SDLC Models: How to Choose the Best

Software Development Lifecycle

An adage says that failing to plan is planning to fail. This is what SDLC models are all about, guiding software developers through software development projects.

But, what is SDLC models and how do you choose which one to use for your projects.

What is SDLC?

Software development lifecycle (SDLC) is the process used to design, develop and test software. Software development is divided into different phases whereby each phase defines the tasks to be carried out. This helps to run a software development project from start to end efficiently.  

If a developer fails to have a plan, the result would be a project that does not meet customer expectations, fails to reach timely completion, and may not be within the customer budget.

SDLC is important as it also helps to point out errors and avoid carrying them to later stages of a project – this would be costly to correct.

This starting point or guide for software development involves several phases. However different models have different numbers of phases. The unique steps in each model are meant to ensure it achieves a certain goal. Nevertheless, the basic stages of the SDLC model include requirement analysis, design, development, testing, and deployment.

SDLC Models

Although there are numerous SDLC models, the common ones include:

  1. Waterfall model –the traditional waterfall model consists of 7 phases. It is a sequential model where each phase has to be completed before moving to the next. It is simple to understand and use as is but also takes a long time to have a working system.
    Although this model is easy to manage it is not suitable for long and ongoing projects as it does not accommodate changes made in the middle of the project. Therefore, it works well for small projects whose requirements are clear, fixed, and well documented.
  2. Iterative model – a small set of software requirements are used to start a project. More specifications are used to evolve the software and each time a new version is created. This means that each phase has a working version, suitable when all the system requirements are well defined and understood. Good to use when the development team is trying new technology. 
  3. Spiral model – combines the idea of the waterfall model and the iterative model. It contains four phases, that is, identification, design, build, and evaluation, and Risk analysis.
    Suitable for large projects and enables the development of software and the incorporation of user feedback in the project.
  4. V-model – also known as the validation and verification model. In this linear model, each stage includes a testing activity. Like the waterfall, it is rigid as no additional changes can be done to the initial requirements. It is the most expensive and time-consuming. Suitable for software systems that cannot tolerate failures such as medical software and aviation systems.  
  5. Big Bang model – a high-risk model and works best for small projects. In this model, a project starts with no thorough requirements defined. Unlike others, this model follows no specific process.
  6.  Agile Model – this model has become a driving force behind software development.  The model separates a product into cycles making it easy to deliver a working product quickly. A succession of releases is produced with each being a new version that incorporates feedback from the previous release. Heavily relies on customer interaction. The Agile methodology also has frameworks such as Scrum, Kanban, lean among others.  

Which SDLC Model is Best for Your Project?

This entirely depends on the kind of project at hand. First, you need to understand the project requirements properly before selecting a suitable model. Although all the SDLC models operate differently, they have a common purpose and this is to help increase the efficiency of software development.

Keep in mind that the type of model you choose will determine the quality of a project, its timely completion, as well as ability to meet customer expectations and budget.  

Sign up for our Newsletter