What is Waterfall, so called the cascade model?

06.08.2020 Angelika Siczek
what is waterfall aka cascade model

The cascade model has become a permanent feature of many companies, not necessarily only in the IT industry. It is the most popular and used method of project management and it is not surprising why, once you understand how simple and effective this system is.


What is the waterfall model?

The waterfall model is a classic system which, as the name suggests, is based on the series of principles. Each subsequent design phase follows one after the other. Each of them is subject to separate tests and usability checks. If a modification or rebuilding is required, this can be done on the part in question and among the people responsible for that part. Perform as many iterations as needed to achieve the goal.


This method is used quite widely outside the IT industry. It is used in construction, production and other industries where there is repetitive design work. However, in the Waterfall methodology we are dealing with an iterative cascade model which has some slight differences from the classical method.


There are eight phases in the general model that must be completed one after the other. First, the theory, that is, the concept phase. Very important is a good planning. It will save you from reworking or starting all over again. The work begins as soon as the theoretical framework is established. Analyzing, designing and building, in exactly this order, is work on creating the application itself. Later, tests are carried out to spot errors. Implementation of the application takes place after the project in the production phase is completed. After the premiere, it’s time to handle the finished product.


What are the most important features of Waterfall?

In Waterfall, the most important thing is a detailed plan that creates sequences of task execution. Their effect is to be the final solution. This model assumes strict adherence to time frames, i.e. deadlines. Documentation of all activities is also prepared. The general assumption is that tasks are carried out sequentially, without exceptions. It is about completing individual tasks in the allotted time to control costs and not compromise the success of the entire project.


The downside is some limitations. If you need to make a modification or change, go back in progress. There is a lack of flexibility here, as you also cannot proceed without completing the previous phase. However, if the tasks are performed as intended and reliably, each participant will quickly notice that the model is suitable for many environments, and that it is clear and easy to use.


How was the cascade model created?

The waterfall model, which Waterfall also comes from, is simple but battle-hardened. Its genesis dates back to the middle of the previous century – the times of industrial production. This model was described by Winston Royce in “Managing the Large Software System Development Process.” The creator himself had doubts about this method and guessed its unreliability. He called it “risky and troublemaker.” However, it quickly proved its advantages in the field of programming.


What is the Waterfall model?

The Wartefall model has certain rigid characteristics that impose the way of working on the whole team and determine the type of cooperation with the client. First of all, it sets out a few non-negotiable steps that should not be changed if the venture is to be successful. This model is a guarantee of success because it is used by so many companies for a reason. Tasks are arranged according to a strictly defined schedule.


Does Waterfall have disadvantages?

The established sequence of tasks may make the course of the project to some extent difficult and extend it, because you cannot proceed to the next stage without ending the current one. If, for example, a client has some suggestions or wants to introduce unforeseen changes, the team has to start over or rebuild a given stage. One thing is for sure – the further work cannot be started. This, of course, increases costs and extends lead times. This can make the whole project successful. However, if you get things right, a skilled development team shouldn’t have any problems.


Tests are another problem of this type of project. They can only be carried out after the project is completed. Although it introduces some order to the work on the application, it may mean additional work time. Writing the code in the dark will certainly generate more defects, which the testers will then have to catch and remove in the last phase.


Probably the biggest disadvantage of Waterfall and the feature that determines the scope of projects on which this model can be used is the type of cooperation with the client. If he does not define his requirements in the first phase of the project, it may turn out that his later changes will not be implemented. This means either cooperation on a predefined scheme, preferably already tested, or a reliable and time-consuming project planning process. If these guidelines are not followed, app launch may be significantly delayed.


What are the advantages of the cascade model?

The Waterfall model has its advantages which, under certain conditions, speak in favor of it. When using this method, work and the entire project should be well planned. The more detailed the descriptions, the better. Technical details of the most complex elements will be of great help in further development work. It is about good knowledge of the purpose, application and customer needs. Detailed documentation is created during the planning process, which will later be used by everyone involved in the project. This will certainly help in its implementation.


Concrete planning in advance and creating a clear project framework means client confidence in the result. There is no room for uncertainty or understatement here. As long as the plan is reliably implemented, the initial concept should completely coincide with the finished product. A similar peace of mind will bring the investor a predetermined schedule and project valuation. The plan will prevent costly deviations from the assumptions and will prevent the investor’s participation in the implementation from being so large. He will get a predefined application that meets the agreed requirements.


An additional advantage of the Waterfall model is the lack of misunderstandings. A strict plan and documentation establish a work rhythm in which there is no longer any room for breaks to establish details. This will provide the team with a certain comfort of work and the awareness that the requirements addressed to them are predetermined, without blind turns and surprises. Using documentation on the basis of a comprehensive plan also means a smooth transfer of parts of the project to a subcontractor or the introduction of a new specialist, without transferring the completion date.



It may seem that Waterfall is not a perfect model. However, it has some strict assumptions that make it a perfect solution for many development projects. A predetermined formula does not exclude creative input at all. It just has to happen early in the project. If a cascade model fits your scope of work, you don’t have to think twice. It serves the client, employees and the project itself. An experienced team will appreciate this way of working because it generates less stressful situations and allows you to work smoothly and without disruptions.

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