Software Development Life Cycle Methodologies

Software Development Life Cycle (SDLC) is the process followed for software development, encompassing its organization, planning, delivery, and more.

What is SDLC?

It is a process followed for a software project within a company. It consists of a detailed plan that describes how to develop, maintain, change, or enhance specific parts of the software. The cycle defines a methodology to improve software quality and the overall development process.

1. Planning and Requirements Analysis

Analysis of business rules is one of the most fundamental stages in SDLC. It is performed by senior team members with inputs from clients, sales departments, market research, and industry experts. This information is used to plan the project's basic approach and conduct product feasibility studies in economic, operational, and technical areas.

Planning for quality assurance requirements and identifying project-associated risks is also done in the planning stage. The result of feasibility studies is to define the various technical approaches that can be followed to successfully implement the project while assuming minimal risks.

2. Defining Business Rules

Once requirements analysis is complete, the next step is to clearly define and document all business rules and acceptance criteria, obtaining approval from clients and market analysts. This is done through a Software Requirement Specification (SRS) that consists of the design of all product requirements and their development throughout the project's life cycle.

3. Project Architecture Design

The SRS serves as a reference for product architects to develop the best possible architecture. Based on the requirements specified in the SRS, typically more than one design approach is proposed and documented in a Design Document Specification (DDS).

This DDS is reviewed by all major stakeholders, and based on various parameters such as risk analysis, product robustness, design modularity, budget, and time constraints, the best approach for the product is chosen.

A clear design approach defines all the architecture modules of the product along with their communication and data flow representation with external modules (if any). The internal design of all modules of the proposed architecture should be clearly defined with maximum detail in the DDS.

4. Product Construction and Development

Here, the actual development begins, and the product is built. The programming code is generated according to the DDS in this stage. If the design is applied in a detailed and organized manner, the code generation can be completed without major difficulties.

Developers should be familiar with the code guidelines defined by their organization, as well as the relevant tools. The choice of programming language to be used is determined according to the software to be developed.

5. Product Testing

This stage is generally a subset of all stages in modern SDLC models. However, this stage specifically focuses on product testing, where defects are located, reported, cataloged, corrected, and validated until the product meets the highest quality standards.

6. Market Implementation and Maintenance

Once the product has been tested and is ready to be implemented, it is formally released to the market. Sometimes, product implementation occurs in stages, according to the organization's business strategy. The product may be first released in a limited segment and tested in the actual business environment (User Acceptance Testing - UAT).

Then, based on feedback, the product may be released as is or with improvements suggested by the target market. Once released to the market, its maintenance is focused on the existing user base.

SDLC Models

Several defined and architected models are followed during the development process. These models are also called Software Development Process Models. Each process model follows a unique set of steps to ensure success in development processes.

The most popular SDLC models include:

• Waterfall
• Iterative
• Spiral
• V-Model
• Big Bang

What Is Quality Assurance in SDLC?

Quality Assurance (QA) plays a fundamental role in the process to be implemented in the development cycle.

Its primary function is to ensure that the software meets business rules, is free of bugs, and functions perfectly under different circumstances.

For the current market reality, where a product will be available in various modes, it is critical that it is developed without defects. This is where QA comes in.

QA in IT is integrated into all stages of development and is used even after the release stage.

QA experts create and implement various strategies for software quality improvement, applying various types of tests to ensure proper functionality. This stage is called Quality Control (QC).

Which Professionals Are Part of the QA Team?

Depending on the company, the main roles are:

• QA Analyst: Close to the business analyst, they collect all project information, assess risks and weaknesses, and create documentation to describe future development aspects that QA Engineers need to pay attention to.
• QA Lead: The team's leadership is the person who controls the entire team of experts. In addition, the lead manages tests, creates test plans, processes information received from analysts, observes all deadlines to ensure timely testing.
• QA Engineer: This specialist applies tests and does everything to improve the overall quality of the software, ensuring that it complies with business rules.

Responsibilities of a QA Team in IT

The scope of QA tasks should be quite broad. The Quality Assurance team once again proves its importance in SDLC.

• Test Planning: Analysts plan the testing process, with their goals to achieve and which approaches to use.
• Initial Testing: QA engineers conduct initial testing to identify bugs during the first development phase to expedite it.
• Test Execution: QA engineers apply manual or automated tests of different types according to the software's peculiarities.
• Defect Analysis: It is necessary to analyze all defects and identify the reason for their occurrence.
• Reporting: Experts use bug tracking systems and create reports for developers with descriptions of the bugs and defects to be fixed.
• Collaboration: The QA team collaborates with business analysts, project managers, developers, and clients to achieve the highest possible quality for a software product.
• Test Summary and Report Creation: When software is tested, QA engineers need to create reports summarizing the quality level of the software.

The Role of QA in Project Development

Quality Assurance in the software development life cycle plays a crucial role in all stages, such as:

• Requirements Analysis: In IT, the QA team collaborates with business analysts to develop a feasibility study of business rules, analyze potential risks, create a test plan, and build a quality assurance approach (each project requires an individual approach due to its specificities), including which tests to use, etc.
• Design: A review of the design is required, checking its stability, ensuring that its architecture meets all requirements. In addition, QA experts produce data flow diagrams in conjunction with UI/UX designers and document them. Finally, QA engineers test the design after completion to mimic end-user behavior.
• Development: QA in software development can be applied once the software is developed, or according to the Test-Driven Development (TDD) approach, which defines testing during the development process after each iteration.
• Post-Launch QA: Once launched, developers must maintain the product. The QA team then creates user guides and product manuals for delivery to end-users. They also create test documentation to ensure that all bugs have been identified and corrected.

The Importance of the Quality Assurance Process

• Saves Resources and Preserves Reputation: The latter being one of the most important. For example, if you develop trading software and have not tested it correctly, users would lose money, and even compensating for their losses would be impossible to save the reputation of your product. Therefore, quality assurance helps detect bugs before users encounter them.
• Prevents Emergencies: Imagine that you commission the development of internal use software, and your employees will use it for better communication with clients. Even a small bug can lead to severe failures such as data loss and communication breakdowns. Recovering this information without additional expenses will be more complex.
• Increases Customer Loyalty: Bug-free software means that customers do not face problems when using your application. Furthermore, if you respond to customer complaints and rectify issues promptly, your clientele will see that you respect them and aspire to the highest levels of quality. As a result, your customer base is retained, leading to additional profit.
• Impacts Employee Productivity: Employees can work better and more efficiently when obstacles such as software bugs do not get in their way. Employees do not waste time trying to figure out the reasons behind software failures and other challenges to continue their work.
• Makes Software Safer: Finally, quality assurance contributes to a more secure application by eliminating vulnerabilities and defects, preventing malicious attacks. The cost of QA services is incomparable to potential financial losses that a business can suffer due to a lack of reliable protection.