Software Development Life Cycle (SDLC) can be called a process; however, in its core, it is a model of software development that allows you to minimize development costs and maximize the final product quality. SDLC defines not only the steps one needs to make to complete the development but also hints at how to maintain and tweak a software system to ensure its highest efficiency in the future.

How and why SDLC works

SDLC is based on the years of practice and thousands of mistakes developers and managers have already made to guarantee the best results. It helps a client to lower development costs and at the same time get all the required functionality as fast as possible. A plan based on the SDLC principles removes all common pitfalls and eliminates excessive work in the development projects.

SDLC and its stages

Note that stages offered here can vary depending on your development goals and needs.

Project scope definition. Whether it is your project or you have a client who came to hire you, the scope definition is one of the essential elements in the whole process. The client defines the goals and the results they are willing to achieve while the development team, guided by a project manager (PM), carefully notes all the details to clarify the timeline and the list of requirements, as well as outline the number of experts needed to complete the project.

Planning. Once all communication with the customer is behind, and the PM clearly understands the scope of work, the planning time comes. This is where a senior developer can estimate how much time is needed for the project and how many team members should actually be involved. The UX/UI team also states what it will take to finalize the design of a project. Then QAs say their final word about the last checks. Based on all this information, the PM sets out a timeline for all teams with the milestones and goals to be completed at each stage. The final calculations on the price can also be communicated at this stage and hence finalized with the client.

Development. This is the easiest stage in terms of definition. All teams get down to business, coding, testing, and monitoring the system’s performance. This is the core of the whole project course hence the name of the stage.

Testing. After the software is delivered by the developers and the UX/UI designers, the QA team steps in to ensure that all functionalities, buttons, links, and processes in the software work as intended. The head of QAs also reviews the initial requirements and compares them with the final software so that the product serves the intended purpose. Once any bugs or discrepancies are identified, developers fix them, and testing begins again. Only when QAs give the green light, the PM can proceed to the next development stage.

Delivery or deployment. Both names suit this stage well. This is the moment when the client sees the final product and reviews all the work. Should any remarks appear, the development team fixes them. After both sides of the deal are happy, the software is deployed (pushed live).

Maintenance and support. This is not an obligatory stage of SDLC. It might not be applicable for outsourcing companies, while it is pretty common for the in-house development teams. After the rollout of the software, the development team keeps on working to maintain high performance, eliminate any bugs, deliver updates based on new requirements, and support end-users if required.

Software development life cycle examples

Now let’s move to how the model works in real life and how a development team goes through the cycle.

Project: New CMS

Project scope definition: the client already has a CMS and needs to update and improve the existing solution. The main request is the UI to be more intuitive to let even new team members easily manage and create new mobile solutions, websites, and intranets.

Planning: since the task is not the addition of a new feature but a complete re-development of the existing system, the Agile framework works best for such tasks. At every point of the process, every element can be updated, redesigned, and readjusted to fit the altered final goal.

Development: of course, during the development, everything may happen since the initial request is not clearly defined. But let’s assume that the developers turn the system towards a custom-made web framework as opposed to the open-source framework. This is justified by higher levels of content security. The UI team then enriches the front-end to make it more intuitive and user-friendly.

Testing: the testing process will usually look similar for all development projects. The QA team performs automated and manual tests to guarantee that the system works as designed and matches the customer’s requirements.

Delivery and deployment: in a perfect world, the new solution will be accepted by the client without any comments and hence will be deployed soon after testing.

Maintenance and support: whenever users report about any bugs or a client requests new features, the dev team gets back to the projects and fixes the problems while updating the system.

Project: Streaming app

Project scope definition: the client needs to develop an omnipresent streaming app that will allow customers to watch their streaming on any device (phones, tablets, OCs, laptops, TVs, and gaming consoles).

Planning: the dev team offers to work on Backbone.js to minimize the development costs and hence increase development productivity. Additional features are proposed to the client to maximize a smooth experience from the app (stream purchasing after its passing). After the approval from the client, the development team gets down to coding.

Development: the specific requirements allow the team to work fast and efficiently, delivering the app earlier than planned.

Testing: since the core development ends earlier, the Quality Assurance team has more time for testing. In the process, it appears that the app database does not accept users with identical first and last names. The bug is reported to the dev team and fixed within the timeframe.

Delivery and deployment: the customer is satisfied with the result but requests UI color change owing to the company’s rebranding strategy. The last adjustments are made, and the app is deployed.

Maintenance and support: the client refuses to receive any maintenance and support assistance.

The bottom line

The software development life cycle examples above demonstrate the versatility of the methodology and its effectiveness for projects of different scope and complexity. The important thing to remember about SDLC is that the overall success of software development within this framework heavily depends on the first two steps: scope definition and planning. Whenever the end-points or the expectations get accurately authorized by a client, the development team gets the possibility to prepare the final solution just as required without the need to jump back and fix or add any unexpected features.