The Software Development Lifecycle is the foundation of software creation. Because it ensures that all processes for creating software are completed step by step. Engineers and developers use SDLC models as a planning guide at each stage of software creation to ensure cost-effectiveness and timely completion of the project. Because nothing happens spontaneously when creating software, a random path cannot be followed.

Software development should involve a well-planned process. Otherwise, long delays can occur and lead to erroneous results. An effective software development process is an integral part of the software development lifecycle and ensures fast, quality delivery.

It is important to have knowledge about life cycles and processes before embarking on software projects. So what is SDLC (Software Development Life Cycle)? what does it do? How do processes proceed? Let's take a look at what there is to know about SDLC together.

What is SDLC?

The Software Development Lifecycle (SDLC) model is a conceptual framework that describes all activities in a software development project, from planning to maintenance. This process is linked to different models, each with a variety of tasks and activities. In other words, SDLC or Software Development Lifecycle is the framework methodology for developing high-quality, effective and efficient software and implementing it as soon as possible. This term is also known as the software development process model. The SDLC framework, on the other hand, contains predefined processes, stages, and each stage of the SDLC provides the necessary products for the next stage of the life cycle.

Software development is a burdensome activity that requires proper definition of requirements, their implementation and software implementation. But the activities do not end there, after the distribution of the software, proper maintenance must also be carried out in a timely manner.

Why is the Software Development Lifecycle Important?

Most software is created by engineers and programmers who work on it in teams. In this process, each employee must follow a consistent procedure while contributing with their expertise to successfully complete projects on time and within budget. SDLC's process and consistency are essential to delivering software on time and successfully.

SDLC outlines each project for success and keeps all interested parties on the same page, which supports both low-cost quality software and overall cost reduction efforts. SDLC makes software development easy. This approach adds great value to the development process. Other advantages of SDLC include:

• It supports you to bring the software to market faster: While development and supply time can be significantly reduced, better quality software reduces the likelihood of errors or inconsistencies in production processes.
• The SDLC model provides management control: Project managers of both small and large projects can use the SDLC framework to track the progress of a specific task or initiative using visualization features and tracking graphs.
• Helps unify software lifecycle development teams: The Software Lifecycle helps bring all members of a development team together under one roof so that everyone can understand what to expect and plan effectively for it.
• Eliminates existing silos between teams: SDLC stages help break down silos between teams by promoting communication and collaboration among its members.
• It ensures that the roles and responsibilities are clear: Each SDLC stage clearly states the purpose. Therefore, each team member knows his own position in it.

Software Development Lifecycle SDLC Processes

SDLC works by assessing existing customer system deficiencies and determining the requirements of the new system by following the lifecycle stages. Even after the software is deployed to the client environment, user problems and additional improvements that arise can become a requirement for the next cycle. The software development lifecycle is a model for continuous improvement and consists of specific stages. This entire Software Development Lifecycle can be broken down into six main phases:

1st Mandatory Stage

It is the first stage of the software development lifecycle and involves the collection of requirements for the software. The collection and analysis of requirements is the most critical stage of SDLC. In this phase, the business analyst collects the needs determined according to the business processes from the client and other stakeholders and includes them in the Business Requirements Specification (BSR) document. The most common steps in the SDLC requirements phase are:

• Understanding customer requirements
• Creating process flowcharts

2. Analysis - Planning Phase

The next step in the SDLC Software Development Lifecycle process is to identify and document product requirements and ensure that they are approved by the customer and other stakeholders. This document is known as the Software Requirements Specification (SRS) document. Software Requirements Specifications (SRS) cover all product requirements that need to be designed and developed throughout the software development lifecycle. The most common steps in the analysis and planning phase are:

• Drawing up a project plan
• Evaluation and identification of resources
• Feasibility assessment

3. Design and Prototype Phase

In the third phase, the team brings together all the information collected so far while designing the software architecture. They can offer multiple designs so that they can choose the one they think is best for the job. This phase focuses on software architecture, prototyping, and user experience design. The design phase in the software development lifecycle involves two functional steps:

• High-Level Design (HLD) provides the architecture of the software product. Software architects and senior developers develop this design.
• Low Level Design (LLD) reveals the workings and workings of each function and part in the product.

