Spiral Model For Software Development- A Risky-Driven Model

The spiral model for software development is the best-chosen software model for risky, extensive and complicated projects. In its graphical representation, it looks like a spiral net with many loops. However, the number of loops depends on the project type and requirements. Each loop in the spiral model is also a phase of the software development process. 

Initially, Barry Boehm mentioned the spiral model in one of his papers, “Spiral Model of Software Development and Enhancement,” in 1986. The spiral method software development process is a combination of the iterative development model and waterfall model in software engineering. 

The spiral model for software development starts with collecting a small set of requirements and goes through a small development phase. Unlike the waterfall model, software engineering terms have the freedom to add any functionality at any increasing spiral phase. 

What Is Spiral Model For Software Development?

The spiral model for software development is a software development model that combines elements of both iterative and incremental development methodologies. 

In 1986, it was initially proposed by Barry Boehm and established as a well-suited model for large, complex projects where risks need to be managed effectively. The Spiral Model is characterized by its emphasis on risk analysis and management throughout the software development lifecycle.

Graphically, the spiral model consists of multiple phases that are executed in a cyclic or spiral fashion, with each iteration referred to as a "spiral."

• Planning
• Risk Analysis
• Engineering
• Evaluation

The essential characteristic of the spiral model is it follows an iterative and incremental approach, which allows flexibility and adaptation as the project progresses. 

One of the main advantages of the Spiral Model is its ability to accommodate changes and address risks proactively.

Overall, the Spiral Model is a valuable approach for managing software development projects that require a flexible and risk-aware methodology.

Phase Of Spiral Model Software Development Life Cycle

1. Planning (Requirement Gathering)

Just like any other model like SDLC Agile model, V-shape model, and waterfall model, spiral model SDLC also follows the planning phase very significantly. 

The primary purpose of the planning phase in the spiral model SDLC is to collect, understand and identify the core objectives and set some alternative solutions. 

Moreover, it also gathers elaborative details of every small requirement. Graphically, the planning phase of the spiral method of software development starts from the baseline spiral. As the software development progresses, it creates a prototype of software, plans alternative solutions and finalizes the list of changes. 

2. Risk Analysis (Risk Management)

In this phase of the spiral model for software development, the developer term will identify all the potential risks that will arise during the software development process. 

After the developer is done with problem identification, the software engineer will plan a list of strategies to mitigate the risks. In short, this phase is all about risk management along with the technical feasibility. 

After the risk identification process, the developer team will release a prototype, which will be a risk-free demographic version of the software. Not only will the developer release a risk-free prototype, but they also will plan alternative solutions to handle the risk.

3. Engineering (Designing and Coding Phase)

This phase starts with designing the leading software by idolizing the prototyped design from the baseline spiral. The prototype design will be a guideline for software architecture, logic, front-end and final design. 

After the software engineering is done designing the software, they will start coding, testing and the deployment process. Moreover, developers will deploy the software on the client’s site to gather feedback. This phase in the spiral model is totally technical and needs experience and expertise to tackle any challenge or change.

4. Evaluate (Review And Deployment)

After the launch of a software project on the client’s site, the client is open to sharing feedback and insightful observations about the software. 

Hence, the testing team from the client side will note down all the feedback, observations, additions and changes needed in the software or its functionality. All the correction lists will be sent to the development team, 

Again, a new baseline will begin to fix all the bugs, and after fixation of all requirements, the final product will be ready for final launch.

Spiral Model Advantages And Disadvantages

Even though there are several software development life cycle models, the spiral model is best for handling large and complicated software development projects. But there are still some significant advantages and disadvantages of the spiral model, which we have to face while in the development process. 

Advantages Of Spiral Model 

• Best Model To Handle Risky Projects: indeed, many unknown risks arise through the development process. The spiral model is the perfect pick for a risky and complicated project. 
• Good Choice For Large Project: With the spiral model, it is expertise in handling large and complex projects. 
• Flexible With Requirements: The spiral model is adaptable to any changes/ additions at any phase at any time.  
• Better Customer Satisfaction: The client can overview during the early phase of the software development process and, hence, will be habituated even before launching the final stage.
• Iterative and incremental approach: The spiral model follows a sequential combination of iterative and incremental models in software development, hence facilitating adaptability to any requirement change. 
• Prominent to handle risky projects: The spiral model specializes in handling any risky project, hence reducing the impacts of uncertainty during the software development process. 
• Open to receiving any feedback: The spiral model appreciates regular evaluation/review of the software project, thus a great chance to improve the software during the development process.
• Better quality: Because of multiple iterations in the whole software development life cycle, you get an improved and quality outcome.

Disadvantages Of Spiral Method 

• Complexity: The spiral model in the software development life cycle is as complicated as it looks diagrammatically. 
• Expensive: The spiral method is not suitable for small or medium size software projects.  
• Too much dependency on experts: How much the project will be successful depends on the risk analysis and experience of the expert developer. 
• Poor time management: Spiral models have an unknown number of phases; therefore, it is complicated to track the software project deadline.
• Follows multiple iterations: As per the spiral model diagram, the spiral model SDLC itself is complicated and involves multiple iterations, thus becoming more complex. 
• Time-consuming: Spiral methodology goes through multiple iterations, several feedbacks, and too many changes during the development process, thus taking time to finish the software project. 
• Require intensive investment: Spiral method software development handles risk-oriented software projects and hence requires a significant amount of investment in planning, risk analysis and evaluation.

Risk Handling In Spiral Model For Software Development  

Indeed, the spiral methodology is best for handling risky projects, but it still has to face severe challenges to correct the changes. Any risk in a software project might affect the development progress. 

The spiral model follows in developing a software prototype earlier before going to the coding phase of software design. Hence, it is easier to solve the maximum risks in the “risk analysis phase“. 

Even though we all expect the bugs or faults to be solved before the software prototype, in reality, project risk rises when developers actually start developing the software. 

All of this risk management hassle will get solved flexibly only because of this spiral model. According to the spiral model, through building software prototypes, every feature is analyzed and tested, fixed the bugs and solved the identified changes. 

When To Use The Spiral Model Phase?

The spiral model for software development is usually known for handling risk-oriented, large, expensive and complicated projects. The spiral model is the most used SDLC process since it automatically synchronizes with the natural software development lifecycle process. Below, I have mentioned project types that are perfect for using the spiral model phase.

• Handles medium to high-risk project 
• Project requirements are unclear and complex 
• Changes can be made at any phase of the project 
• When prototype creation is mandatory
• Not at all feasible for long project commitment 
• Project release is frequent 
• Risk mitigation and cost evaluation is crucial 

Conclusion 

The Spiral Model for software development lifecycle offers a flexible and iterative approach that addresses the inherent uncertainties and complexities of modern software projects. 

Its cyclic nature, combining planning, design, implementation, and testing, allows for continuous refinement and adaptation to changing requirements and risks.

By emphasizing risk management and customer feedback, the Spiral Model encourages transparency, collaboration, and the delivery of high-quality software products. 

While it may not be suitable for every project, it remains a valuable tool in the arsenal of software development methodologies, mainly when dealing with projects where uncertainty and evolving requirements are prevalent.