Spiral Model is not so well-known as other SDLC (Software Development Life Cycle) models such as Scrumor Kanban, for example. And here’s the reason. Spiral Model can be pretty costly to use and doesn’t work well for small projects.
It’s a risk-driven model which means that the overall success of a project highly depends on the risks analysis phase. Risk analysis requires specific expertise on every iteration. Thus, to review and analyze the project from time to time, special skills are needed.
At a first sight, it may seem like this model is complicated and clumsy, and there are no reasons to consider this approach as one of your options. But, like any other SDLC models, Spiral Model, besides its disadvantages, has its unique strong sides.
For example, there’s a possibility to add some additional functionality at the last stages of software product development. Since risk monitoring and regular expertise are core characteristics of this methodology, the overall project becomes more transparent.
Spiral Model Brief Review of Main Characteristics
In a few words, Spiral Model of software development can be characterized by repeatedly iterating a set of elemental development processes and eliminating risk, so it is actively being reduced.
To understand how you can get your goals using Spiral Model, let’s take a look at this diagram:
As you can see, the Spiral Model consists of four main software development life cycle phases. The whole development process repeatedly passes through these stages. Each iteration is called Spiral.
Four main phases of Spiral Model are:
- Determine Objectives
- Alternatives
- Constraints
- Planning Phase
This is where everything starts. Team members try to gather the product objectives, requirements (e.g. Business Requirement Specifications or BRS, System Requirement Specifications or SRS), alternatives in design, etc. In the subsequent spirals, all requirements are generated according to the customer’s feedback. Thus, permanent communication between customer and project management is crucial.
Evaluate Alternatives, Identify, Resolve Risks or Risk Analysis Phase is probably the most significant development stage.
What are the risks in this context? Risks are possible conditions and events that prevent the development team from its goals. There’s a wide range of them, from trivial to fatal. The primary task for the development team is to enumerate all the possible risks and prioritize them according to importance. The next step is to determine the potential strategies that can help to overcome the risks. Evaluation of these parameters can cause changes in the next steps. At the end of this stage, a prototype is produced.
Develop, Verify Next Level Product, or Engineering Phase.
This is when the planned product is developed along with further testing. During the first spiral, when the overall requirements are not so clear, the so-called Proof Of Concept (POF) is created to get the customer’s feedback. Later, in subsequent spirals, a working version of a product called build can be developed and sent to the client to get new, more detailed, feedback. Such an approach allows achieving higher clarity on requirements.
Plan Next Phases, or Evaluation Phase.
This phase allows evaluating the output of the project to date before the project continues to the next spiral.
Spiral Model is called meta-model because it uses both Waterfall and Prototype models. But it’s highly important to understand that Spiral Model is not just a sequence of waterfall increments. Not at all.
Read AlsoWaterfall Software Development Life Cycle (SDLC) Model
In fact, Spiral model is pretty flexible. You should remember that the diagram we’ve talked about earlier contains some oversimplifications. It may seem that everything on the project follows a single spiral sequence while it’s not. Real life project life cycle is more agile and flexible than this simple representation. There’s even a possibility to revisit the previous decision.
Let’s take a look at the real project to see how Spiral Model of software development works.
Real Project Example. How GanttPRO WasMade
To provide a greatexample, we will consider our startup Gantt Chart Software –GanttPROa tool for simple task handling.
XB Softwareteam appliedsome principles of Spiral model, and also Scrum principles. For example, shorteriteration to make more frequent releasesin order toreceive feedbackmore quickly. Besides, a detailed plan describing what to develop for just one iteration was created. Other requirements weredocumentedin the backlog or roadmap.
The main issues the GanttPROteam faced were:
- Unpredicted requirements which were not fully known at the beginning and needed to beclarified and addedfrom iteration to iteration
- Necessityofrisks analysis and risks management beingthe important stage of Spiral model
- Too many risks that can accrue during development and as a result
- Possible costsincreasecaused by long period of planning and further designing, developing, and implementation
Therefore, following agile principles of SDLC, we chose shorter delivery frequency: two weeks iterations. As a consequence, we managed to reduce risks because of quick adaptation to the needs of theusers and the market.
As a result, the following development stages have been completed:
1. Defining concept
On this stage, there was only the initial vision of the product that can create valueto thepotential users. We wanted to have a possibility to get feedback from our first users as quick as possible. Such conception can help understand more clearly what features are the most valuable for the users. We had some analysis data about features and requirements that should be implemented at first. The main aim was to understand what potential increment we would like to have at the end of the iteration.
2. Inception stage
After we determined the main conception and initial architecture vision, we started to plan our first iteration. The most critical requirements were sent to the top of the list. Then we asked each developer of our team how many requirements they think can be turned into completed functionality. Afterwards, we decomposed each requirement (identified work tasks) and defined the best possible way to develop them. We’ve included modeling and prototyping solution to make a more accurate estimate.
3. Design stage
We elaborated a mockup thatdescribed software functionality and features in detail. The mockup was then processed by our designer. The design elementshad tobe described quite clearly to help a developer build software with minimal additional input.
