Types of sdlc models in software engineering

This model is increasingly becoming popular as it can be built after understanding the needs. Uses: This model can be used for any software development that has user interaction. Rational Unified Process model fragments the development process in the inception phase, elaboration phase, construction and transition phase. Uses: Projects that are large-sized and carry high amount of risk prefer this model.

It is one of the software engineering models which do not adhere to a particular process per se. Uses: This methodology is best suited for small projects. It does not require high-level planning and it is an easy model. Rapid Application Development methodology does not require planning and best applied in projects that require customization from the customer. This model builds prototypes of functional modules which are incorporated into the software after completion.

The advantage of this model is that it is less time-taking, and also engages the customer. Their feedback is sought and the product is developed. RAD might fail, if the project cannot be divided into modules. Although there are many types of software development models which are applied across various development projects, the ideal model is applied depending on the project size and requirements.

Here is a statistical chart on cost comparison of the above-mentioned software models. The statistics for models with minor applications that encapsulate a thousand functions. The Waterfall model is comparatively an expensive software development model.

The other models are less in terms of cost. However, Waterfall is the most widely applied model in spite of the fact that it requires high cost. This website uses cookies so that we can provide you with the best user experience possible. Cookie information is stored in your browser and performs functions such as recognising you when you return to our website and helping our team to understand which sections of the website you find most interesting and useful.

Strictly Necessary Cookie should be enabled at all times so that we can save your preferences for cookie settings. If you disable this cookie, we will not be able to save your preferences. This means that every time you visit this website you will need to enable or disable cookies again. Software Development. While planning all details, the project manager should choose the model according to the team size, working schedule, etc.

For example, all software development life cycle models under the adaptive type will not be suitable for large teams and yield results only in groups of approximately 5 to 10 people. There are many different SDLC models in software engineering, and they vary according to many factors. Still, the sequence of software life cycle phases usually remains the same, with a few exceptions. Requirement gathering and analysis are crucial for a software life cycle.

There are many people taking part in this stage and many processes going on. Each software development life cycle model starts with the analysis, in which the stakeholders of the process discuss the requirements for the final product. The goal of this stage is the detailed definition of the system requirements. Besides, it is necessary to ensure that all the process participants clearly understand the tasks and how specialists will implement every requirement.

Often, the discussion involves the QA specialists who can interrupt the process with the adjustments even during the development stage if it is necessary. Also, a project manager defines the technologies used in the project, team load, limitations, time frames, and budget.

The most appropriate project decisions are made according to the specified requirements. Business analysts perform the most crucial part of the work at this stage. They actively communicate with a client, conduct meetings, and ask questions. Along with the project manager, the business analyst does the cost estimate and defines the scope of work. Depending on the software development model, the requirements may be very strict or just sufficient to start the work.

The project manager, in turn, should form the initial working plan and split all tasks correctly between the team members.

During this stage, specialists form the basis needed for further development. It includes a Software Requirement Specification document, application wireframes, mockups, and a prototype optional. Requirement analysis should be approached seriously by the specialists because it is a foundation of all further work.

The system design stage is practically an extended version of the plan developed during the first phase. So, all gathered info about the product is being analyzed and systematized. The information received during the requirement analysis stage was primarily described in words, and at the design stage, the plan is amended with the technical details. So, the developers are designing the architecture at this phase of the software life cycle.

All the different technical questions that may appear at this stage are discussed by all the stakeholders, including the customer. Specialists who work actively at this phase are software engineers, system architects, database specialists, designers. And of course, BA, PM, and tech leads remain a permanent part of the software development process. Each time a system component is created, it should be documented at once. After the requirements are approved, the process goes to the next stage — actual development.

It is the most lengthy stage of the SDLC. Up to this point, all necessary information about the product is ready, and all details are thought out and designed. So, they start to write the source code while keeping in mind previously defined requirements. The system administrators adjust the software environment. Frontend programmers develop the user interface of the program and the logic for its interaction with the server. Programmers actively communicate with the designers because the functionality must be consistent with the design.

Apart from the developers, PM plays an essential role by controlling that the documentation, system design, and other components fall under the relevant standards. He is also responsible for managing teams and consistent product delivery.

So, before moving on to the next phase, programmers need to code back-end, front-end, databases, APIs, integrations, etc. After everything described is completed, the team moves to the testing stage. The testing phase includes the debugging process. All the code flaws missed during the development are detected here. QA specialists document them and pass them back to the developers for fixing. The testing process repeats until all the critical issues are removed, and the software workflow is stable.

The activity during this phase may vary depending on the testing types adopted by the QA engineers. They do manual testing with the help of such methods:. If QA specialists opt for automated testing, they use numerous frameworks and solutions that ease the process.

QA engineers can receive some testing results only after the demo version of an app is published, and they can interact with it as users. The data based on it helps to understand whether the product corresponds to business requirements as well as to the technical ones.

When the program is finalized and has no critical issues, it is time to launch it for the end-users. After the initial program version release, the tech support team joins. This department gathers user feedback for further analysis.

They also consult and support users during the exploitation. In Agile development, a DevOps engineer is responsible for app releases and deployments.

