SDLC Models: Approach Development the Way That Works for You

More than half of all IT projects fail. Misinterpreting business objectives, ignoring the customer and incorrectly prioritizing tasks are the most common reasons for software project failure. Interestingly, all these reasons have a common root: the wrong software development approach.

In this article, you’ll learn about the key software development life cycle models (SDLCs) and real-life use cases. Vadim Kulaga, Software Engineering Manager and Delivery Manager at EPAM, explains how to approach projects and what results this brings.

The main software development life cycle models

A software development life cycle (SDLC) model is a sequence of actions you must complete to build a solution. Simply put, it’s a way to deliver a software product.

And that’s where the hard part begins. The problem is that many SDLC models are used for different types of projects. How do you know which is the right one for your project?

To answer this question, we’ve listed some of the most popular SDLC models, their use cases, advantages and disadvantages.

The waterfall model

This is a linear and sequential software development model where project phases follow one another and include:

• Discovery. The development team collects project requirements and includes them in the Software Requirements Specifications (SRSs) document.
• Design. They analyze all the requirements and roll out a system prototype.
• Coding. Once project stakeholders accept the prototype, the coding phase begins.
• Testing. The QA team runs each unit through various testing scenarios and integrates them into the system. When all components are in place, they test the entire system.
• Deployment. The product is delivered to the customer, as bug-free as possible.
• Maintenance. The development team monitors the project and makes updates if necessary. 

Waterfall is a highly organized model; you cannot skip phases, change their order or alter requirements once the project is in full swing. 

Use cases

The waterfall model is a great option if all these conditions are true: 

• The project is short and zero-risk
• Requirements are fixed
• Technologies are stable
• All the necessary resources are available 

Just a decade ago, many companies used the waterfall model to develop enterprise software, including CRM, supply chain management and point-of-sale systems. But today, the model fails to address the rapidly changing tech needs, so companies are increasingly turning to more recently developed approaches.

The V-shaped SDLC model

Basically, the V-shaped model is a QA-driven version of the waterfall, with a testing procedure that corresponds to each phase. 

For example, when the development team gathers project requirements, the QA experts write acceptance tests based on these required scenarios. Similarly, system testing scenarios are developed during the system design stage—and so on down the left side of the “V.” After the coding stage, the QA team validates the product against the pre-written tests. This is represented by the right side of the “V.” 

Use cases 

The V-shaped model can be extremely useful in cases when bugs might be fatal and in projects where precision is crucial. 

For example, this model is a go-to for regulation-based solutions, such as tax filing applications, and is often used in healthcare.  

Agile software development models 

Contrary to popular belief, Agile is neither a framework nor a methodology. It’s a philosophy with a set of principles focused on accelerating the software development process, ensuring 100% customer satisfaction and delivering high-quality solutions in a fast-changing environment. In fact, there are 12 principles of Agile development based on the following values: 

• Individuals and interactions over processes and tools 
• Working software over comprehensive documentation 
• Customer collaboration over contract negotiation 
• Responding to change over following a plan 

The Agile values have given rise to more than 50 methodologies, with Scrum being the most popular one. 

EPAM experience: Agile development 

Let’s face it: no single SDLC models is a “magic pill.” You can’t just pick a methodology that seems to suit your project needs and follow it blindly. At best, your development process will not improve. At worst, you’ll put your entire project at risk. 

For example, at EPAM—with projects of huge magnitude and complexity—it might seem challenging to satisfy the ever-changing user and stakeholder needs. However, we usually roll out releases daily (!) while keeping our solutions safe, reliable and performing highly. 

How did we manage to achieve a workflow like this? Here are some insights: 

• Don’t lock your project inside one methodology. We combine several SDLC approaches based on the current needs and the process type.  
• Use tech to gather user feedback. Collecting user feedback regularly and using it to make improvements is necessary for a project that involves many user interactions. We constantly review our feedback messages to gain a better understanding of what kind of obstacles people experience when using our product. 
• Foster collaboration. Scrum planning events, daily scrums and other meetings are a part of our routine. We also involve our technical leads in business analysis meetings where the early prototype is demonstrated and business features are discussed.  
• Share your knowledge. We have a knowledge base accessible to everyone involved in the project which is regularly updated as the project evolves. 
• Take care of your remote project contributors. Face-to-face communication is the cornerstone of any Agile project. Given this, never neglect your remote employees. Make sure they understand the project goals and are engaged in all the processes. 

Conclusion 

Software product success depends largely on choosing a suitable SDLC model and implementing it in the right way. Still, every project is unique, and there’s no one-size-fits-all approach to process modeling in software engineering. Don’t forget that every methodology is limited in a certain way, too.  

If you are planning on a career change, check out our vacancies at https://www.epam.com/careers