You cannot work on 2 or more development phases at the same time. The Software Development Life Cycle can be further broken down into 7 common phases that most systematic and planned software development goes through. The release of Version 1 of the Software Assurance Maturity Model and reports are the use of SSF in nine organizations indicate a new level of awareness of the value of embedding security into the SDLC. Organizations are showing increased response to security, but there is still a long way to go before considerations of security in the SDLC can be considered mainstream. The Veracode survey indicated 34% of the organizations included in the survey actively address security within the SDLC, but only 13% know the security quality of their business code .

Often it can be hard to determine what the most important engineering concepts and terms are, and even once you’ve identified them you still need to understand what they mean. To help you learn and understand key engineering terms and concepts, we’ve identified some of the most important ones and provided detailed definitions for them, written and compiled by Chegg experts. Improving the quality of the software that the organization delivers. In addition, HLD should contain information about resources, technologies, and information on possible risks as well as ways to recover the system in case of failure. Needs to review the security of your connection before proceeding. This stage gives a clearer picture of the scope of the entire project and the anticipated issues, opportunities, and directives which triggered the project.

The next phase is about to bring down all the knowledge of requirements, analysis, and design of the software project. This phase is the product of the last two, like inputs from the customer and requirement gathering. This is accomplished through “SRS”- Software Requirement Specification document which contains all the product requirements to be constructed and developed during the project life cycle. The coding or development phase also defines the tools and technologies to be used by professional software developers. Debugging tools, compilers, interpreters, and other coding platforms are made readily available. The advantages of keeping software development stages as per a standard life cycle are many, a few being mentioned below.

definition of software life cycle model

So, there are verification phases of SDLC on the side and the validation phase on the other side. During design, the architecture, user interface, security, etc. will be decided upon. The planning phase is when the software’s requirements and purpose are defined. Though Agile software development has higher values, it normally adopts the iterative and incremental method to achieve those values. The best tools and methods take care of the easy problems, allowing you to focus on the difficult problems. The process is based on the strong belief that each step should serve a clear purpose and be carried out using the most rigorous techniques available to address that particular problem.

Software Development Life Cycle (SDLC)

Next step is to bring down whole knowledge of requirements and analysis on the desk and design the software product. The inputs from users and information gathered in requirement gathering phase are the inputs of this step. The output of this step comes in the form of two designs; logical design and physical design. Engineers produce meta-data and data dictionaries, logical diagrams, data-flow diagrams and in some cases pseudo codes. The entire software development life cycle may be applied to correcting any bugs detected in the system. Routine software updates and patching operations are part of this phase.

Waterfall model is the simplest model of software development paradigm. It says the all the phases of SDLC will function one after another in linear manner. That is, when the first phase is finished then only the second phase will start and so on. The implementation of software design starts in terms of writing program code in the suitable programming language and developing error-free executable programs efficiently. The testing phase is essential in ensuring a system works properly. It is the most important phase in developing quality, functional software.


In conclusion, different models of the software development life cycle are applicable to different projects and applications. The intended use and requirements of the software can help to decide which model to use. The available time and resources can also be a deciding factor.

definition of software life cycle model

If required, the users are trained on, or aided with the documentation on how to operate the software and how to keep the software operational. The software is maintained timely by updating the code according to the changes taking place in user end environment or technology. This phase may face challenges from hidden bugs and real-world unidentified problems. Above all, the planning phase includes determining if the project is feasible with existing resources. To decide if the project can be completed within the desired budget with the current team.

What Does Software Development Life Cycle Model (SDLC) Mean?

It ensures that the end product is able to meet the customer’s expectations and fits in the overall budget. Hence, it’s vital for a software developer to have prior knowledge of this software development process. This model leads the software development process in iterations.

The SDLC consists of individual steps that are required to plan, develop, and implement software programming. Each step is vital in the successful creation and roll-out of a system. Every process can have several layers that all play essential roles in the process. Once the requirement analysis is done, the next stage is to certainly represent and document the software requirements and get them accepted from the project stakeholders.

