Software spiral model

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.

Since risk monitoring and regular expertise are core characteristics of this methodology, the overall project becomes more transparent. 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. 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. This is where everything starts.

Team members try to gather the product objectives, requirements e. Thus, permanent communication between customer and project management is crucial. What are the risks in this context? Risks are possible conditions and events that prevent the development team from its goals. 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. This is when the planned product is developed along with further testing. 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. 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. Not at all. In fact, Spiral model is pretty flexible. Real life project life cycle is more agile and flexible than this simple representation. XB Software team applied some principles of Spiral model, and also Scrum principles.

For example, shorter iteration to make more frequent releases in order to receive feedback more quickly. Besides, a detailed plan describing what to develop for just one iteration was created. Other requirements were documented in the backlog or roadmap.

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 the users and the market. On this stage, there was only the initial vision of the product that can create value to the potential 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.

The exact number of phases needed to develop the product can be varied by the project manager depending upon the project risks. As the project manager dynamically determines the number of phases, so the project manager has an important role to develop a product using the spiral model.

The Radius of the spiral at any point represents the expenses cost of the project so far, and the angular dimension represents the progress made so far in the current phase. The below diagram shows the different phases of the Spiral Model: — Each phase of the Spiral Model is divided into four quadrants as shown in the above figure.

The functions of these four quadrants are discussed below-. Skip to content. Change Language. Related Articles. Introduction of Software Engineering. Software Requirements. This blog will cover the following: 1. What is Spiral model? Understanding each quadrant stages of the model. Benefits of the spiral model. Drawbacks of the spiral model. When to use the spiral model? Diagram of Spiral Model described by Boehm It is also known to be based on evolutionary development as the primary and important features are defined, developed and deployed first and then other necessary features are added with each the spiral or phases of the project.

Understanding Each Quadrant of the Spiral Different quadrants of Spiral Model As you can see the figure above, the spiral model contains four different quadrant stages from which the web development process passes through repeatedly. Determine objectives, alternatives and risks 2.

Evaluate alternatives and resolve risks 3. Development and testing 4. Plan next phase 1. Determining objectives, alternatives and constraints Figure — 1st Quadrant This is the initial stage where all the requirements are collected, objectives are defined, constraints are evaluated and different alternative solutions for the development are proposed.

Evaluating alternatives, identifying and resolving risks Figure — 2nd Quadrant At this stage, all the proposed alternative solutions are evaluated and the best is selected for the development. Evaluation and plan for the next phase Figure — 4th Quadrant This is the last stage of the spiral where the developed project is evaluated and new plans are formulated for the next phase.

What are the Benefits of the Spiral Model? Flexible This SDLC model is highly flexible as changes can be incorporated during the later iteration of the development.

Risk Management With the spiral model, risks are analyzed at each and every phase of the product before moving forward. Customer Involvement and Feedback Customers are involved in each phase of the project until the project is completed.

Perfect for a large project The spiral model is considered to be the most preferable software development life cycle model for large and complex projects. What are the Drawbacks of the Spiral Model? Expensive The spiral model can be quite expensive as it requires a high level of expertise for risk analysis. Time Management One of the disadvantages of the spiral model is the time management as the number of phases are unknown.

Wrapping up Why implementing the spiral model to your Web App Development is a good idea? So, when you must use the spiral model for your web application? We recommend you to use the spiral model for your project if: — The project requirements are not clear or complex — For a large and long-term project — Edits and updates are to be made during the development process — When the risk is medium to high.

Goldy Benedict Content Manager.