Among the best models of software development is the waterfall model, in which tasks are carried out in a sequential fashion, beginning at the top with feasibility and moving down through different tasks to implementation in the real world. Requirements influence the design, which influences the building or implementation, which influences testing, and so on. It has been challenging to pass the feedback to the waterfall because testing happens at the end of the model. So, we need to know the history of waterfall model so that we can have a deep understanding on how this model works.
Frameworks, programs, and other software components are created and maintained as part of the software development process. This process comprises steps like requirements analysis, specifying requirements, designing, building, testing, and maintaining the software product. You can choose from a variety of software design models depending on the project’s goals, requirements, and constraints. The Waterfall Model will be covered in detail in this essay, with special attention paid to the logical flow of this development life cycle.
One of the earliest process models for software development was the waterfall model, sometimes referred to as the linear-sequential life-cycle model. The descending mechanism in this model is comparable to a waterfall, as the name suggests. The process is broken down into steps that must be successfully completed in order to proceed to the following ones. The Waterfall Model contains six steps, according to the International Software Testing Qualifications Board:
When working with the waterfall model, it is important to comprehend how it will be used based on both internal and external aspects.
- No unclear application requirements.
- Product definition stability
- It is aware of technology but is not dynamic
- To support the product, there are numerous resources with the required skills available.
- A brief project
- Good paper with precise needs.
History of waterfall model that we need to know
Felix Torres and Herbert D. Benington gave the first presentation on the topic of using these phases in software engineering on June 29, 1956, at the Conference on Advanced Programming Methods for Digital Computers. The creation of programs for SAGE was the topic of this lecture. The study was reissued in 1983 with an introduction by Benington clarifying that the phases were intentionally organized based on the specialization of duties and pointing out that the process was not actually carried out strictly top-down but rather depended on a prototype.
History of waterfall model that we need to know from 1970-2000
Furthermore, with the History of the waterfall model that we need to know, Winston W. Royce published an article in 1970 that featured the waterfall model’s initial example. Since then, the waterfall model has advised against moving on to a new step before the prior phases have been thoroughly tested, examined, and verified. It highlights the logical order in which phase steps are taken.
Its operation is comparable to how water cascades from a cliff’s edge. Given its methodical downward progression from one phase to the next, this method of software development has been given the moniker waterfall. The waterfall model is widely applied in the world of software development since Winston W. Royce originally published it in 1970. Programming models are used to schedule the various phases of developing an application during the software development process cycle.
- History of waterfall model in 2006
In the history of the waterfall model that we need to know, the first development methodology was introduced in 2006. Which looks like a hierarchical structure as the following images sowing
The figure depicts the initial Waterfall method created by Royce. The procedures involve the determination of requirements as well as design, implementation, verification, and maintenance. Other models divide the requirements phase into the planning and analysis phases, or they convert the requirements stage into the process. Additionally, some models subdivide the Design phase into a Logical Design and Physical Design subphase. But the fundamental underlying ideas continue to be the same as before. The above shown is the simplest form of the waterfall model. It simply takes the requirements of the development phase in its first stage.
The Requirements phase of the Waterfall methodology assumes that almost all requirements can be acquired upfront (Kee, 2006). In this phase, interaction with the user is prioritized as the project manager makes every effort to fully comprehend the user’s requirements.
It is ideal to divide the design phase into two subphases: logical design and physical layout. The system’s analysts use the data gathered during the requirements stage to design the major source of any hardware and/or software system even during the logical design phase. The systems analyst starts by converting the higher-level Logical Design into a Physical Design in accordance with the requirements of certain software and hardware technologies.
The entire code is written during the implementation phase (“SDLC Phases”, n.d.). The Waterfall methodology assigns responsibility for this phase to the programmers, who use the project requirements and specifications to create the applications.
Royce originally recommended the Verification step to make sure the project was fulfilling client expectations. However, this stage is frequently skipped during analysis and design in the actual world. The customer is introduced to the project, and the maintenance phase starts.
The customer uses the created application during the Maintenance phase. During this phase, changes to the system are made as issues are discovered as a result of incorrect requirements determination, other errors in the design process, or as a result of modifications to the users’ requirements.
Classic Waterfall Drawbacks that we need to know in the history of the Waterfall Model
This is a classic waterfall model having several drawbacks, most of which are as follows. The traditional waterfall model has a number of drawbacks that prevent us from using it in actual projects. Instead, we utilize different software development lifecycle models that are based on the traditional waterfall model. These are a few of this model’s main flaws:
- No feedback paths
The progression of software from one stage to another in the traditional waterfall approach resembles a waterfall. It is predicated on the idea that developers never make mistakes at any stage. This means that it lacks any method for error correction.