4. Development and Implementation phase

The Development and Deployment phase is the stage where software developers begin to write the code for the product, the operations team will install the physical hardware for the servers, and the designers will program the user interface. The coding stage is the process of transforming the design into a working software product. Two important steps in this phase are:

• Establishment of IT infrastructure
• Creating a code base for software

5. Testing phase

During the development and commissioning phase, servers, databases and applications are installed. Now the software is transferred to the testing team, which is ready in the testing phase. The testing and KG (Quality Assurance) team verifies that all requirements are met, ensuring that all functions work as expected and identify possible errors and report them to the fault monitoring system. The bugs are then assigned to the developers and corrected. This process is also known as the Error Lifecycle. The two main activities at this stage are:

• Code and test scenarios
• Execution of test scenarios

6. Application and maintenance phase

In the implementation phase, the operations team eventually focuses on phasing or development environment systems and makes the software ready for production. The application team installs new hardware and servers and makes sure everything is scalable for production. This, in turn, allows setting up connections and databases for real-time users and synchronization with development teams, version managers. The application, which will go live for real users after the production unit is set up, can be downloaded by millions of users.

The maintenance team, on the other hand, supports the application in all conditions and updates and improves the software to fit real customer scenarios.

Software Development Lifecycle Models

Software development methods vary depending on the type of project. While all models follow similar steps in theory, each is applied differently when it goes into practice. Here are the commonly used SDLV Models.

Waterfall Model

The waterfall model is the oldest and linear-ordered approach to software development and is a linear sequential approach to software development. In this model, sequential progression seems to flow continuously downward, like a real waterfall. This model is easy to understand and use. Each stage must be completed in full before proceeding to the next stage in the waterfall model. Proceed to the final stage of testing.

V Modell

The V-Shaped Model or V-Model is an extension of the waterfall model. In this SDLC model, software development occurs sequentially in a V-shape. It is a validation and validation approach. Each stage of the V model is completed before the next stage begins. Testing of the product in V-Model is carried out in parallel with the relevant development stages. In the V-shaped model, each stage in the development lifecycle is directly correlated with the different testing stages.

Prototype Model

The prototype model is the running model of software with limited functionality. In this model, the developers create a working prototype of the real product with the most useful features provided by the customer.

When the prototype is ready, it is delivered to the customer for evaluation. Following customer feedback, new deadlines and processes are set by developers. Reduces multiple iterations compared to other models.

Repeative/Incremental model

The iterative or incremental lifecycle model starts with the simple implementation of a small set of software requirements and gradually improves the software until the entire system is ready to deploy/deploy. The iterative model does not start with customer feedback. Instead, software development starts with a subset of the requirement and is gradually improved across multiple iterations before developing the final product.

Spiral Model

The spiral model is a combination of the repeating pattern and the waterfall model. It allows the creation of software, taking into account risks that are not calculated in other models. The goal is to prototype the software with a strong emphasis on risk analysis. The spiral model allows gradual release and improvement of the product with each iteration.

The Agile Model

Agile is actually a software development methodology with a philosophy of deploying an application much more organized and quickly. Simply put, it is an agile, fast development and implementation chain. The agile model divides the application into small pieces of code following the microservices model to adapt to changing business requirements and helps build software incrementally using short iterations.

The Software Development Lifecycle, which also has different models such as Big Bang Model WIP, DevOps Model, establishes the basic steps you can follow in software development processes and allows you to get clearer results. Thanks to the Komtaş ecosystem, you can benefit from services during the software development phases and get in touch immediately for data or AI-powered solutions.

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