4. Construction of iteration and testing
At this stage, the team delivered high-quality working software in priority order, which was created in accordance withthe changing needs of our potential users. What’s more important, the team coulddeploy this solution into a pre-production testing/QA sandbox for system integration testing.
5. Installation stage
This stage provides the mechanisms to move the latest application and development changes into production.
6. Post production / Maintenance stage
At the end of each development iteration, we had a partial working solution to show our users. On this basis, users gave us their feedback onthe current state of our system. After collecting and analysing these requirements, we’re able to change the priority of tasks in the next iteration andeven included some requirements from scratch.
Spiral Model Pros and Cons
Each software development model has its own weak and strong sides. Spiral Model is not an exclusion from this rule. Let’s sum up the possible pros and cons of this approach.
Advantages:
- Risk monitoring is one of the core parts which makes it pretty attractive, especially when you manage large and expensive projects. Moreover, such approach makes your project more transparent because, by design, each spiral must be reviewed and analyzed
- Customer can see the working product at the early stages of software development lifecycle
- Different changes can be added at the late life cycle stages
- Project can be separated into several parts, and more risky of them can be developed earlier which decreases management difficulties
- Project estimates in terms of schedule, costs become more and more realistic as the project moves forward, and loops in spiral get completed
- Strong documentation control
Disadvantages:
- Since risk monitoring requires additional resources, this model can be pretty costly to use. Each spiral requires specific expertise, which makes the management process more complex. That’s why Spiral SDLC Model is not suitable for small projects
- A large number of intermediate stages. As a result, a vast amount of documentation
- Time management may be difficult. Usually, the end date of a project is not known at the first stages
Conclusions
Anotherimportant thing to remember is that Spiral Model should be used in that kind of projects it was initially designed for. It can be a good option if you face a medium, or high-risk project and costs are highly important, a customer is unsure completely abouthis needs and requirements are complex, and significant changes are expected.
FAQs
What is the spiral model in software development methodologies? ›
The spiral model is a risk-driven software development process model. Based on the unique risk patterns of a given project, the spiral model guides a team to adopt elements of one or more process models, such as incremental, waterfall, or evolutionary prototyping.
What are the 7 phases of SDLC? ›What Are the 7 Phases of SDLC? The new seven phases of SDLC include planning, analysis, design, development, testing, implementation, and maintenance.
What are the five phases of systems development life cycle SDLC methodology in order? ›The SDLC process includes planning, designing, developing, testing and deploying with ongoing maintenance to create and manage applications efficiently.
How many SDLC methodologies and models are there? ›The SDLC process involves several distinct stages, including planning, analysis, design, building, testing, deployment and maintenance. What's the best SDLC methodology? Here are six models consider.
What are the features of spiral methodology? ›The spiral model has four phases: Planning, Design, Construct and Evaluation. A software project repeatedly passes through these phases in iterations (called Spirals in this model).
What are the 10 phases of SDLC? ›This SDLC methodology establishes procedures, practices, and guidelines governing the initiation, concept development, planning, requirements analysis, design, development, integration and test, implementation, and operations, maintenance and disposition of information systems (IS) within the DOJ.
What is SDLC and its types? ›SDLC is the acronym of Software Development Life Cycle. It is also called as Software Development Process. SDLC is a framework defining tasks performed at each step in the software development process. ISO/IEC 12207 is an international standard for software life-cycle processes.
Why is SDLC important? ›Importance of SDLC
It provides an effective framework and method to develop software applications. It helps in effectively planning before starting the actual development. SDLC allows developers to analyze the requirements. It helps in reducing unnecessary costs during development.
SDLC is a process followed for a software project, within a software organization. It consists of a detailed plan describing how to develop, maintain, replace and alter or enhance specific software. The life cycle defines a methodology for improving the quality of software and the overall development process.
What is system development methodology explain its phases? ›Systems development life cycle phases include planning, system analysis, system design, development, implementation, integration and testing, and operations and maintenance.
What is the best methodology in SDLC? ›
Agile is the best SDLC methodology and also one of the most used SDLC in the tech industry as per the annual State of Agile report. At RnF Technologies, Agile is the most loved software development life cycle model.
What is system methodology? ›It is a methodology for systematically organizing the best ways to develop systems efficiently. It includes, for example, descriptions of work to be performed at each stage of the development process and drafted documents. Multiple methodologies—which differ according to viewpoint—are available.
How many methodology are there? ›Researchers use three primary methodology types: qualitative, quantitative and mixed methods. Within these broad categories, more specific methods include an array of options, such as case studies, self-reporting and surveys.
What are the advantages of spiral methodology? ›Advantages of Spiral Model:
In this model, we can easily change requirements at later phases and can be incorporated accurately. Also, additional Functionality can be added at a later date. It is good for large and complex projects. It is good for customer satisfaction.
