When should you choose the waterfall model, what are the aspects that will be the most effective in knowing the process? Know more!
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In terms of project management methodologies, the Waterfall Model is the oldest. The Waterfall Modell is the pioneer of the System Development Life Cycle (SDLC) and is broadly used in the software market. As long as technicians work according to some plans, they use this methodology.
What Do We Mean by Waterfall Model?
The Waterfall project management methodology is an example of a sequential model comprised of different phases following one another. The beginning and the end of the phases are set, the end of a phase is a prerequisite for beginning the following phase. In conclusion, this is where the name waterfall comes from, its functionality resembles a waterfall.
Thanks to its logical, formal, and functional rigidity, a Waterfall Model-based project is simple to plan and control. Typically, it is efficient when we know all the professional requirements and are recorded at the beginning of the project. Furthermore, the production of the future product is feasible in accordance with the given technological and professional ties, as well as when the necessary technology is available.
The bottom line is: at the beginning of the project the needs and requirements of the customer are assessed, and the sequential project plan is created with the conditions taken into account.

How to Choose a Waterfall Model?
When to choose a Waterfall Model? What aspects do we need to consider in order to make the procedure as efficient as possible?
1. Industrial Characteristics
In some industries, construction for instance, where the technological requirements define the order of the tasks, the legitimacy of a Waterfall model is obvious. It is equally present in big organizations, where, along with a strategic and long-term functioning, strictly planned yearly development plans and budgets are in order.
2. Schedule
The schedule depends on the plans of the customer is also an important factor. With fixed deadlines, the Waterfall Model guarantees successful planning and doable deadlines.
3. Budget
For the budget, as well as for the schedule, its size determines the deliverable quantities.
4. The Complexity of the Project
There are several factors affecting the complexity of a project, such as organizational complexity, the number of stakeholders and suppliers, or external factors. These can increase the complexity of a project further, in other words, they reduce its calculability. As a result, we need to use the Waterfall Model in an environment as calculable (predictable) as possible.
5. Cooperation with the Customer, Customer Relation
Finally, with a pre-planned, defined project plan and communication plan, in the case of low-intensity communication with the customer (customer load), the waterfall model is the most expedient.

The Trinity of the Project: Budget-Time-Scope
In a waterfall model, the three most important measurable factors for success are: the budget, the required timeframe, and the volumes to deliver. The project’s success depends on the continuous balance of these three.
When the project participants complete a project within the planned timeframe, reaching the scope and within the budget, they typically consider it a successful project. As a result, the quality of the project (often referred to as its fourth factor) will be equally ideal.

The Full Project Lifecycle
The lifecycle of a project according to a classical Waterfall Model comprises of 5 steps:
1. Identifying the Requirements and Determining the Objectives
Firstly, we talk about the brief objectives of a project which the participants have to achieve within a certain timeframe. Basically, an objective can find a solution to an already existing problem, or it can make way to new possibilities in a business. As part of this phase, they will carry out a survey or case study to find out about the feasibility of the project, the profit it would generate, the costs involved and also the potential risks. Certainly, real planning begins after the realization and the approval of the feasibility study.
2. Planning
Secondly, this section develops a detailed project plan, defines the objectives, and breaks down the elementary work packages. (WBS). Planning from top to bottom helps to determine the tasks and missions even in complex and complicated projects. The plan mentioned before contains the tasks, the necessary resources, schedules, expenses, that are the basis of the determined values, the project control. This is when the participants create the project charter, which has a single possible build-up:
Tasks | Schedule Documentation Activity Matrix Task Allocation Form WBS Structure Logical Frame Matrix |
Schedule | Gantt Diagram |
Budget and Resource Planning | Resource and Budget Planning |
Risk Assessment | Probability Matrix Risk Assessment Documentation and Log |
Communication Plan | Communication Strategy and Plan |
3. Realization/Implementation
The success of the realization is greatly dependent on thorough and careful planning. Were all the factors taken into account? Was the correct measurement system created?
This lifecycle phase necessitates the necessary change management, risk management, and intensive communication between the project team, project management, and project board, as well as the customer. This is when real development, testing and installation take place.
4. Verifying- Testing
The quality checks and tests happen after the development of the deliverable product. The specialists carry out the testing, similarly to the development, according to the pre-established requirements and plans, the method and order of execution are fixed. Professionals should fix any bugs discovered during testing before the project closure.
5. Installation- Closure Process
A project can be closed when all the handover and completion documents have been approved. The closing phase involves assigning project members to new projects, finalizing payments, drawing conclusions from the project, moreover handing over the finished product for operation.

Waterfall Models
The Project Management Body of Knowledge (PMBOK® Guide) certainly contains the best-known, most accurate summary of the Waterfall Model used in software development, which is a generally accepted repository of project management methods. Furthermore, the book is a lot more detailed than the methodology itself, -general management knowledge is also included- it is the basis of the CAPM and PMP exams that keep gaining popularity in Hungary.
Summary
In short, we could say that the methodology has many advantages. It has a systematic structure, it is easy to understand, and it is not only useful in software development, but in other areas as well. However, we should not forget about its disadvantages. Think about it, the whole Waterfall Model is based on a linear structure, so the problems that are discovered in a later phase of the project are harder and more time-consuming to resolve. However, these can be resolved easily if an extensive knowledge of the professional application of the methodology is available.