate levels and updates.

4. V-Shaped Model

   The V-model is an extension of the classic waterfall techniques and known as a verification and validation model. The reason it is called the v-model, is the phases and stages are flipped upwards after the coding point in a v-shape. The SDLC method has a rather rigid method that means once you complete the process for one phase, then only the next stage development starts. This means you can’t proceed further until you finish the software development process for the initial stage. It is a step by step approach from planning to deployment.

   How does V model work? 
   If we break down the V-shaped model into various phases of the software lifecycle (SDLC), it includes 3 main phases such as,

   1. Verification Phase – This stage mainly covers business requirement analysis, system design phase, product architecture design phase, and module-design phase. Business requirement analysis is a phase in which product requirements are considered from the client’s viewpoint.

      System design is the process where you will be required to design the complete system after considering customers’ requirements in the V-shaped SDLC model.

      Architecture design (High-level design) scheduling by product architects is for integration high-level design and documentation basis on the transmission and connectivity of data processing with the internal modules and with other management systems.

      Module design (Low-level design) is a process where a unit check is to be performed based on the internal configurations to render it error-free and if at all there is, it helps to operate bug fixes and errors.

   2. Coding Phase – In this stage of V-model SDLC, depending on machine equipment and technical specifications the best fitting PHP programming language is to be determined and coding takes place. This is also known as the code implementation phase of the SDLC stages.
   3. Validation Phase – This stage mainly includes unit tests, integration testing, system testing, and acceptance testing.

      Unit testing is to be conducted to establish the Unit Test Plans to eliminate bugs at individual program level which is source code level or unit level.

      Integration testing is to be conducted to establish Integration Test Plans to validate that groups will coexist and interact within themselves, produced and evaluated separately, during the architecture phase.

      System testing is to be conducted to establish System Test Plans to verify that the application’s established requirements are achieved.

      Acceptance testing is to be conducted to establish User Acceptance Test Plans to make sure that the system is finally ready for the computing world.

   When to use V-shaped model? 

   • When the project is for a short term period.
   • When the software specifications are not vague or unclear.
   • When technology isn’t fluid.

   The disciplined V Model is, however, very easy to use as applied in a defined stage when it comes to implementation and handling. So if you are looking forward to applying this SDLC method in your business systems, you also need to see the advantages and drawbacks it consists of.

   Pros	Cons
   It is a highly structured process of software development so that it can be executed stages one by one at a time. It can be great for staging small software development projects. High-level design usability. Clear and intuitive services. With each stage of the SDLC, there are variable outcomes and a process of requirement analysis.	It consists of greater risk. It is not a suitable example for dynamic tasks or object-oriented ones. Can not go back and adjust the function. It is inflexible in nature. The V-shaped SDLC model lacks accuracy. It is inefficient for the software testing phase.

5. Big-Bang Model

   The Big Bang model, unlike nearly all other common development life cycle (SDLC) models, is remarkable. Why? It needs practically no preparation, stages, coordination, best practices, or traditional procedures. It is the concept of simply beginning the process right now, at this moment, with no organized frame-work or even organization.

   Now you might be wondering if the SDLC method doesn’t possess any process then why do we even need to think of this. But let me tell you, while most companies would aim for a standard phased implementation with a new launch, in some cases, gradually implementing a new program may not be within a feasibility study. Especially when you are developing a radically different version of a product or release. In scenarios like this, the only rational unified process is an immediate release like pressing a button. This is called big bang adoption.

   How does Big Band model work? 
   As I mentioned this SDLC method doesn’t follow any procedure so the software development life cycle begins by developers only with inputs with best practices that contain the necessary money and resources, and the outcome is the produced software that may or may not fulfill the customer requirements.

   When to use Big-Bang model? 

   • When the proposal is short.
   • When the project development team is small.
   • When the project doesn’t require any planning or maybe little planning.
   • When the necessary improvements may or may not require a full redesign of the program.
   • When the software development process requirements are not clear.
   • When the release time is not certain.

   Like other software development life cycle (SDLC) models, this development model also contains the various elements of benefit and the drawback that are as follows.