Spiral development is a family of software development processes characterized by repeatedly iterating a set of elemental development processes and managing risk so it is actively being reduced. This paper characterizes spiral development by enumerating a few invariant properties that any such process must exhibit.
Where is the spiral model used? ›The Spiral Model is widely used in the software industry as it is in sync with the natural development process of any product, i.e. learning with maturity which involves minimum risk for the customer as well as the development firms. When there is a budget constraint and risk evaluation is important.
What is SDLC analysis? ›Analysis
The analysis phase also gathers business requirements and identifies any potential risks. This step in SDLC also includes a feasibility study, which defines all fortes and weak points of the project to assess the overall project viability.
In SDLC, the design phase is a stage where software developers define the technical details of the product. Depending on the project, these details can include screen designs, databases, sketches, system interfaces, and prototypes. Clients use these details to make final product design choices.
What are the three phases of the SDLC methodology? ›- Stage 1: Project Planning. ...
- Stage 2: Gathering Requirements & Analysis. ...
- Stage 3: Design. ...
- Stage 4: Coding or Implementation. ...
- Stage 5: Testing. ...
- Stage 6: Deployment. ...
- Stage 7: Maintenance.
SDLC stands for Software Development Life Cycle models, and these are a variety of processes of design, development and testing that are used in the industry today. While there's no best or standout SDLC methodology, it's essential to be across the most common models that can be applied to projects within a company.
What is a SDLC diagram? ›
A software life cycle model (also termed process model) is a pictorial and diagrammatic representation of the software life cycle. A life cycle model represents all the methods required to make a software product transit through its life cycle stages.
What is SDLC example? ›SDLC provides a well-structured flow of phases that help an organization to quickly produce high-quality software which is well-tested and ready for production use. The SDLC involves six phases as explained in the introduction. Popular SDLC models include the waterfall model, spiral model, and Agile model.
What is spiral model with example? ›...
Advantage and disadvantage of the spiral model.
| Advantage | Disadvantage |
|---|---|
| Flexible changes are allowed in spiral model. | It is not suitable for the small and low-risk product because it could be costly for a smaller project. |
The spiral model is a risk-driven process model generator for software projects. Based on the unique risk patterns of a given project, the spiral model guides a team to adopt elements of one or more process models, such as incremental, waterfall, or evolutionary prototyping.
Where is the spiral model used? ›The Spiral Model is widely used in the software industry as it is in sync with the natural development process of any product, i.e. learning with maturity which involves minimum risk for the customer as well as the development firms. When there is a budget constraint and risk evaluation is important.
What is Agile or spiral methodologies? ›The Agile model focuses on the delivery of an increment to the customer after each Time-box, so customer interaction is more frequent. The spiral model mainly deals with various kinds of unanticipated risks but customer interaction is less.
Why spiral model is called? ›Why Spiral Model is called Meta Model? The Spiral model is called a Meta-Model because it subsumes all the other SDLC models. For example, a single loop spiral actually represents the Iterative Waterfall Model. The spiral model incorporates the stepwise approach of the Classical Waterfall Model.
What does SDLC mean? ›The Software Development Life Cycle (SDLC) is a structured process that enables the production of high-quality, low-cost software, in the shortest possible production time.
Who process the spiral model? ›The spiral model, initially proposed by Boehm, is an evolutionary software process model that couples the iterative feature of prototyping with the controlled and systematic aspects of the linear sequential model.
What is spiral model write its advantages? ›Advantages of Spiral Model:
Software is produced early in the software life cycle. Risk handling is one of important advantages of the Spiral model, it is best development model to follow due to the risk analysis and risk handling at every phase. Flexibility in requirements.
How is spiral model different? ›
...
Difference between Waterfall Model and Spiral Model.
| S.NO. | Waterfall Model | Spiral Model |
|---|---|---|
| 1. | The Waterfall model is simple and easy. | The spiral model is a lot more complex. |
| 2. | Waterfall model works in sequential method. | While spiral model works in evolutionary method. |
Born out of real-world software development projects, Spiral Framework is a modern PHP framework designed to power faster, cleaner, superior software development. GitHub Documentation.
What is spiral testing? ›Spiral Testing. Spiral testing is a risk based testing, where testers will take risk due many factors at the same time they will equipped with solutions for that risks. In the spiral and rapid application development testing environment there may be no final functional requirements for the system.
What is risk analysis in spiral model? ›Risk Analysis: In the risk analysis phase, a process is undertaken to identify risk and alternate solutions. A prototype is produced at the end of the risk analysis phase. If any risk is found during the risk analysis then alternate solutions are suggested and implemented.
What type of methodology is spiral? ›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.
What type of methodology is Agile? ›Agile methodology is a “step by step” dynamic focused on short-term visibility but never losing the long-term product goal. There are 5 main Agile methodologies: Scrum, Kanban, Extreme Programming (XP), Lean Development e Crystal.
What is Agile methodology called? ›Agile methodologies frameworks
Agile project management can refer to terms including Scrum, Kanban, Extreme Programming (XP), and Adaptive Project Framework (APF).