Spiral Model in Software Engineering

If you find spiral model confusing.Then read this article.This article will help you in understanding different phases of spiral model.

‍The Spiral Model in Software Engineering is similar to the incremental model, with more emphasis placed on risk analysis. The spiral model has four phases: Planning, risk analysis, product development and next phase planning or Evaluation. A software project repeatedly passes through these phases in iterations (called Spirals in this model).

When looking at a spiral model diagram, the spiral’s radius represents the project’s cost, and the angular degree represents the progress made in the current phase. Each phase begins with a goal for the design and ends when the developer or client reviews the progress.

Table of contents

• What is spiral model?
• Why spiral model is called meta model
• Risk handling in spiral model
• Applications of spiral model
• Spiral model phases
• Benefits of the spiral model
• Limitations of the spiral model

What is Spiral Model?

The spiral model is a systems development lifecycle (SDLC) method used for risk management that combines the iterative development process model with elements of the Waterfall model. The spiral model is used by software engineers and is favored for large, expensive and complicated projects.

Why is Spiral Model Called Meta Model?

The Spiral Model is a software development framework that combines other development models’ iterative and incremental nature with a risk management component. As a “meta-model,” it provides a systematic approach to identifying and mitigating risks throughout the software development life cycle.

The model consists of four phases – planning, risk analysis, engineering, and evaluation – which are executed in a cyclical manner, with each cycle building on the previous one. This makes it a highly adaptable framework that can be used to guide and adapt any software development process.

Due to its flexibility and risk management focus, the Spiral Model is a popular choice for complex and large-scale software projects. It enables software development teams to identify potential risks early on and adjust the development process accordingly, ultimately leading to a higher quality product.

By incorporating the Spiral Model into their software development process, teams can increase their efficiency, reduce risk, and ensure that their software products meet the needs of their users.

Also explore:What Does A Software Engineer Do? Roles, Responsibilities, and Skills

“The spiral model is called the metamodel” because it encompasses other software development lifecycles. For example, a single loop spiral actually represents an iterative waterfall model. Spiral models use prototype models to create prototypes before starting actual product development. A spiral model allows you to mitigate risk and take a systematic approach. Spiral models can also be viewed as supporting evolutionary models.

Risk Handling in Spiral Model

The spiral model analyzes all proposed solutions and identifies, analyzes and addresses all potential risks. Following this, methods such as prototyping, simulation, benchmark testing, analytical models, and user research are used to develop the lowest-risk, most cost-effective strategy.

Spiral Model Phases

The different phases of the spiral model are-

1. Planning

This phase begins by gathering business requirements into a baseline spiral. In the subsequent spiral, all system, subsystem and unit requirements are identified at this stage as the product matures. 

This phase also includes understanding system requirements through ongoing customer and system analyst communication. The product will be deployed in the identified market at the end of the spiral. This includes iteration cost, schedule, and resource estimates. This includes understanding system requirements for ongoing communication between system analysts and customers.

2. Risk Analysis

After the “plan” phase, the team prepares for the “risk” phase. The “risk” phase is designed to consider the variability in the rate at which a given product might fail. It is designed to account for the uncertainty in the rate at which a given product might fail. During the “risk” phase, the team evaluates various aspects of the current state of the product, such as the state of its code, the state of its design, and the state of its prototype. The team then makes adjustments to the current state of the product based on the changes made in the “plan” phase and then follows up with a “sales” phase to collect customer feedback.

Once  risks are identified, risk mitigation strategies are planned and completed. 

Briefly, risk analysis involves identifying, estimating and monitoring technical feasibility and management risks such as schedule slippage and cost overrun. After testing the build, customers rate the software at the end of the first iteration and provide feedback.

3. Product development

In the next quadrant, prototypes are built and tested. This step includes architectural design, module design, physical product design and final design. Convert the proposals made in the first two quadrants  into usable software.

This phase also includes the actual implementation of features in a project, which are verified by performing testing.

4. Next phase planning

In this phase, the customer evaluates the software and gives feedback. The team prepares for the next phase of the planning process. The next phase of the planning process is known as the “spiral” phase. During the “spiral” phase, the team determines the order of events in the current state of the product and then follows these events up with a “revision” phase to “Revise” the current state of the product so that it is ready for production. The “revision” phase is also called the “reproduction” phase, one of the most important aspects of the planning process.

Applications of Spiral Model

1. Spiral Model in Web Based Applications

The spiral model splits the whole process into different modules. As a result, the module is delivered to the customer. You can use it from the beginning. The proposed model is also beneficial when customer requirements change. Along the way, it is easy to implement during development. Progress your project step by step.

2. Use of Spiral Model in Mobile Application Development 

Mobile Application Development Life Cycle (MADLC) combines the traditional Prototype and Spiral Model. In mobile application development, we need to take under deliberate aspects like cross-platform development, the way of interacting with users and memory usage (since low memory space is a common issue in mobiles).

Benefits of the Spiral Model

The benefits of the spiral model include:

• The spiral model works for development as well as enhancement projects.

• The spiral model is a software development model designed to control risk. The major distinguishing feature of the spiral model is that it creates a risk-driven approach to the software process rather than a primarily document-driven or code-driven process. 
• It incorporates many of the strengths of other models and resolves many of their difficulties.

• Spiral models are ideal for large and complex projects, as continuous prototyping and evaluation help reduce risk. 

•  This model supports customer feedback and the implementation of Change Requests (CR), which is not possible with traditional models such as waterfall. 

•  Customers see the prototype at each stage, which increases the chances of customer satisfaction.

Limitations of the Spiral Model

Here are soem of the limitations of the Spiral model:

• The most obvious limitations of the spiral model are that it does not account for the uncertainty in the rate at which a given product might fail and for the variability in the rate at which a given product might fail. 
• This model does not account for the fact that customers might change their mind about a given product and return it to the supplier. 
• Spirals can continue indefinitely. As the spirals continue to increase, the project’s cost also increases. 
• Many intermediate stages require excessive documentation. 
• Spiral models are best suited for projects rather than large complex small projects as continuous prototyping and evaluation help reduce risk. 
• The number of phases is initially unknown, and frequent prototyping and risk analysis can exacerbate the situation, so project deadlines may not be met. 
• This is very expensive and time-consuming as each stage involves prototyping and risk analysis.

Conclusion

Each spiral in this model can be called a loop, a separate development process for the spiral model. Four activities (Planning, Risk Analysis, Engineering, and Evaluation) form the intermediate phases of the spiral model and are repeated for each loop. 

Happy Learning!!!