In short
The challenge: For IT leaders to select and implement an SDLC model that truly fits their organisation’s unique environment. While SDLC offers a structured approach to software development, no single model suits every team or project. Many organisations struggle by rigidly applying one methodology or chasing trends, leading to misalignment, inefficiencies, and technical debt. The real difficulty is in evaluating which model best supports strategic goals, team dynamics, and long-term scalability.
The solution: Rather than defaulting to one method, selecting a model or a thoughtful combination that fits your unique environment is key to reducing risk, improving collaboration, and driving long-term success.
The outcome: The right SDLC model helps IT leaders deliver reliable, scalable, and on-time software by aligning development practices with your team’s working style, business goals, and project complexity.
Delivering software that is reliable, scalable, and on-time is non-negotiable for your business. Yet, for Heads of IT departments, one of the most persistent challenges is choosing the right structure to manage software development across diverse teams, legacy systems, and evolving business needs.
That’s where the strategic tool of the Software Development Life Cycle (SDLC) comes in.
What is SDLC?
The SDLC is a structured framework that defines the stages of software development from initial planning and requirements gathering, to design, development, testing, deployment, and maintenance. At its core, SDLC provides a systematic way to build software that aligns with business objectives and delivers value at every phase while minimising risks.
While the concept itself isn’t new, how it's implemented can make or break a project. That’s because no single SDLC model fits every team, project type, or organisational structure. Each have their advantages and trade-offs. For IT leaders, the key question isn’t just “Which SDLC model is best?” but rather, “Which model is the best fit for our unique environment?”
Why SDLC matters (especially to IT leaders)
Choosing the right SDLC model affects more than just your developers’ workflows. It influences how your teams collaborate, how quickly you can adapt to change, and how confidently you can meet business objectives. A well-suited model helps your department maintain control over timelines, budgets, and resource allocation while ensuring the final product meets both user and stakeholder expectations.
Yet many organisations still fall into the trap of either rigidly sticking to one model or trying to force-fit every project into the latest trendy methodology. The result? Bottlenecks, misalignment, and technical debt that could have been avoided with a more thoughtful approach.
As the head of an IT department, your role is to ensure the process of development supports strategic growth, operational efficiency, and long-term scalability. That’s why understanding the strengths and limitations of each SDLC model is essential.
In this blog, we’ll walk through six effective SDLC models, exploring how they work, what types of projects they’re best suited for, and where their pitfalls lie. Rather than presenting a “one-size-fits-all” solution, we’ll help you evaluate which model (or combination of models) aligns best with your team’s culture, your technology stack, and your organisational goals.
What are the 6 main SDLC models?
A number of different SDLC models are used today to guide companies through their project-based work.
Here are the key pros and cons of six of the most common SDLC models for project management and leading campaigns.
1) Agile Model
The Agile model is a flexible, iterative approach to software development that thrives on collaboration, customer feedback, and rapid delivery. Instead of following a linear path, Agile breaks projects into smaller cycles called iterations or sprints. Each sprint delivers a working product increment that can be tested, reviewed, and refined which makes it easier to adapt to change and align the final product with user needs.
For IT leaders, Agile offers a way to reduce risk, foster transparency, and build stronger cross-functional teams. But like any approach, it has its trade-offs, especially when communication or direction is unclear.
Pros:
Faster time to value - working versions of the product are delivered early and often.
Customer collaboration - regular feedback ensures the end product aligns with real needs.
Flexibility - agile allows for quick changes based on evolving requirements or priorities.
Transparency - ongoing updates and reviews help stakeholders stay aligned and informed
Team empowerment - developers and testers are involved throughout, encouraging ownership and accountability.
Cons:
Risk of misdirection - without clear input from stakeholders, teams may iterate in the wrong direction.
Resource intensity - continuous collaboration and frequent changes can strain time and personnel.
Less predictability - timelines and budgets can be harder to estimate upfront.
Requires cultural alignment: Agile demands a mindset shift from traditional models, which can be challenging for some teams or organisations.
Is SDLC waterfall or Agile?
This is a question that often pops up, and people get confused as to how the models are classified within SDLC. To be clear, SDLC is a framework that can support both Waterfall and Agile methodologies, it’s not limited to one. As we know from above, Agile is iterative and flexible. You will see in the Waterfall section below that model follows a linear, sequential approach. Both are SDLC models used depending on the project's needs and environment.
2) Waterfall Model
The Waterfall model is one of the most traditional and linear approaches to software development. It follows a step-by-step process whereby you complete one phase fully before moving to the next. For IT leaders managing well-defined projects with stable requirements, this can offer a sense of control, predictability, and clarity.
Each phase (requirements, design, implementation, verification, and maintenance) builds directly on the one before it. This structure makes it easier to manage timelines, resource allocation, and stakeholder expectations, especially in environments that value documentation and upfront planning.
