How to Choose the Right SDLC Model For Your Project
The success of any software development project depends on several factors. One crucial aspect is selecting the right Software Development Life Cycle (SDLC) model. The SDLC model serves as a framework for the entire software development process. It guides the team from the initial planning stages to the final deployment and going live.
With numerous SDLC models available, it can be challenging to determine which one is most suitable for your project. In this article, we will explore the key factors to consider when choosing an SDLC model and provide insights to help you make an informed decision.
Common SDLC models
Several SDLC models exist, each following different processes and approaches. Here are some commonly used SDLC models:
Waterfall model
The Waterfall model is a traditional linear and sequential approach to software development. It consists of distinct phases, such as requirements gathering, design, development, testing, deployment, and maintenance. Each phase is completed before moving on to the next, making it a rigid and structured model.
A distinguishing feature of the Waterfall model is that it is a well-planned and detailed approach where the performers adhere to the plan.
Pros:
Resistance to performer replacement
Flexibility in the initial stages of work
Clarity in meeting deadlines and budget requirements
Cons:
A significant amount of documentation is required
The ability to see the result only at the end of the project
All requirements need to be determined in advance, but clients may not always be able to clearly articulate their needs
Best suitable for projects with clear deadlines and budgets (Fixed Price projects). In such projects, the client is confident in all the requirements and does not intend to make any changes during the development process.
Agile model
The Agile model emphasizes iterative and incremental development. It promotes collaboration, adaptability, and flexibility throughout the project. Agile methodologies, such as Scrum, Kanban, and Extreme Programming (XP), focus on delivering functional software increments in short iterations, accommodating changes in requirements and customer feedback.
A distinguishing feature of Agile development is the ability to make changes at every stage of the project.
Pros:
Decreased probability of project failure
Minimized risk of missing deadlines
Maximum team involvement
Cons:
Lack of clear project structure and plan
Constant interaction with the client is required
Excessive focus on details
Best suitable for projects with evolving requirements that require frequent feedback.
Spiral model
In the Spiral development model, the product life cycle is represented as a spiral and divided into phases. Each iteration in the spiral represents an increment, which results in ready-made functionality. The Spiral model includes risk analysis and assessment at every development phase. Thanks to a strong emphasis on risk management, the team can detect and mitigate potential issues early on.
A distinguishing feature of the Spiral model is special attention to identifying and eliminating project risks throughout the entire development process.
Pros:
Additional features or changes can be made later in the process
Cost estimation is simplified as prototyping is done in small increments
Development progresses quickly, with features being added systematically
Cons:
Risk of schedule or budget deviations
Best suited for large projects and requires expertise in risk assessment
Strict adherence to the spiral model protocol is necessary for smooth operation
Best suitable for projects developing a new line of products.
V-Shaped model
The V-Shaped model emphasizes testing at each stage. Testing activities are aligned with the corresponding development phase, ensuring comprehensive verification and validation. The V-Shaped model illustrates the progression from requirements gathering, design, and coding on the left side of the V, to the testing and verification activities on the right side of the V.
A distinguishing feature of the V-Shaped model is running quality assurance procedures at each stage of project implementation.
Pros:
Clear phasing of SDLC
Early detection of defects
Reduced rework
Cons:
Limited flexibility in accommodating changes or iterations
Increased risk of project delays
Limited ability to handle parallel events and make dynamic changes
Best suitable for projects with well-defined and stable requirements.
Prototype model
The Prototype model focuses on early user involvement and emphasizes active user participation throughout the development process. It aims to gather user feedback and requirements earlier to ensure the final product meets their needs effectively. In the Prototype model, the result of each iteration is a working prototype of the software that showcases its specific features.
A distinguishing feature of the Prototype SDLC model is the emphasis on creating a working prototype of the software early in the development process.
Pros:
Gathering user feedback at early stages.
Easy adaptation to rapidly changing requirements.
Increased chances of project success.
Cons:
Planning the project becomes challenging as prototypes can continue evolving indefinitely.
Developing multiple prototypes can incur significant costs
The absence of a clearly defined project scope and the risk of scope creep due to ongoing prototyping.
Best suitable for projects with innovative or novel concepts.
Incremental and Iterative model
Such a model divides the development process into small increments. Each increment is built upon the previous one, gradually adding new functionality until the complete system is achieved. It involves repeated cycles of requirements gathering, development, testing, and feedback. Each iteration adds new features or refines existing ones.
A distinguishing feature of Incremental and Iterative SDLC is feature prioritization. The most critical features are implemented in the early increments, while less crucial features are added in subsequent increments.
Pros:
It is easier and more cost-effective to incorporate changes in project requirements.
Early feedback from the client is obtained.
Testing and fixing smaller software components are more manageable.
Cons:
Despite some flexibility, proper planning of the system from the beginning is crucial; otherwise, it may not be possible to divide it into modules.
While it may be cost-effective to release individual modules, the overall expense of the system will increase as new modules are integrated
Breaking the system into segments is not always feasible.
