When dealing with project management, software development life cycle (SDLC) is a term that often comes up. SDLC is a conceptual model that lays out the stages in a software development project—from the initial planning through maintenance of the finished application. It’s widely considered as the software industry’s spellcheck as it flags errors before they are discovered in much later and more costly stages.
Many people rely on SDLC as it offers a rigid framework to define each step and phase involved in the system development process. Several SDLC methodologies have been created over time, including the original SDLC model—the Waterfall method.
In this guide, however, we will be taking a closer look at the Spiral methodology and how it can benefit your project.
What is the Spiral Model?
Spiral is an SDLC model that combines prototyping and architecture in phases. It functions as a mix of the Waterfall and Iterative SDLC models. Shifting to the next stage is done according to the initial plan—even if the work on the previous stage is not completed yet.
The Spiral methodology is known for being one of the most flexible SDLC models. It has a repetitive cycle—the project goes through four stages (planning, risk analysis, engineering, and evaluation) over and over in a “spiral” formation until it is fully completed. This means there are multiple rounds of refinement for the developers so work is done right the first time.
Risk management is another primary benefit of this SDLC method. Each iteration begins by looking ahead to possible risks and determining the best way to prevent or completely mitigate them.
This model is ideal for large projects that require frequent releases. Because teams have many chances for refinement and user feedback is incorporated early on in the development, the end result is a highly customized product.
Spiral Methodology Phases: the Four Quadrants
When you look at the spiral model diagram, the spiral’s radius represents the cost of the project. Meanwhile, the angular degree shows how much progress was made in the present phase. Each of the multiple phases should start with a goal for the design and conclude once the client or developer is done reviewing the progress.
Every phase can be categorized into four quadrants: defining requirements, performing risk analysis creating a prototype, and evaluating the performance of the application.
These phases start in the quadrant made for the understanding of requirements. The main goal in each stage should be clearly identified and all goals elaborated. Alternative solutions should also be determined in case the attempted software version fails to work according to plan.
After that, risk analysis should be performed on all potential solutions so vulnerabilities will be spotted right away. Some examples would be running out of budget or certain areas in the software that could be open to a cyber attack. The most efficient strategy should be used to resolve each risk.
In the succeeding quadrant, the prototype finally goes through the development and testing stage. This includes the module and architectural design, physical product design, and final design. The end result should be a combination of the proposal created in the first two quadrants.
Lastly, the fourth quadrant is where the test results of the latest version are checked. Through this analysis, software developers have a chance to stop and understand what works and what doesn’t before moving on with a new build. This quadrant concludes as planning for the following phase begins—and the cycle just repeats. The whole spiral ends when the software undergoes full deployment in its target market.
Related Content: A Detailed List of the System Development Life Cycle Phases
Advantages of the Spiral Model
Here are a few reasons why the Spiral model is one of the best SDLC frameworks out there:
- Increase in Customer Satisfaction
Customers can see the product’s development at an early stage, giving them more opportunities for refinement or modification.
- Perfect for Big Projects
The Spiral method is ideal for large and complex projects due to the risk analysis and handling at every phase.
- Flexibility in terms of Requirements
Unlike other methodologies, the Spiral model is quite flexible. Change requests from clients, even at a later phase, can be accurately implemented in this type of model.
- Handling of Risk
There are projects that have several unknown risks that only occur once development kicks off. In those cases, the Spiral model helps a lot as it allows for risk analysis and risk handling at each phase. Better handling of risks means fewer problems down the line.
Limitations of the Spiral Model
Below are the challenges involved with using the Spiral model:
Despite its many benefits, the Spiral model is considered more complex than other SDLC methodologies. It’s one of the reasons why developers use other models instead.
- High Costs
The Spiral model is often used for large projects because it can be quite expensive.
- Dependent on Risk Analysis
One of the primary limitations of this model is it depends too much on risk analysis. When there is a lack of highly experienced developers, there’s a greater chance of failure for projects using this model.
- Time Management Difficulty
At the beginning of the project, the number of phases cannot be determined right away. As a result, estimating the time until completion can be difficult.
SDLC Methodologies: Is Spiral the Right Choice for You?
In the end, the advantages of the Spiral methodologies outweigh the disadvantages. Using this agile method is considered much safer than traditional ways of implementing software projects like the Waterfall model. Compared to other SDLC methodologies, Spiral allows for risk analysis to be performed at every stage, not just once.
The Spiral Model presents an opportunity to progressively build complete software versions by beginning in the middle of the spiral and working outwards. At every loop, the customer has a chance to evaluate the work and make necessary suggestions to modify it.
Customers have constant communication with the developers who implement changes to the system. This results in a substantial increase in customer satisfaction as clients can freely interact with the other stakeholders and control the outcome of the application. So if you're aiming for software that's undergone risk analyses more than once and fully satisfies the client, then the Spiral model is the right choice for your project.