Among their responsibilities there are:. DevOps engineers use various tools to achieve faster product deployment — for example, Jenkins , Docker , Git , and others. Sometimes, the DevOps team includes from 3 to 5 specialists.

So that, separate people are in charge of release management, automation, QA overseeing, and security management. But, in some cases, only one high-skilled person takes on all of these responsibilities. A product manager is responsible for analyzing the data gathered based on the first feedback from real users. So that a team can make conclusions about which practices were successful and which ones they better replace.

This information helps a business analyst or a product manager understand whether all features are necessary or missing. It provides them with a clear picture of what people want. So, the application adjustments are not uncommon after the initial release.

Maintenance includes two types of work if we divide it roughly: supporting initially created functionality and adding new features. Usually, it involves the maintenance agreement, where the responsibilities of a software provider are strictly defined. It targets more the support of the existing features and outlines how many online consultations and departures to the client are included, what time is suitable for contacting the team, and other details.

However, this document also covers the frequency of software updates. When it comes to the technical side of the issue, a project manager analyzes the feedback after the initial release and assigns the developers to fix bugs and add updates. Significant updates are made according to a particular schedule, and some minor changes are implemented by a DevOps engineer frequently.

While programmers fix bugs and add new features, a DevOps specialist plans, and schedules the ongoing release. Curious to find out what specialists take part in each stage, how long it takes, and how much it costs? There are two core software development life cycle models: heavyweight predictive and lightweight agile. Heavyweight processes imply that the scope of work is predefined in advance. They require a significant contribution from the programmers and weighty documentation.

Traditionally, companies chose a heavyweight approach for streamlining and organizing extensive projects. However, now this type of SDLC models has lost its popularity. It decreases project efficiency because of the unnecessary bureaucracy implied. Today, it is replaced by lightweight or agile processes, also called adaptive. They are a good compromise between overly strict discipline and its total absence.

Agile methodologies require a much smaller amount of documentation in terms of a software life cycle. For example, an adaptive approach considers various customer requirements, such as the necessity of constant application modifications. Predictive SDLC models, in turn, are only growing in complexity with the emergence of unplanned changes. Heavyweight methodologies are pertinent in the context of strictly defined requirements and large teams of specialists. Agile tactics are best implemented in terms of frequent amendments to the initial plan and relatively small groups up to 10 people working in one team.

There are many more options, but these are the most common ones. Among different SDLC models and methodologies, adaptive agile are the brightest candidates nowadays.

The agile approach opens up new possibilities for specialists, enables more flexibility, and puts the communication between people ahead of the blind plan following. Realizations of Agile models include:. What is Agile Testing? Process, Methodology and Strategies. What is Data Flow Testing? Application, Examples and Strategies. Black Box Testing Techniques with Examples.

Now Let us go through the various software testing models and their benefits: 1. Waterfall Model This is the most basic software development life cycle process which is followed broadly in the industry. Advantages Easy to implement and maintain. The initial phase of rigorous scrutiny of requirements and systems helps in saving time later in the developmental phase The requirement of resources is minimal and testing is done after completion of each phase.

Disadvantages It is not possible to alter or update requirements You cannot make changes once you are into the next phase. Cannot start the next phase until the previous phase is completed 2. V Model This model is widely recognized as superior to waterfall model. Advantages Easy to use the model since testing activities like planning and test designing are done before coding Saves time and enhances chances of success. Defects are mostly found at an early stage and downward flow of defects is generally avoided Disadvantages It is a rigid model Early prototypes of the product are not available since the software is developed during the implementation phase If there are changes in the midway, then the test document needs to be updated 3.

Agile model In this SDLC model requirements and solutions evolve through collaboration between various cross functional teams. Advantages Ensure customer satisfaction with rapid and continuous development of deliverables.

It is a flexible model as customers, developers and testers continuously interact with each other Working software can be developed quickly and product can be adapted to changing requirements regularly Disadvantages In large and complex software development cases it becomes difficult to assess the effort required at the beginning of the cycle Due to continuous interaction with the customer, the project can go off track if the customer is not clear about the goals 4.

Spiral model It is more like the Agile model , but with more emphasis on risk analysis. Advantages Risk avoidance chance is enhanced due to the importance on risk analysis. Its a good model for complex and large systems. Depending on the changed circumstances additional functionalities can be added later on Software is produced early in the cycle Disadvantages Its a costly model and requires highly specialized expertise in risk analysis It does not work well in simpler projects 5.

Rational Unified Process This model also consists of four phases, each of which is organized into a number of separate iterations. Advantages With an emphasis on accurate documentation this model is able to resolve risks associated with changing requirements of the client Integration takes less time as the process goes on throughout the SDLC.

Disadvantages The biggest disadvantage is that the team members need to be experts in their niche. In big projects such continuous integration, it might give rise to confusions 6. Rapid application development This is another incremental model like the Agile model. Advantages The development time is reduced due to simultaneous development of components and the components can be reused A lot of integration issues are resolved due to integration from the initial stage Disadvantages It requires a strong team of highly capable developers with individual efficacy in identifying business requirements It is a module based model, so systems that can be modularized can only be developed in this model As the cost is high, the model is not suitable for cheaper projects Conclusion The above mentioned software testing models are a part of the SDLC process.