  • An extra security push includes a final code review of new as well as legacy code during the verification phase.
  • CMMI-ACQ provides improvement guidance to acquisition organizations for initiating and managing the acquisition of products and services.
  • After that subsequent cycle may begin before the previous cycle is complete.
  • Because the software development lifecycle model requires the development team to complete each phase before moving on to the next, it helps ensure problems don’t become compounded during the process.
  • However, the V-shaped model still follows a sequential transition between phases as the next phase can only begin after the current one ends.

In general, the term means the activities, methods, and procedures that provide confidence in the security-related properties and functions of a developed solution. It is the fastest way to finish the project with the least bugs as it provides the chance to alter the code and database structures. The code is tested to make sure it is free of bugs, adheres to the client requirements and correctly interfaces with other software products together with the underlying hardware. SDLC done right can allow the highest level of management control and documentation. All parties agree on the goal upfront and see a clear plan for arriving at that goal. The most flexible of the SDLC models, the spiral model is similar to the iterative model in its emphasis on repetition.

And as all frameworks, it has its standard steps and procedures. In this article we’ll go through the definition of software development cycle. We’ll address its models, then switch to different SDLC phases and go through those in a bit more detail. This method lets you build products using short cycles (“sprints”), where each sprint ends with a working product with a limited number of features. Each sprint includes design, development, testing, and deployment. The requirements are divided into groups at the start of the project.

The software development phases consist of all important documentation, technology, market research, budget analysis, and feasibility of the project. Software Development Life Cycle refers to a systematic procedure to build software that warrants superior quality and scalability of the product. Standard software development requirements management aims to cater to the business objectives defined and narrated by clients so that the final product is satisfactory and fulfills the needs of the investment. The benefit of this approach is that product owners can see the results of each short cycle, provide their feedback, and make corrections if needed. At the beginning of the next cycle, software developers revise the previous version of the product and present it for the next round of feedback. As such, the Agile software development life cycle is known as a continuous process.

During this phase, QA and testing team may find some bugs/defects which they communicate to developers. The development team fixes the bug and send back to QA for a re-test. This process continues until the software is bug-free, stable, and working according to the business needs of that system. An Agile model is an approach that combines iterative and incremental processes in one development methodology.

Others have started to explore the integration of security assurance with Agile Methods . If you don’t, verification and validation can take up to 60% of the total effort. Even doubling the effort on coding will be worthwhile if it reduces the burden of verification by as little as 20%. Better yet, deploy techniques that make it difficult to introduce errors in the first place. The most expensive is to let your customers find them for you. Establish and maintain independent reporting of safety and security status and issues.

Software Development Life Cycle Models

The Agile Security Forum was initiated in 2005 to provide a focal point for industry-wide collaboration. Additional information about the Forum, as well as other papers expanding on the approaches to security being taken in conjunction with Agile, is available on the Forum website. After each change, verify that the updated system behaves according to its updated specification. Making small changes makes the software much easier to verify. Please include attribution to with this graphic. Note, that you must complete all the activities on the left side with a verification.

Overview on software life cycle processes

Software developers use coding guidelines and various tools to write and implement code. The result of this phase is a working software product and a Source Code Document. The waterfall remains the dominant model for these definition of software life cycle model early software development life cycle frameworks. In the waterfall model, everything in one stage is completed before you move to the next stage. All planning gets completed before the project moves to implementation.

As two utterly different approaches to software development, Agile and Waterfall are suitable for different kinds of projects. The Waterfall model is a good solution for projects with stable and defined requirements, whereas Agile is best suited for projects with varying requirements. Software development life cycle is a series of steps that a team of software developers must follow to develop and maintain software.

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While the TCMM/TSM is not widely used today, it nevertheless remains a source of information on processes for developing secure software. Security assurance usually also includes activities for the requirements, design, implementation, testing, release, and maintenance phases of an SDLC. All of the above helps to show why the software development life cycle is important and how it has evolved over time.

Requirement collection and analysis phase

Proper planning and execution are the key components of a successful software development process. Software Development Life Cycle is the common term to summarize these 6 stages. The software development life cycle is cyclical in nature as the process is ongoing.

He submits his request to the service providing organization in writing. Each iteration starts with a small set of requirements and goes through the development phase for those set of requirements. It moves on a cyclical continuum of completing incremental pieces of a larger project. The individual pieces can be completed simultaneously in small chunks. This allows for flexibility if the project needs to grow along the process.