- Vary Requests
Vary requests are challenging to implement because this approach implies that all client requirements can be accurately and thoroughly defined at the start of the project, but in reality, customer requirements change during the course of the project. Any requests for changes just after the requirements specification stage is over are challenging to fulfill.
- No phase overlaps
According to this approach, a new phase should only begin after the preceding one has ended. This, however, cannot be maintained in actual projects. Phases may overlap for cost- and efficiency-saving reasons.
Modern Waterfall Model (2006- till Now)
To answer the question history of the waterfall model that we need to know, The classic waterfall methodology is challenging to employ in a real-world software development project. Therefore, it is possible to think of the iterative waterfall model as adding the essential modifications to the traditional waterfall model to make it applicable to real-world software development projects. With a few adjustments to boost the effectiveness of software development, it is nearly identical to the traditional waterfall paradigm.
The primary distinction between the iterative waterfall model and the traditional waterfall model is the provision of feedback channels from each step to its predecessor phases.
These feedback routes enable the correction of programming faults when they are discovered at a later stage. The feedback channels enable the reworking of the phase where errors are made, and these modifications are mirrored in the subsequent phases. However, there is no feedback route to the feasibility study stage, as once a concept has been accepted, it is difficult to abandon the initiative.
- Phase Confinement of Errors
Phase containment of errors is the idea of discovering errors as close to their places of commitment as possible. Errors should be caught as they are being committed, which is an excellent time to do so. It takes less time and effort to fix the mistakes.
Furthermore, there is another way of modern or iterative waterfall model having some new functionalities and methods.
As compared to the classic model of the waterfall the phases are also rearranged for example the implementation phase is placed at the end because all phases report to the implementation phase. After gathering all the information and requirement implementation takes place and develop the required phenomena. in this modern waterfall model, the design phase is also further categorized.
System Design Phase
This stage involves creating the system design, which outlines the hardware and system specifications, including data layers, programming languages, network architecture, user interface, etc. It contributes to the overall system architecture’s definition, which is further broken down into:
- A phase of high-level design
The initial phase of system design and architecture is this. It includes database tables, architecture diagrams, a list of modules and their functions, and relationships between them. The creation of a High-level Design document marks the conclusion of this phase.
- The preliminary design stages
Designing actual application components is required for this. The preceding phase’s High-level Design is divided up into distinct components. Each module is described in the Low-level Design document as pseudo-code, allowing the programmer to write code directly from the page. It also includes interface information, error-message listings, dependency issues, and I/O for each module.
- Modern Coding Phase
After the design phase in the modern waterfall model, there is also an integration of the Coding phase. This phase facilitates the user to perform the development coding and programming-based works of the developing system. During the coding step, any appropriate programming language is used to convert the software design into source code. Each proposed module is therefore coded. The goal of the unit testing step is to determine whether or not each module is functioning correctly.
Advantages Of the Modern (Iterative) Waterfall Model
There are no reporting pathways in the traditional waterfall approach, hence there is no method for error correction. However, the iterative waterfall model’s feedback channel from one phase to the one before it allows for the correction of errors, and these changes are mirrored in the phases that follow. Iterative waterfall models are relatively easy to use and comprehend. It has become one of the most popular software development paradigms because of this.
Modifying the model’s requirements or strategy is very cost-effective. It also works best for agile businesses.
With this model, less time is spent documenting, allowing the team to concentrate more on designing and developing.
- Simple Layout
The prerequisites, stages, and activities are all clearly laid out. As a result, project managers find it simple to plan, schedule, use resources, and specify targets. The procedure is made simple and straightforward to grasp because each phase has a deliverable.
- It is the preferred strategy for little projects.
- The entire procedure has been meticulously documented and planned.
- There is less requirement for reworking because each phase is distinct and finished within a certain amount of time.
- The deliverables include excellent technical documentation, and the maintenance phase makes it simpler for new programmers to catch up.
- Because of the approach’s strong structure and use of clearly defined milestones, tracking progress is made simpler.
- Change requests are challenging to incorporate
The iterative waterfall model’s main flaw is that all requirements must be spelled out in detail before the development phase can begin. Customers’ needs may vary over time, but the iterative waterfall model leaves no room for incorporating requests for changes that are made after the development phase has begun.
- Time-consuming model
The complete software is produced and tested before being delivered to the customer under the iterative waterfall process. No room exists for any kind of intermediary delivery. Customers must therefore wait a lengthy time to receive the software.
- Phase overlap is not supported
When working on actual projects, stages may overlap to save time and effort. The iterative waterfall model believes that one phase can begin after the previous phase is finished.
- Risk management is not supported
There are many different dangers that can affect a project. However, the Iterative Waterfall Model lacks a risk management system.
- Few interactions with customers
At the beginning of the project, when requirements are gathered, and at its conclusion, when the software is delivered, there is customer engagement. These fewer encounters with clients could cause a lot of issues because the final program may not meet their genuine needs.