Waterfall historically originated at the beginning of the last century and in the middle of it was already quite strictly systematized and accordingly used very actively in Western society and especially in the United States. Agile is a newer system coming from Japan and has become quite popular in recent years. To date, according to TrustRadius.com, only 19% of projects use Waterfall, while 81% are for Agile.
Each of the methodologies has its peculiarities, and respectively advantages and disadvantages. Reference: Waterfall or Agile? What methodology to choose for your project, PM.MBA, https://pm.mba/posts/waterfall-vs-agile/
Here is a summary of each:
Waterfall project management
In this approach, the product development process is strictly consistent. It occurs in several distinct phases, each of which has its time range, and these phases necessarily occur one after the other. The phases are:
Initiation: shaping the idea of the product, defining the requirements for it with the help of the client/end-user. Reference: Agile vs Waterfall: The Difference Between Methodologies, by Samantha Rhine, https://www.businesspad.org/agile-vs-waterfall-difference-between-methodologies/
Design: it is decided what the product will look like and what resources will be needed.
Execution: product realization
Testing: product quality check
Completion: putting the product into operation
The Benefits of Waterfall Project Management Practices
He has a clear idea of how the project will go in time, and at the very beginning, it is specified with the client what is expected from the product in question. Reference: “Waterfall vs Agile Project Management practices”, by Jack Martin, 2021, https://agilescrummastertrainingblog.wordpress.com/2021/01/18/waterfall-vs-agile-project-management-practices/
The client is engaged only in the initial phase, which reduces the load from the client significantly
the workloads can be relatively well distributed – the different teams can be involved in certain stages, and the rest of the time to work on other projects. Reference: Agile vs Waterfall Project Management, https://agileprojectmanagement.home.blog/2020/09/01/agile-vs-waterfall-project-management/
documentation for each phase to avoid ambiguities and misunderstandings.
Some exceptional human resources can also be used, in the sense that even less qualified people can perform certain tasks, as they are clearly defined and fragmented into smaller tasks.
During the implementation, the individual tasks could easily be parallelized
the customer participates relatively little (if the first phase is excluded, where he participates very actively in determining the requirements for the product). Reference: Agile vs Waterfall Project Management, https://agileprojectmanagement.home.blog/2020/09/01/agile-vs-waterfall-project-management/
The customer often sees the product at a relatively late stage and it often turns out that his understanding of the product is different. Reference: “Waterfall vs Agile project management methodology”, https://everyonegoesagiletoday.wordpress.com/2021/01/07/waterfall-vs-agile-project-management-methodology/
poor flexibility – because everything is planned at the beginning, changes in the project are difficult and disrupt the planned schedules. In many areas (such as software development) it is difficult to plan all the functionality of the product from the beginning – especially if the area of application of the product is changing very dynamically. Reference: https://wikipedia-lab.org/waterfall-and-incremental-model-in-project-management/
the phenomenon of “last-second testing” is often reached – as the previous phases have often dragged out beyond the schedule, testing is cut to meet the deadline.
The creative initiative is suppressed and bright personal qualities of individual performers may remain ineffectively used
The changing environment and corresponding requirements easily lead to endless projects
This methodology has two main elements – teamwork and time. Instead of getting the finished product at the end, as in Waterfall, where the project is broken down into many smaller pieces (sprints), each taking about a few weeks, each piece is delivered to the customer and the feedback can serve in the next phases. Reference: “Waterfall and Agile project management”, https://scrumandagiletraining.wordpress.com/2021/01/10/waterfall-and-agile-project-management/
The following is typical:
adaptability – something extremely important in today’s dynamic world – the requirements and functionality of the product can be changed relatively easily
customer engagement – all the time the customer has a connection with the project and it is difficult to get a product that does not meet customer requirements
the simplicity of the product, which leads to less development effort Reference: Comparison of Agile, Scrum and Waterfall project management, EduWiki.me, https://eduwiki.me/comparison-of-agile-scrum-and-waterall-project-management/
Teamwork is valued – the team is raised on a pedestal and ways are sought to improve its effectiveness
Time is divided into separate blocks (sprints)
Testing is not a final phase, but part of each block (sprint)
Sustainability – endless projects without any end product are less common.
The advantages of Agile
The advantages of Agile are easily distinguishable from the characteristics of the methodology:
the client is engaged throughout the process. Reference: Agile, Scrum and Waterfall project management, ossalumni.org, https://ossalumni.org/agile-scrum-and-waterfall-project-management/ As a result, the product is often satisfactory to the customer
Flexibility over time – as there are many customer deliveries with different functionalities, they can be prioritized in order of importance and the most important ones can be made first, which will form a basic version of the product that can be implemented and have a reverse connection from her
Adaptability – it is much easier to react to changing conditions and requirements
Greater creative freedom and motivation for expression. Reference: Agile vs Waterfall management methodology, https://www.kosovatimes.net/agile-vs-waterfall-management-methodology/
Disadvantages of Agile methods
Of course, there are drawbacks:
high workload of the client – the client is not always willing to devote so many resources and it often happens that he avoids this responsibility
higher cost and longer development times – overdue development is a common problem in many areas, and since we have many sprints here, the delay in each of them accumulates a large overall delay, respectively development costs
As the team is an essential part of the methodology, good communication, and organization within the team are very important – something that is sometimes a problem.
And last, there is no clear project logic model to follow. Reference: “Project Logic Model (Logical framework approach)”, BVOP.org, 2019, https://bvop.org/posts/project-logic-model-ipm/
Naturally, there are also attempts to combine the two methodologies, deriving their advantages. In general, many companies adopt these methodologies to their needs.
As you can see, both main methodologies have their pros and cons, so some in different situations and companies, one methodology may be better than the other (for example, if you know very well what kind of product you want and want to get it at some point and you do not want to experiment – Waterfall is your method), so you can not easily reject one or the other.