Best suitable for projects where stakeholders require early value delivery and for startups passing investment rounds
DevOps model
DevOps is a relatively new SDLC model. It emphasizes collaboration between development and operations teams and tends to automate software development phases. In the DevOps approach, small changes to the code base are immediately tested by automatic tools and deployed into a production environment.
Two distinguishing features of DevOps SDLC are continuous integration (CI) and continuous delivery (CD). The first merges code changes frequently, and the second automates the deployment process.
Pros:
Faster time-to-market
Improved collaboration and communication between team members
Enhanced quality and stability of the software
Cons:
Initial learning curve
Complex implementation
Increased dependency on automation
Best suitable for projects that require frequent software releases.
Evaluating project-specific factors for SDLC model selection
It's essential to consider various project-specific factors when selecting the most suitable SDLC model. These factors can help you choose an appropriate development approach, create a detailed software requirements document, and get the maximum outcome from your development efforts. Here are the factors to consider:
Team size and composition
The size and composition of your development team play a crucial role in determining the appropriate SDLC model. For example, larger teams with diverse skill sets may benefit from models that allow for parallel workstreams, such as the Agile or Spiral models. Whereas, smaller teams may find the Waterfall or Incremental models more manageable due to their linear and sequential nature.
Client involvement
The level of client involvement expected during project implementation plays a significant role in selecting the SDLC model. If your project demands continuous feedback and collaboration with customers, Agile or Prototype models, which prioritize client involvement, may be more suitable. For projects with minimal client involvement, such as internal systems, the Waterfall or V-shaped models could be appropriate.
Risk tolerance
Different SDLC models offer varying levels of risk management and mitigation strategies. If your project has a low-risk tolerance and requires comprehensive risk analysis at each stage, the Waterfall or Spiral models, with their emphasis on thorough planning and documentation, may be more appropriate. Conversely, if your project can accommodate more flexibility and adaptability, Agile or Iterative models, with their iterative feedback loops, can help address risks more effectively.
Project сomplexity
The complexity of the project should be taken into account when evaluating SDLC models. Complex projects with intricate requirements may benefit from models that emphasize flexibility. In this case, Agile or Iterative models are a good fit. Projects with clear requirements, which are unlikely to change over time, may take better advantage of models focusing on sequential and phased development. This is when Waterfall and V-Shape models can serve well.
Time-to-market requirements
The urgency of delivering the project within specific time constraints is another factor to consider. Some projects may have strict deadlines or market demands that require a faster turnaround. In such cases, SDLC models like Prototype or Incremental models can be more suitable because they prioritize the quick delivery of working prototypes. These models allow for early releases and frequent iterations, enabling faster time-to-market.
Knowing when to say no to Agile
Agile is undoubtedly one of the most progressive methodologies today. It allows for quick adaptation to changing business and market requirements and delivers the best results in the shortest possible time. However, the choice of Agile methodology should be based not on its popularity but on its suitability for the project. There are situations where Agile cannot meet the requirements of specific workflows, as discussed below.
Hardware projects
Hardware projects are characterized by their reliance on interactions with manufacturers and extended development phases. For instance, when creating smart locks, a comprehensive hardware specification must be established, followed by discussions with the manufacturer and then production of the components. The process before receiving a finalized prototype can span several weeks or even months. Meanwhile, the software team focuses on developing the software aspect. Due to the close interdependence between the hardware and software components, the software team is limited in making significant alterations to the product under development. Consequently, the Agile methodology, with its emphasis on short iterations and evolving requirements, is not well-suited for this scenario.
Fixed Price projects
Fixed-price projects are characterized by their small scale and short duration, with a pre-established budget. In these projects, the product's features, technology stack, team composition, and desired outcome are thoroughly discussed upfront. One significant advantage for clients in a fixed-price project is the certainty of knowing the exact cost of product development, without incurring additional expense if the team exceeds the budget. Consequently, Agile methodologies, which embrace changing requirements and variable costs, are not well-suited for such projects. This is because they cannot (and do not aim to) foresee all project variables in advance.
Projects with limited client involvement
One of the main requirements of Agile projects is active client involvement. At the end of each iteration, the client participates in the discussion of results and planning for the next iteration. Based on this, short-term goals are set and tasks are distributed among team members. However, there are projects in which the client has minimal involvement. Such projects are usually focused on the development of internal tools or software applications to improve operational efficiency within the organization. The client, in this case, would be the internal department or team benefiting from the tool. They may provide initial requirements, but the development team would have autonomy in designing and implementing the tool based on their expertise.
Ready to launch an effective software development project?
Every software development project is unique and has its own set of resources, characteristics, and goals. It is designed to achieve something specific while overcoming particular challenges and obstacles. In order to succeed, thorough analysis, careful planning, and a tailored development approach are essential.
At Erbis, we understand the importance of treating your project as a one-of-a-kind. We know how to select the software development model that will yield the best results for your clear-cut needs. Contact us today to discuss your development journey and set it on the path to success.
