Two project management methods that are incredibly popular yet quite different are Waterfall and Agile. Within these two overarching strategies, there are various subcategories but generally, they follow the same patterns. In this article, we’ll discuss Waterfall vs Agile, the differences, as well as the advantages, and the disadvantages of each of the two project management methodologies.
1. Waterfall vs Agile: The fundamental difference
Waterfall is what can be called a more traditional organizational approach involving a linear step-by-step method, from planning to completion. There are well-defined stages and each stage needs to be completed before the next stage is started. Forward planning is essential, and a lot of time is spent defining the planning stages and requirements before the work begins.
Agile methods follow a more flexible approach, that allows for the development and changes to take place during the process. It breaks the project down into separate tasks that employees work on at the same time. This is an iterative process involving collaboration between teams, management, and client and cross-functional teams.
These are very different approaches but both have their advocates. It is useful to look at the main differences in more detail before deciding which approach will suit your particular business, team, and even project. It is clear that Waterfall suits certain situations better than Agile, and vice versa.
2. The key differences between the Waterfall vs Agile Models
2.1. Planning
- Waterfall
There is no getting away from it planning is absolutely essential in the Waterfall model. It needs to be clear from the start what the requirements are. The plan is then based on the long-term duration of the project and followed in a linear fashion. These requirements need to be well-defined and well documented. The overall success of the project depends on following the plan, in a clear, predictable way and implementing the requirement set out from the start.
- Agile
In short, when it comes to Waterfall vs Agile, Agile is much more agile, because of the nature of its planning. There is of course an overall plan but it is far less detailed. The detailed plans are strictly on a short-term (sprint) basis usually over a couple of weeks to a month. The planning is iterative rather than linear. In this way, projects can adapt and change as the requirements do. Requirements are defined on an ongoing basis with input from the client along the way.
2.2. Roles & Responsibilities
- Waterfall
In a Waterfall project, the roles are pretty much what we have come to expect from a traditionally organized business. There is a hierarchy of management and employee roles. Team members have different roles depending on their level and skillset and with these roles come the traditional responsibilities. Usually, management is responsible for planning, then they pass it on to different teams for the implementation, testing, and maintenance stages. Within these teams, there will typically be team leaders or more senior staff.
- Agile
Agile takes a different view of the organization of roles, although there is some difference depending on which Agile method you are following. There are fewer roles in general and it is a much less hierarchical structure of management. There are ascribed roles that are essential to the Agile method, for example, Scrum roles which are needed. However, once the work goes to the teams then there is much more self-management and responsibility taken on by the team members. The team members have input into the planning and breakdown of tasks as well as input into how these tasks should be carried out. It is a much more collaborative approach. The managers are seen more as facilitators and organizers allowing the workers to get on with the tasks.
2.3. Communication (teams and clients/end-user)
- Waterfall
Waterfall requires less communication throughout the project. Regarding teams, each team is fulfilling its own function for that stage of development and can work as a self-enclosed group before the project passes on to the next stage. As for client communication, of course, this is vitally important in the initial stages but once these are completed and agreed upon there does to need to be much client input at all. Clients will be involved at certain milestones but there is no necessity to be part of the process on a daily or even weekly basis. Then the client and end-user will be involved in the testing and feedback stages after the implementation.
- Agile
Agile needs ongoing communication throughout the length of the project. Teams work in a cross-functional and highly collaborative way. Agile set a great store by its openness of communication and the visibility of what is happening at any particular time. Clients are expected to be heavily involved all the way through the project in a very hands-on way. As such, they can have ongoing input and provide feedback, incorporating changes and additions at each stage for each task if necessary.
2.4. Flexibility/Scope changes
- Waterfall
There is flexibility in the Waterfall model but it’s mainly in the planning stages. At this point, a discussion of requirements, potential changes, and problems needs to be ironed out through negotiation and agreement with the client. Once the project moves on to the next stages Waterfall has difficulty coping with new changes brought in during the project. Changes can be made but the detailed planning that has gone into the project means that any changes can be costly and take a great deal of time. Rather than steering an oil tanker in an ocean, they can change directions but are not the most nimble of creatures.
- Agile
Agile on the other hand has proved so popular because of its ability to change. It is all about new ideas and input. Short-term planning means that changes are not so disruptive. Agile is much more experimental and positively welcomes change. This of course comes at a cost as far as budget and timelines are concerned but that’s part of the deal.
