Introduction to the waterfall model
The waterfall model is one of the earliest models of software development, where tasks are performed sequentially, starting from the top with feasibility and through various tasks with implementation into the live environment. Requirements feed into the design, which feeds into construction or implementation, and finally into testing. Since the testing process occurs at the end of the model, routing the feeds up the waterfall was a challenge.
To work on the waterfall model, we need to understand its application approach, which is based on both internal and external factors, which can be as follows:
Web development, programming languages, software testing and others
- No ambiguous requirements in the application.
- Stability of the product definition.
- It's technology understood.
- It's not dynamic.
- Extensive resources with relevant expertise are available to support the product.
- Short length project.
- The good document, clear and firm requirements.
To begin the history of the waterfall model, I would like to say that the first example of the waterfall model was presented in a 1970 article by Winston w Royce. Since then, the waterfall model has said that one should not move to another phase until the previous phases have been fully tested, checked, and verified. It emphasizes the logical sequence of phase steps. Its operation is similar to water flowing over the edge of a cliff.
This software development approach is called waterfall because it systematically descends from one phase to the next. The waterfall model has been widely used in science since it was first published by Winston W. Royce in 1970area of software development. In the software development process cycle, programming models are used to plan the various application phases. One such model is the waterfall model.
Phases of the waterfall model
Below are the phases of the waterfall model:
From the above infographics, we can understand that the waterfall model has a total of 7 phases of the design and development software cycle which are as follows:
- Coding / Implementation
- To test
- Operation / Deployment
So we can see that the waterfall model works hierarchically from top to bottom, completing one phase with full verifications and then moving to another phase including phase processes like conception, initiation, analysis, design, construction, test, production/implementation and Maintenance. To get a concise knowledge of the waterfall model, we need to deeply understand its processes with its working model. A primary prerequisite phase must be understood before the deep phases of knowing begin. It is about the feasibility study for the software product. It addresses the financial and technical aspects of the project requirements. This phase is about correcting the measures based on the analyzed advantages and disadvantages. Thus, the best solution is chosen.
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In particular, we need to know and understand what we need to design, what we need to develop, its processes, its functionality, etc. It provides input material for the product to be manufactured; This is how the upcoming product is examined, completed and marked. It also gives us the opportunity to determine the hardware or software requirements of the product that is designed, developed and captured at all stages.
It leads to designing models, schemas and business rules.
Not only this requirement is divided into two parts:
- Requirements gathering and analysis:First, all information and requirements for product development are collected from the customer and prepared for analysis. The main task of this part is to eliminate incompleteness and inconsistencies related to software product development.
- Requirement Specifications:The requirements analyzed above are then documented in an SRS document (Software Requirement Specification). It serves as a link between the customer and the SRS development team. All future disputes will be managed and resolved solely through this SRS documentation.
After the first phase is completed and verified, this is the next most important phase to study as it is used for system design. It helps to specifysoftware and hardwareProduct design requirements. It also helps in the overall architecture of the system design. Therefore, in this phase, the requirements specification is mainly studied and verified. It is also helpful in transforming the SRS document into a functional design and developing the software product. So we can say that in the design phase one creates the overall architecture for the software development project.
After the system design is fully verified, the implementation phase follows. In this phase, the inputs from the system design are taken over and initially developed in small programs, so-called units, which are tested and implemented in the next phase. Each unit in the implementation phase is developed and tested for full functionality, akaUnit-Tests. In this phase, the system design is implemented in source code with fully functional program modules. It includes the development, testing and integration of the software.
5. Integration and Testing
Each unit design and development in the earlier phases are picked up from the implementation phase which after testing each unit is integrated into a module or system for various tests like stress test, load test, etc. The test environment undergoes constant software testing to determine if there is any flow or flaws in the design or code. Testing is performed to maintain the stability and feasibility of the software so that the customer is not faced with glitches or bugs during production. In this phase, the entire system is thoroughly tested for errors and failures after implementation.
System tests consist of three different types of activities that can be specified below:
- Alpha (α)-Test:The tests performed by the development team.