However, the Waterfall model can be less forgiving when it comes to change. Once a phase is complete, going back to make revisions can be costly or impractical. This rigidity can become a challenge in projects where adaptability or ongoing feedback is essential.
Pros:
Structured and straightforward - clear phases make it easier to manage and track progress.
Good for fixed-scope projects - works well when requirements are unlikely to change.
Predictable timelines and budgets - easy to estimate time, resources, and costs up front.
Strong documentation - each stage produces detailed records, which can support audits and future maintenance.
Cons:
Inflexible - difficult to make changes once a phase is completed.
Delayed testing and feedback - issues may go unnoticed until later stages, making them harder (and more expensive) to fix.
Risk of early bottlenecks - delays in early phases can cascade and affect the whole project timeline.
Less ideal for complex or evolving projects - not well-suited for environments where needs might shift or expand.
Related: 10 effective management techniques to boost employee performance
3) V-shaped Model
The V-Shaped model (also known as the Verification and Validation model) is an evolution of the traditional Waterfall approach, designed for teams that value structure but also want to strengthen the connection between development and testing. In this model, each development stage is mirrored by a corresponding testing phase, reinforcing quality and reducing the risk of defects slipping through the cracks.
Like Waterfall, the V-Shaped model follows a linear path as one phase must be completed before the next begins. For IT leaders overseeing high-assurance projects where precision is critical (such as healthcare, aerospace, or regulated environments), this model can provide the accountability and thoroughness needed to meet strict standards.
However, this rigor comes with trade-offs. The model assumes requirements are well understood from the start. If priorities shift or new insights emerge mid-project, adapting can be challenging.
Pros:
Built-in quality checks - every development stage has a corresponding validation step, leading to fewer surprises later.
Clear structure and documentation - helps ensure accountability and traceability throughout the lifecycle.
Strong alignment with compliance needs - ideal for regulated industries where verification and validation are mandatory.
Early test planning - test cases are defined early, which can reduce downstream testing risks.
Cons:
Inflexible to change - once phases are underway, going back to adjust requirements or design is difficult and costly.
High upfront planning effort - requires detailed documentation and defined requirements from the beginning.
Delayed feedback loops - usability or customer feedback may come too late in the process to influence design.
Not ideal for exploratory projects - works best when the solution space is already well-understood.
4) Iterative Model
The Iterative model embraces evolution and continuous refinement. Rather than trying to define every requirement up front, this approach starts with a baseline set of features and builds on them in cycles. Each iteration includes development, testing, and evaluation which allows teams to uncover and address new needs as they arise.
For IT leaders, this model offers a valuable balance: early delivery of functional software, with the flexibility to adapt based on ongoing feedback. It’s especially useful in complex projects where requirements are expected to shift or aren't fully known at the start.
However, this model’s repetitive nature, while a strength, can also become a challenge. Without clear boundaries or disciplined oversight, repeated iterations can stretch resources and timelines more than anticipated.
Pros:
Early product visibility – a working version is available early in the development cycle, which builds trust and allows for quicker feedback.
Flexible and adaptive - new requirements can be integrated as they emerge, making this model ideal for evolving projects.
Lower risk of failure - issues are identified and addressed in smaller, manageable cycles.
Continuous improvement - each iteration sharpens the product closer to user needs and expectations.
Cons:
Resource-intensive - repeated development and testing cycles can strain team capacity and budgets.
Planning complexity - managing iterations, especially across multiple teams, requires strong coordination.
Scope creep risk - flexibility can lead to uncontrolled changes if not carefully managed.
Delayed final delivery - while early versions are functional, the full system may take longer to complete due to ongoing refinements.
5) Spiral Model
The Spiral model is one of the most adaptable SDLC approaches, combining iterative development with an emphasis on risk management. Projects move through a repeating cycle of four phases: planning, risk analysis, engineering, and evaluation. This process allows for continuous refinement and early stakeholder involvement.
For IT leaders managing large, high-stakes, or highly customised systems, the Spiral model offers a powerful advantage whereby you don’t have to choose between structure and flexibility. It supports careful planning and documentation while also making space for frequent feedback and evolving requirements.
However, with great flexibility comes the need for strong governance. Without clear checkpoints or boundaries, a project can become trapped in endless cycles, adding cost, complexity, and confusion.
Pros:
Highly customisable - ideal for projects that require tailored solutions or are expected to change over time.
Built-in risk management - each cycle includes dedicated risk assessment, helping avoid costly surprises.
Early and continuous feedback - user input is incorporated early and often, improving alignment and satisfaction.
Scalable for complex projects - well-suited for large systems with multiple stakeholders or uncertain requirements.
Cons:
Risk of project drift - without clear scope control, iterations can become open-ended, delaying delivery.
