Software Development Life Cycle (SDLC)

What is SDLC – Software Development Life Cycle? 

Software Development Life Cycle (SDLC) refers to a framework that defines the various steps involved in software product development in each stage. It covers detailed plans for all stages – building, deploying, and maintaining the software. 

Broadly, SDLC includes phases – requirement gathering, analysis, design, implementation or coding, testing, deployment, and maintenance. 

Adopting a structured SDLC approach is crucial. It relates to breaking down large and complex software projects into smaller modules and implementing them one by one. This ensures simple execution and timely delivery of the project.

SDLC phases

Requirements gathering & analysis

This phase deals with understanding and collecting the business requirements from the client to develop a product that meets their expectations. It involves a series of meetings between the business analyst and the project manager to understand the nitty-gritty of the project – the client’s needs, who the end-user is, what changes are required in the existing product, if any, and such. It is ensured that all requirements are clearly understood and there’s no scope for any ambiguity.

The stage also includes an analysis of the requirements, and in case of any clarification, further clarifications are made with the customer. Once everything is ready, the Software Requirements Specification (SRS) document is created, which is thoroughly understood by the development team. This document serves as a future reference for the customer.

Design

This phase involves a detailed study of the requirements in the SRS document and based on the technical feasibility, the relevant software architecture that must be used to develop the software is determined. At this stage, a design document is created for developers to work on.

Implementation / Coding

In this phase, the developers or programmers work on the design document created earlier to translate the statements to source code. It is ensured that all software components are completed in this stage.

Testing

In the testing phase, all software modules developed are tested rigorously by testers who identify any defects in the execution. Testers use the Software Requirements Specification document to ensure the code runs as per the customer’s business requirements. 

If any inconsistencies are found, they are handed over to developers who fix them. Unit testing, regression testing, and various rounds of testing are carried out to ensure the product is completely error-free.

Deployment

This phase involves deploying the tested software in the live or production environment. Usually, it is preceded by User-acceptance testing (UAT). During UAT, a production-like system is provided to the customers who test it along with developers. Once the customer is satisfied, they give a sign-off, and developers deploy the system to production.

Maintenance

This stage involves monitoring and maintaining the software developed after it is deployed in the production environment. Any errors or issues that arise in the future are handled and fixed by the developers.

SDLC Models

Waterfall

The methodology adopts the simple SDLC approach of – requirement gathering, analysis, design, implementation, testing, and deployment. The output of the previous phase serves as the input for the subsequent phase. The phases are implemented sequentially, and only the completion of one phase can lead to the start of the next.

Advantages

• Easiest mode of project management as each phase is done step-by-step
• No complexity as deliverables are well-defined and projects are easily manageable

Disadvantages

• Time-consuming and not suitable for short-term projects.
• The new phase can begin only when an ongoing phase is completed
• Difficult to incorporate new requirements as that would lead to higher costs.

Agile

Agile is an SDLC model that breaks the product into smaller incremental builds rather than implementing it in one go. Agile builds keep adding new features, and each increment is termed as a sprint. Each sprint occurs for 2-4 weeks. 

The product owner decides the requirements with the stakeholders, and based on their guidance, the product is delivered to customers. Customer feedback is collected after each sprint, and new features are included in the next sprint for improvement.

Advantages

• Offers greater flexibility
• New features are included easily
• Customer feedback is given priority, and the focus is on continuous improvement

Disadvantages

• Lack of clarity on requirements would lead to project failure
• Requires highly skilled and professional resources

DevOps

DevOps is the SDLC model wherein the two functions, development and operations, work together throughout the SDLC from development to deployment to operations. It is an approach involving continuous integration and continuous delivery.

Advantages

• Emphasizes collaboration and communication
• Rapid processes due to continuous integration and continuous delivery
• Focuses on automation of software delivery
• Performs incremental yet frequent updates 

Disadvantages

• Increased complexity of IT infrastructure
• Requires highly experienced engineers and professionals
• Lack of standardization
• Increased costs

Best practices

Leading practices to follow in SDLC include deploying code review teams, continuously testing the code, ensuring complete documentation, following the scrum practices, tracking engineering metrics, and having well-defined, clear workflows. Other practices include opting for CI/CD, collaborative learning, and more.

Challenges 

• Businesses are growing in complexity, and so more complex software needs to be implemented to meet their requirements. This makes constant collaboration and communication between developers, project managers, and business analysts more frequent.
• Depending on the feasibility and complexity of the business needs, it is difficult to assess the correct timelines and effort needed for each phase of the SDLC.
• Timelines are stringent; however, quality and security aspects cannot be compromised.
• Customer requirements keep changing during the SDLC, and the growth of new, complex technologies creates added challenges to incorporate.
• Emerging technologies like AI, blockchains, etc., call for expert resources, and these are abstract thus making it difficult to fix the project duration, plan the phases, and more.

Kubernetes and SDLC

Kubernetes development involves automating deployment, scaling, and maintenance of containerized applications. It works by grouping containers that constitute an application in a logical manner for better management. 

By embedding the SDLC model (waterfall, agile, or DevOps) into the Kubernetes development and maintenance, it can become more structured and efficient.

Orchestration platforms like Kubernetes allow easier and faster deployment of applications. One way is they increase scalability, which improves the software development life cycle. 

An example is to redesign the legacy architecture into microservices by which developers can add or modify resources to the containers in the cluster. This improves the SDLC – whether the model is waterfall, agile, or DevOps, the changes take place faster, and the time spent on a phase is reduced.

Summary

SDLC approaches focus on reducing the cycle time, enhancing collaboration and communication, increasing flexibility in making updates and improving overall process efficiency. Structured SDLC methodology ensures that processes are carried out sequentially, and appropriate timelines are set. 
With Kubernetes deployment, the various phases of the software development life cycle can be automated easily, ensuring timely and quality delivery of software projects.