- Beta (b)-Test:It's the tests done by a friendly team of customers and users.
- acceptance test:It is done afterAlpha-Tests und Beta-Tests. This happens after delivery by the customer. After the customer has performed tests, a decision is made whether to accept or reject this software. This is the phase in which errors are debugged.
6. System Provisioning / Operation
Once the non-functional, functional, alpha and beta tests are completed, the software product is deployed to the user's or customer's system or released to the market. The deployment phase includes installation, migration and support of the complete system in the user or customer environment.
It is the last but most important stage in the waterfall workflow model. This step occurs immediately after installation and includes making the appropriate change to the product or system, or improving, changing or modifying attributes related to performance issues related to the system. Its main task is to improve the performance of the system with the result of software output with maximum accuracy.
These changes made during the maintenance phase mainly relate to initiated changes to be made by the customer or users after the installation and testing phase, including bugs such as bugs revealed during live use of the system or requests made by customers. In this way, the customer receives timely and scheduled maintenance and support for the developed product. You will be amazed that the effort in the design and development phase of the software product is only 60% compared to the effort in the maintenance phase.
There are three types of maintenance given below:
- Corrective Maintenance:During the design and development phase, some errors are not discovered; they are only taken into account if the customer uses them. This is corrective maintenance only; H. fixing problems or bugs that were not discovered during the development phase.
- Perfect maintenance:This maintenance is carried out at the customer's request in order to expand and improve the functionalities of the system or the software.
- Adaptive maintenance:The maintenance required to change the system environment is usually needed to port the existing system to a new climate, computer or system, or possibly with a new operating system. This phase is too important as it leads to better system performance.
So, in the above discussion, we know well each phase of the waterfall model with complete specifications. So we can say that the waterfall model is very important in the software field compared to the mechanical industry because each phase has its own importance, resulting in a more productive and stable software.
Pros and cons of the waterfall model
Below are the advantages and disadvantages:
- It allows for departmental division and control.
- A timeline with deadlines can be set for each development phase, and a product can progress through the phases of the development process model in sequence.
- As it goes through stages that are easy to understand and explain, it overcomes many problems and makes it very easy to use.
- Due to the rigidity of the workflow model, it is very easy to manage as each stage in the waterfall model has specific review and delivery processes.
- The waterfall model works well for smaller projects where the requirements are very well understood.
- The schedule can be set with deadlines for each development phase, and a product can cycle through the phases of the development process model.
- Clearly defined stages.
- Well understood milestones.
- Easy to arrange tasks.
- Process and results are well documented.
- Reinforces good habits: define-before-design.
- The model works well for smaller projects and projects where the requirements are well understood.
- Not a good model for complex and object-oriented projects.
- Not suitable for projects with a medium to high risk of change.
- It is difficult to estimate the time and cost involved in each phase of the development process.
- Not a good model for complex and object-oriented projects.
- Working software is not produced until late in the life cycle.
- Cannot meet changing needs.
- It's not easy to measure progress within phases.
- High level of risk and uncertainty.
- Bad model for long and ongoing projects.
- Adjusting the scope during the lifecycle can kill a project.
- No feedback path.
- No phase overlap.
- Change requests can only be considered with difficulty.
- Risk and uncertainty are high with this process model.
Where to use the waterfall model?
Now that we've circled all the scenarios, we come to a point where we want to know where we can use the waterfall model.
- In a defense project, the waterfall model is mainly used. The requirement is clear because it analyzes them well before moving to the development phase.
- This can also be used in migration projects where the requirements are just the same platform or the languages may vary/change.
So, overall, we can say that waterfall model is most suitable for small software development projects compared to large projects because design, development and implementation in small project is easier when working on waterfall model. Finally, in this model, all previous phases must be completed when moving to the coming phases. So, for large projects, the problems and errors are common because it is a large model. The testing phase continues every time it is implemented by the waterfall model, resulting in less optimization and accuracy of the software.