Resource-heavy - requires skilled teams and strong oversight to manage the complexity of repeated cycles.
Challenging to manage - the model demands significant planning, documentation, and coordination.
Less suitable for smaller projects overhead may outweigh the benefits in low-risk or short-term initiatives.
6) Big Bang Model
The Big Bang model is unconventional and intentionally unstructured. With minimal planning and undefined requirements, development begins right away. Resources in this SDLC model are focused on building, rather than outlining or documenting. In some cases, even the client may not have a clear vision at the start.
This model is often used in experimental or low-risk environments, typically by solo developers or small teams working on short-term projects. For IT leaders, it can offer room for exploration and speed when flexibility is more important than predictability.
However, the Big Bang approach comes with significant risk especially in complex or high-stakes scenarios. Without a clear roadmap, teams can invest heavily in development only to realise late in the game that the end product doesn’t meet expectations.
Pros:
Fast startup - minimal planning allows teams to begin development immediately.
High flexibility - developers can explore and pivot freely without being constrained by formal processes.
Simplicity for small projects - works well for prototypes, proofs of concept, or personal tools where formal SDLC processes aren’t necessary.
Cons:
High risk of misalignment - lack of defined requirements increases the chance of delivering the wrong solution.
No clear structure - without milestones or documentation, tracking progress or managing scope becomes difficult.
Not scalable - this model doesn't support complex, multi-phase, or multi-stakeholder projects.
Potential for wasted effort - if expectations shift or were misunderstood from the beginning, much of the work may need to be redone.
Related: 6 time management techniques for time poor professionals
Is DevOps a SDLC model?
Another question that often comes up is where DevOps fits in the SDLC sphere. The short answer is it doesn’t.
No, DevOps is not an SDLC model. Rather, DevOps it’s a culture and set of practices that focuses on collaboration between development and operations teams to improve software delivery. While it can complement SDLC models like Agile, DevOps itself is more about continuous integration, automation, and faster release cycles than a structured development framework.
Which SDLC model is right for you?
There’s no one-size-fits-all approach to software development. Each SDLC model offers a different way to navigate the real-world challenges you’ll face from shifting requirements to tight deadlines, complex integrations, or compliance concerns.
Choosing the right model depend on how your team works, how much clarity you have at the start, and how much flexibility you’ll need along the way. It’s about finding the best fit for your people, your processes, and the kind of value you’re trying to deliver.
As an IT leader, your ability to align the methodology with your project’s unique parameters like timing, risk tolerance, stakeholder involvement, and technical scope can be the difference between friction and flow, between rework and resilience.
Frequently Asked Questions (FAQs)
What is SDLC?
The Software Development Life Cycle (SDLC) is a structured process that guides the creation of software from initial planning through to deployment and maintenance. It helps teams build reliable, high-quality software that aligns with business goals while managing risks and resources effectively.
What are the main phases of the SDLC?
The main phases of the SDLC include planning, requirements gathering, design, development, testing, deployment, and maintenance. Each phase plays a critical role in ensuring the software meets business goals, user needs, and quality standards.
What are the different SDLC models?
Agile Model
Waterfall Model
V-Shaped Model
Iterative Model
Spiral Model
Big Bang Model
What are the pros and cons (or advantages and disadvantages) of each SDLC model?
Agile Model
Pros:
Faster time to value
Customer collaboration
Flexibility
Transparency
Team empowerment
Cons:
Risk of misdirection
Resource intensity
Less predictability
Requires cultural alignment
Waterfall Model
Pros:
Structured and straightforward
Good for fixed-scope projects
Predictable timelines and budgets
Strong documentation
Cons:
Inflexible
Delayed testing and feedback
Risk of early bottlenecks
Less ideal for complex or evolving projects
V-Shaped Model
Pros:
Built-in quality checks
Clear structure and documentation
Strong alignment with compliance needs
Early test planning
Cons:
Inflexible to change
High upfront planning effort
Delayed feedback loops
Not ideal for exploratory projects
Iterative Model
Pros:
Early product visibility
Flexible and adaptive
Lower risk of failure
Continuous improvement
Cons:
Resource-intensive
Planning complexity
Scope creep risk
Delayed final delivery
Spiral Model
Pros:
Highly customisable
Built-in risk management
Early and continuous feedback
Scalable for complex projects
Cons:
Risk of project drift
Resource-heavy
Challenging to manage
Big Bang Model
Pros:
Fast startup
High flexibility
Simplicity for small projects
Cons:
High risk of misalignment
No clear structure
Not scalable
Potential for wasted effort
When should you use the Spiral model vs the Waterfall model?
Use the Spiral model when your project involves high risk, evolving requirements, or needs frequent refinement through iterative development and feedback. The Waterfall model is better suited for projects with clearly defined requirements and minimal expected changes, where a linear, structured approach is more efficient.