   Pros	Cons
   It is one of the simplest SDLC methods & quick to implement. This calls for less planning. This calls for fewer resources. Support small-scale projects. They’re cost-effective. Easy to manage and quick cost estimates. There’s no development time limit.	This is not ideal for large projects or for complex ones. It’s extremely risky. It has inherent ambiguity. It is an inexpensive model.

6. Agile Model

   The Agile SDLC model is the complete opposite of the Waterfall model. In the old days, the iterative waterfall model was famous for completing a project. But the software developer and project manager had to face numerous problems and difficulties following this pattern, particularly when customers request a change and modification in handling or there is an upgrade in system requirement. So in order to reduce these challenges and disadvantages in older versions, they presented the concept with a label Agile Software Development. Although, Agile model is also a combination of iterative and incremental model as it has phases that matches with both these SDLC methodologies.

   The agile model is a application development planning process that encourages ongoing development and evaluating iteration during stages of software development life cycle (SDLC). It focuses on software products robustness.

   How does Agile model work? 
   Agile SDLC models split up the project into tiny sequential constructions known as a sprint series. All builds come in iterations and events. Usually, each replication of sprints lasts from about one to three weeks. Every implementation stage requires cross-functional teams operating concurrently in various areas such as the planning stage, requirement analysis phase, designing stage, code implementation stage, building stage, testing stage, and acceptance testing phase.

   There are various forms of Agile SDLC models that software development companies use like,

   • Scrum
   • Lean development
   • Crystal software development methodologies (CM)
   • Dynamic systems development method (DSDM)
   • Feature-driven development (FDD)
   • Extreme programming (tools) (XP)

   Out of all scrum, lean development, and XP are the most common models for the SDLC process.

   When to use Agile model?

   • When the plan is for a short period.
   • When the departments and organization team size is small.
   • When the code development speed is required.
   • When flexibility is essential.

   In better words, Agile SDLC method is best to use when there is a change in business dynamics, competitor development and you need a method that performs between transformation and input. For more understanding, look at the below-mentioned pros and cons of Agile SDLC.

   Pros

   Cons

   It is one of the practical models for designing the program. Enhancements of communication and training across software development teams. The limited requirements of specifications for the capital. Appropriate for demands setup or changing. Advance directives for early part-time work and completion of the project are early. Great fit when there’s a constant evolution of climates. Limited guidelines, efficient usage of the documents. Allows instant development through software programming tools.

   Not tailored to dealing with complex dependencies. Greater sustainability risk and uncertainty. Strict distribution source control determines the distance, the features to be shipped, and the time-limit changes. It’s highly reliant on client involvement and location. Need high maintenance in the Agile SDLC.

7. Model 7. RAD Model

   Rapid-Application Development (RAD), also known as Rapid-Application Building (RAB), is also a common phrase used to apply to agile software development models. RAD solutions to application development typically put less focus on preparation and more focus on an agile development life cycle.

   RAD is a technique for software development, utilizing limited preparation in lieu of rapid prototyping. A prototype is a technically identical operating model of one part of the product visibility. RAD software development projects generally adopt the iterative and the increment model and include limited development teams composed of engineers, software industry experts, client representation, and other IT tools collaboration on their parts or concepts gradually.

   How does RAD model work? 
   RAD SDLC model divides the processes of research, design, construct, and testing phase into a sequence of short, iterative SDLC. It involves phases and stages such as,

   1. Business Analysis – A full business requirement analysis is carried out to find the vital business information.
   2. Data Analysis – The data gained by developers during the business analysis process is checked and analyzed to create collections of essential business data items.
   3. Process Analysis – Convert the data object sets identified in the data analysis process as per the business model.
   4. Application development – Coding is conducted by the engineers and software developers, according to the coding guidelines.
   5. Testing – The data flow, interfaces, code-quality testing for all the modules must be carefully checked with complete software development coverage.

   When to use RAD model? 

   • When there is a wide supply of modeling designers.
   • When industrial expertise with appropriate market and production environment experience is available.
   • When the spend is in the budget to use digital software for code creation.

   Important: RAD model allows for a quick development environment because it decreases the total software development life cycle (SDLC) time due to product recyclability and concurrent growth. Let’s check the pros and cons of RAD SDLC.