This is a guide to the waterfall model. Here we have discussed the phases, pros and cons of the waterfall model. You can also check out our other recommended articles to learn more –
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The waterfall model is a sequential design process in which progress is seen as flowing steadily downwards (like a waterfall) through the phases of Conception, Initiation, Analysis, Design, Construction, Testing, Production/Implementation, and Maintenance.What are the different phases of waterfall model in detail also mention the various limitations of waterfall model? ›
Winston Royce introduced the Waterfall Model in 1970. This model has five phases: Requirements analysis and specification, design, implementation, and unit testing, integration and system testing, and operation and maintenance. The steps always follow in this order and do not overlap.What is the waterfall model and explain the advantage of it? ›
Waterfall relies on teams following a sequence of steps and never moving forward until the previous phase has been completed. This structure is suited to smaller projects with deliverables that are easy to define from the start.What are the disadvantages of waterfall model with explanation? ›
The disadvantage of waterfall development is that it does not allow much reflection or revision. Once an application is in the testing stage, it is very difficult to go back and change something that was not well-documented or thought upon in the concept stage.What is a disadvantage to using the waterfall approach? ›
Disadvantages of the waterfall method
The client's limited visibility throughout the project might result in the deliverables not meeting their expectations. Changes can be difficult and costly to implement and the team needs to review the entire project from the beginning, considering that phases are interconnected.
Maintenance is the final phase in waterfall model.What is waterfall model explain it in detail? ›
The Waterfall methodology — also known as the Waterfall model — is a sequential development process that flows like a waterfall through all phases of a project (analysis, design, development, and testing, for example), with each phase completely wrapping up before the next phase begins.What is the second phase of the waterfall model? ›
Design. After the first phase is completed and verified, it is the next most important phase to be studied as it is used for system design. It helps in specifying software and hardware requirements for product design. It also helps in the overall architecture of the system design.What are the three critical stages in waterfall model known as? ›
Design: resulting in the software architecture. Coding: the development, proving, and integration of software. Testing: the systematic discovery and debugging of defects. Operations: the installation, migration, support, and maintenance of complete systems.Which phase of waterfall model takes maximum effort? ›
testing phase consumes the maximum effort.
The steps include Requirements Determination, Design, Implementation, Verification, and Maintenance.What are the advantages and disadvantages of both the waterfall and agile system development processes? ›
Agile projects are typically cheaper and can be delivered quickly. They offer greater flexibility, but also produce less predictable results due to the uncertainty and unclear nature of many of the project characteristics. Waterfall projects are typically more expensive and take longer to deliver.What is the advantage of water fall? ›
Waterfalls provide soothing sights and sounds that help you relax and de-stress in today's busy world. Lower your blood pressure and improve your physical and mental health as you prop your feet up and enjoy the therapeutic effects of Mother Nature.What are the problems in waterfall model? ›
Disadvantages of waterfall model
Once an application is in the testing stage, it is very difficult to go back and change something that was not well-thought out in the concept stage. No working software is produced until late during the life cycle. High amounts of risk and uncertainty.
The disadvantages of the waterfall methodology are that: It is often difficult, particularly in BI, to get complete business requirements up front in a project, because business people have not really thought through in detail what they need, and business requirements can change during the project.What are some of the challenges with waterfall methods that prompted the? ›
- INFERIOR QUALITY. The development team is forced to cut testing short, which makes the project suffer in the long run.
- BAD VISIBILITY. ...
- LARGE RISK. ...
- HOW TO HANDLE PROJECTS WHEN THEY OVERRUN THE INITIAL ESTIMATES? ...
- Cost Overrun. ...
- Time Overruns. ...
- The Iron Triangle of Software Development.
The deployment phase involves making the software live in the production/real environment after it tested for its tested thoroughly in the previous phase.What is testing phase in waterfall model? ›
In Waterfall, the testing phase happens after the building phase. This means clients must be concise and clear on requirements before development begins. Once the project begins, there cannot be any changes made.What is the first stage of the waterfall method? ›
This is the initial planning process in which the team gathers as much information as possible to ensure a successful project. Because tasks in the waterfall method are dependent on previous steps, it requires a lot of forethought.
