About Spiral model is a risk-driven process model generator for software projects based on the unique risk patterns of a given project. In this model, the whole process of software development is divided into different phases. At each stage, some aspects of requirements are considered, and some concrete deliverables are produced. The phase in each iteration is then planned and managed using a defined process. Different from the waterfall model, the spiral model isolates and evaluates the different phases of development in isolation. Each phase starts with a design goal and ends with the client reviewing the progress. If the client approves, you can continue to next phase if not possible to go back to one or more previous phases
The Spiral Model
About 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 is also known as the spiral method, spiral development, and spiral lifecycle. Although it has similarities with other lifecycle models (such as waterfall or agile), it offers benefits by using iterative development techniques to allow for earlier testing.
Each phase is managed using a defined process
At each stage, some aspects of requirements are considered, and some concrete deliverables are produced. Let’s look at the requirements, there are two main types of requirements:
- Business or Functional Requirements describe what the system should do, such as order a product. These are often described in terms of input and output, with no reference to how they will be implemented (the technical solution).
- Non-Functional Requirements specify aspects such as performance, usability, and reliability; they relate to what the system has to accomplish. In some cases, these may be more important than others depending on your business goals and objectives (see below).
The phase in each iteration is then planned and managed using a defined process
About spiral model is a risk-driven process model generator for software projects based on the unique risk patterns of a given project. The whole process of software development is divided into different phases. All these phases have their own objectives and deliverables which are achieved through iteration cycles. In each iteration, there are four main tasks that need to be done:
- Define functionality
- Identify risks and uncertainties
- Plan & manage work
- Control quality
Different from the waterfall model, the spiral model isolates and evaluates the different phases of development in isolation.
The spiral model is an iterative approach, not a linear one. This means that unlike the waterfall model where all phases of development are completed in sequence before moving onto the next phase, with the spiral approach, you complete each phase and then return to it multiple times with increasingly detailed information.
With each iteration of what’s called a “spiral cycle” you:
- Get client approval for your design documentation (or at least get feedback from them).
- Identify new requirements and goals based on this feedback. In other words, ask yourself “If I knew everything my client could tell me about what they need now, what would it be? What features would we add or remove? Would we focus on different parts of our project? What would change about our timeline or budget?”.
- Make any necessary changes based on these new insights into how people use your product or service. You can even go back as far as start over again, if necessary, but don’t let yourself fall behind!
Each phase starts with a design goal and ends with the client reviewing
The design goals for each phase should be achievable in the time allowed. This is especially important when a project begins. If your client requests something that is unachievable within the timeframe, you can ask them to revise their request or draw up a new plan for how to achieve it within the time allotted.
The client should be involved in every phase of development and have the power to approve or reject your work at the end of each phase. By involving them early on, you will have less issues later because they will know what they want before they see any results from your work.
If there are any problems with what you produce, you can go back to any previous stage and redo as needed until everything is perfect before moving onto the next step.
If the client approves, you can continue to the next phase
This allows for incremental releases of software product at every cycle or iteration. The spiral model takes advantage of a team’s experience by using feedback to improve the software (i.e., applying design patterns) and continuously evaluate the product through evaluation criteria such as function, quality, features, performance, and usability. This iterative approach helps in building a better product which eventually will come out with more enhanced features than in earlier iterations due to continuous improvement from each phase up until all requirements are fulfilled.
About Spiral Model to any previous stage at any time
In about Spiral Model, you can go back to any previous stage at any time. It does not mean that your software will become obsolete after going through the same process again. You can also go back to the previous phase and continue working on it until you feel it’s ready for next iteration or stage. This is different from waterfall model where you can only go forward, i.e., from Planning to Designing to Testing phases in a sequential order without going backward or skipping any of those steps.
If you are using this model, then it is important to note that the software development process can be iterative. This means that you don’t need to worry about getting stuck at any stage of the project. You can always go back to a previous stage or iteration and continue with your project from there. This way, you will be able to deliver high-quality software products on time without compromising on quality or scope of features required by clients.