   Pros

   Cons

   It can handle new conditions, scope, and situations. One can calculate progress from the planning stage to deployment. With the use of efficient RAD software development models, the iteration period may be limited. Productivity in a limited period, for fewer participants. The time of the software development lifecycle (SDLC) stage is reduced. Increases Product Reusability. Fast initial evaluations are in the software development process. Encouraging input and response from

   Only frameworks can be designed using RAD that can be modularised. Highly qualified developers/designers and business analysts are needed. High dependence on skills and commitment to modeling. It is very large and inapplicable to cheaper tasks such as simulation costs and automatic code creation costs. Complexity in administration is greater. Suitable for only component-based management systems.

8. Prototype Model

   Prototyping is a software development process model that is used for software development. The software development prototyping model’s principal aim is to meet the desires of the consumer. Developers execute the prototyping concept to obtain this, then submit it to the consumer and other parties for assessment.

   The prototype model is one of the working software development models with very restricted features. The implementation stage does not necessarily contain the same reasoning found in the final product and is an additional step to be taken into account under the calculation of steps.

   How does Prototype model work? 
   In this stage, prototypes proceed until the product meets the consumers’ expectations. The prototype undergoes various kind of phases and stages at each iteration such as,

   1. Basic requirement identification – This stage helps to recognize the very basic specifications of the product mainly in the manner of the user interfaces.
   2. Develop initial Prototype – In this core point, where the very specific specifications are outlined and user interfaces are given, the actual prototype is created.
   3. Prototype review – The developed prototype is then introduced to the user and other relevant project managers and domain experts through the form and questions for the review.
   4. Monitor and evaluation phase – Project managers reviews, customer feedback, and suggestions are addressed and some discussions take place with actors such as time and budget constraints.

   When to use Prototype model? 

   • When developing systems that have high user communication levels.
   • When applications for business require users to fill out forms or move through various types of screens and articles before processing the results.
   • When the program does not require much processing of the data and input of everyone.

   Important: The prototype development process could be an extra overhead in such software development projects where the internal approaches are more as it may need lot of extra efforts. Furthermore, here are the pros and cons of Prototype SDLC model.

   Pros

   Cons

   Improved customer interaction and input with the app just prior to its launch. The consumers get a clearer view of the framework being built when an operating implementation of the program is shown. Reduces time and expense because we can spot the flaws much sooner. Faster customer input contributing to new ideas is now open. Required features may be quickly found.

   Risks of inadequate review of criteria due to over-reliance on the prototype. In experiments and real systems, users can become confused and have less scope. In reality, this example will lead to enhancements of the system’s complexity because the system’s reach may extend beyond the original development plan. Developers can try to reuse existing prototypes to create the actual device, even though it is technically impossible.

The Importance of SDLC Methodologies in IT

The software use proliferated in the late 70s and early 80s so it is not wrong to say that the area of software engineering is fairly young. But since then the different software development life cycle (SDLC) models have been successfully fulfilling the role of the software development activity in the software organization. How?

• This server serves as a plan reference for meeting customer needs.
• This provides a defined view of the system as the whole inception, its resources, segment, timeline, and objectives.
• Operation and performance evaluations help to make sure that the finished result is accurate and consistent.
• Control overbroad or complicated program improvement.
• This offers a context for a selection of typical activities in a production environment.
• SDLC life cycle lets you make sure the distribution to the people is accurate and within time.
• It provides power over the development process concurrency and decision making.
• Fast cost estimates and extension of existing programs.

Do you still have doubts about SDLC? Are you having any questions regarding SDLC methods? Check the following section where we answers a few to the most asked questions.

Choose the Right SDLC Model for Your Project Development

If you begin developing a new product and software as a startup, it’s important to follow the life cycle of the system development for a great impact and effectiveness. Because this way the project team is allowed to operate in a managed and well-organized atmosphere according to a systematic approach case to designing new software development solutions without any hassle.

However, when you select the approach to app development, it is highly essential to know what tool would be suitable for your products. Sometimes, you may find that more than one approach is suitable for your project management, so in this case, making a decision for selecting the appropriate approach is quite challenging. So if you find any problems with regard to the software development life cycle (SDLC) and choosing the best models, you can contact us at any time and our experts will reach you at earliest with the best solutions.