Waterfall model is based on three main principles: low customer involvement, strong documentation, and sequential structure.
The following is a list of waterfalls by type. Plunge: Water descends vertically, losing contact with the bedrock surface. Horsetail: Descending water maintains some contact with bedrock. Cataract: A large, powerful waterfall.What are the major elements of waterfall development? ›
Waterfall development follows the phases of the life cycle in sequence (planning, analysis, design, and implementation). Each phase is thoroughly documented and approval is required before proceeding to the subsequent phase.Which phase is the longest phase of waterfall methodology and why? ›
Explanation: Development phase is the longest phase in the waterfall model.What type of project is the waterfall process best suited for? ›
Waterfall is a linear project progression, so it's best suited for projects with a defined end goal. If a project owner has a clear and specific vision of an app, for example, and is confident it will not change throughout the project development, Waterfall methodologies could be a good system to follow.How risk is managed in waterfall model? ›
Waterfall and risk management
The risks in Waterfall are also managed with the help of charts. The risk chart begins when the risk is detected. After that, the managers follow its development. If the risk develops along with the project, its line in the chart goes up.
- The process is not as flexible as agile approaches.
- It's difficult to foresee roadblocks and dependencies that could delay work.
- Work is not always evenly spread out across the team.
- Project overload is possible.
- Short-lived teams may ignore conflict for the sake of getting to the end of the project.
- Less predictable. The flexibility at the core of the Agile method also means a much lower degree of predictability. ...
- More time and commitment. ...
- Greater demands on developers and clients. ...
- Lack of necessary documentation. ...
- Projects easily fall off track.
|This model is less costly compared to others||Rectifying a problem in one unit requires correction in all the units and consumes a lot of time|
|A customer can respond to each building|
|Errors are easy to be identified|
The Failings of Waterfall
Waterfall uses the theory that what you want at the beginning is what you get at the end so there is little, if any room, for significant changes in direction. Being an inflexible model which does not provide for feedback, it is difficult to highlight new requirements and thus change course.
- Flexibility and Adaptivity. An Agile/Scrum approach is best-suited for a relatively uncertain environment. ...
- Creativity and Innovation. ...
- Time-to-Market. ...
- Lower Costs. ...
- Improved Quality. ...
- Customer Satisfaction. ...
- Employee Satisfaction. ...
- Organizational Synergy.
Perhaps one of the biggest advantages of the waterfall model is its clear and precise structure, which lays down the role that you and your associates need to perform at every phase of the project. Such clarity is crucial when planning and executing complex projects as without it, the project can easily get muddled.What are the advantages and disadvantages of Agile and Scrum? ›
- Scrum can help teams complete project deliverables quickly and efficiently.
- Scrum ensures effective use of time and money.
- Large projects are divided into easily manageable sprints.
- Developments are coded and tested during the sprint review.
Agile and Waterfall are two popular methods for organizing projects. Waterfall is a more traditional approach to project management, involving a linear flow. Agile, on the other hand, embraces an iterative process. Waterfall is best for projects with concrete timelines and well-defined deliverables.What is the difference between Agile and Waterfall? ›
The key difference between Agile vs. Waterfall is that Waterfall breaks down software development into isolated phases that flow into each other, while Agile advocates iterative development cycles in which multiple lifecycle phases can run in parallel.What is the disadvantage of process model? ›
The major downside of process modelling is the risk of over analysis. Second, although vendor-supplied reference models may not be used much in implementation projects, process models themselves are still valuable for developing shared understandings of processes and planning software implementation projects.What are the disadvantages of using models? ›
- Mistakes may be made in the programming or rules of the simulation or model.
- The cost of a simulation model can be high.
- The cost of running several different simulations may be high.
- Time may be needed to make sense of the results.
- Potential defects are spotted and dealt with early.
- Functional prototypes are developed early in the project life cycle.
- Less time is spent on documenting and more on designing.
- Progress is easily measured.
- Changes to project scope are less costly and easier to implement.