The system development life cycle (SDLC) is an iterative, structured, and multistep process that is used by teams to create high-quality information systems. It involves the activities of planning, analysis, designing, building, testing, deploying, and maintaining a system that meets or exceeds client expectations.
SDLC has been around since the 1960s—a time when teams were more centralized. As the information technology sphere continues to evolve, the SDLC has been changed to keep up with the ever-changing demands in system development.
Importance of the SDLC
Having a system development life cycle is essential as it serves as a platform to transform an idea into a functional and fully-operational system. In addition to covering the technical aspects of an IT system’s development, the SDLC also encompasses certain activities such as user experience, security regulation compliance, procedure development, policy development, and change in management.
Another key reason why teams need to leverage an SDLC is, it's important that they plan ahead of time and examine the structured goals and stages of a specific project.
It’s worth noting that goal-oriented processes do not adhere to a one-size-fits-all methodology. Instead, they are highly responsive to user needs and continuously adapt—the main reason why teams require a well-defined plan to improve the quality of the system at each phase of the life cycle.
Software vs. System Development Life Cycle
Oftentimes, the system development life cycle is confused with the software development life cycle. Although they share many similarities, the development of systems is more robust and complex in terms of its overall framework.
Given the method’s complexity, there are various methodologies out there to help you manage and control the entire process. These methodologies may be agile, waterfall, iterative, and so on.
Phases of the SDLC
In the first phase, the team determines whether or not there’s a need for a new system to reach the strategic objectives of a business. This is a feasibility study or preliminary plan for the company to acquire any resources necessary to improve a service or build on specific infrastructure.
The main purpose of this step is to identify the scope of the problem and come up with different solutions. Some of the things to consider here include costs, benefits, time, resources, and so on. This is the most crucial step because it sets the tone for the project’s overall success. Thorough research is required before moving forward to the next stage.
The second SDLC phase is where teams will work on the root of their problem or need for a change. In case there’s a problem to solve, possible solutions are submitted and analyzed to figure out the best fit for the project’s ultimate goal or goals. It’s where teams consider the functional requirements of the solution.
Systems analysis is key in figuring out what a business's needs are. It also helps point out how those needs can be met, who will be responsible for certain parts of the project, and the timeline that should be expected.
Phase 3 defines the necessary specifications, operations, and features that will satisfy all functional requirements of the proposed system. It’s where end users can discuss and identify their specific business information needs for the application. During this phase, users will consider the important components, networking capabilities, and procedures to accomplish the project’s primary objectives.
Real work officially begins in the fourth phase. This is the part when a network engineer, developer, and/or programmer are brought on to conduct major work on the system. This includes ensuring the system process is organized properly through a flow chart. Many consider this the most robust SDLC stage as all the labor-intensive tasks are accomplished here. Phase 4 represents the real beginning of software production and hardware installation (if necessary).
5. Testing & Integration
In the fifth phase, systems integration and testing are carried out by Quality Assurance (QA) professionals. They will be responsible for determining if the proposed design reaches the initial business goals set by the company. It’s possible for testing to be repeated, specifically to check for bugs, interoperability, and errors.
Testing will be conducted until the end-user finds it acceptable according to standards. Another part of this stage is validation and verification—and both are done to help ensure the successful completion of the project.
Phase 6 begins when a huge part of the program code is completed. This phase also involves the actual installation of the newly-developed application. The project is put into production by moving all components and data from the old system and putting them in a new one through a direct cutover.
This move is considered complex and uncertain but the risk is minimized substantially as the cutover often takes place during off-peak hours. Both end-users and system analysts should see a refined project with all necessary changes implemented at this time.
In the seventh and final phase, end users can fine-tune the completed system as necessary if they want to improve performance. Through maintenance efforts, the team can add new capabilities and features and meet new requirements set by the client.
This stage ensures the system stays usable and relevant by regularly replacing outdated hardware, inspecting performance, improving software, and implementing new updates so all standards are met. This also equips the system with the latest technologies to face new and stronger cybersecurity threats.
Following the system development life cycle is crucial each time a new project or phase of a software project is released. Doing so gives teams a systematic approach that in turn enables them to come up with new solutions to existing issues in a standardized and controlled manner.
How the SDLC will cover and satisfy overall requirements should be determined before embarking on a new project so you can achieve the best results. Once that step is done, you can select the right SDLC methodology or a hybrid of models that is perfectly suited to your main project requirements and expected end result.