2.5. Progress Measurements
- Waterfall
With Waterfall the plan works as one whole developing slowly but steadily towards a final conclusion. Measuring progress along the way is not easy, although it is obvious when a stage has been completed. Even if a manager or client wants to see the actual progress of some kind it can be difficult to explain as the progress is not often overt and obvious. Team progress is normally reviewed once a week in order to track wherein the stage a team is in, but this will usually involve discussion rather than an actual show.
- Agile
Agile delivers working features as it develops rather than waiting to implement everything as one on final completion. Therefore Agile has something to show, frequently and often. This is fundamental to the Agile model as this forms a base for iteration after feedback. As well as this, Agile incorporates progress meetings and visual progress tracking into its very core.
2.6. Project Delivery
- Waterfall
Waterfall centers around delivering the project in one fell swoop. A single one-off reveals the event. Everything is ready, and here it is. Sometimes known as a Big Bang Event.
- Agile
Agile delivers working features after each Sprint. These can then be worked on until they are absolute to the client’s satisfaction using the recognized iterative method. The final completion involves putting these separate tasks together as one.
2.7. QA/Testing
- Waterfall
Generally, the Waterfall method involves QA and all other forms of testing as a separate stage towards the end of the project. This doesn’t mean, however, that the model can’t incorporate testing during the implementation stage. Much depends on the organization’s ability and wish to customize the Waterfall system they are using.
- Agile
Agile tests and uses quality control throughout the project as a standard. Testing each separate task and working on it until it is satisfactory.
3. Advantages/Disadvantages of Waterfall
3.1. Advantages
- Well documented – used to involve new teams or team members with a minimum of fuss
- Genuine progress from one stage to the next
- Organized and likely to stick to budget and schedule agreements, mainly due to lack of changes
- Ideal for small straightforward project or project updates, upgrades or additions.
- Ideal for projects that have concrete requirements and limitations
- Straightforward, easy to understand system for teams and clients alike
- Logical and routine based
- Good for planning work team who will be involved in the stage -other teams can be used on other projects
- No need for heavy client involvement -the project can be left to take care of itself once in progress.
- Gives a coherent whole project completion, everything is predesigned to fit and work as one
3.2.Disadvantages
- No appropriate if changes are expected through the development
- Planning takes time and requires detail
- High risk – limited client involvement means the client could be in for an unwelcome surprise at reveal time.
- Lack of testing – errors found late can require a lot of work to go back and put right
- Not good for complex projects especially experimental ones
- Not good at responding to market changes during a project
4. Advantages/Disadvantages of Agile
4.1. Advantages
- Adapts well to changes and feedback
- Ongoing testing means swift identification and fixing of errors
- The rapid development of usable features – clients can not only see what they are getting early but can actually use some of it.
- Highly visual progress
- Employee satisfaction -often associated with increased freedom, input, responsibility, and control.
- Works well with remote workers- high-quality online platforms
- Heavy client involvement means a low risk of dissatisfaction
4.2. Disadvantages
- Lack of clear aims, goals, and structure can lead to a chaotic approach
- Increased chance of scope creep
- Costs can spiral as changes are made and timelines are extended
- Lack of documentation can mean it’s difficult to integrate new team members or alternative teams
- Cohesion -as the Agile model uses short individual task-based solutions there can often be a lack of cohesive design and architecture.
- Heavy communication may mean an inefficient way of actually getting the work done.
- Inefficient- employees have to be available to work on one and only one project at a time
5. Waterfall vs Agile: Which System is right for you?
When we talk about Waterfall vs Agile, the question is not which is the best model but which model is the most suitable for you and your team but also for the project you are going to work on. Is it better to work with the more logically intuitive organization of Waterfall or go with the more fluid flexible Agile approach?
In general, Waterfall is commonly applied for projects that are well defined and need limits. This is the case for budgets and deadlines as well as requirements. Clients often feel more comfortable with this system and whilst they have less involvement in the progress of the project, it doesn’t mean they’ll be disappointed. They may even enjoy the excitement and intrigue of the final delivery.
Whilst Agile fits nicely into exciting, constantly developing projects that are dynamic. Clients feel fully involved from start to finish and you can build very strong long-term relationships.
Both systems are proven, both systems can work well within their own limitations. But both systems are models, and you can and should adapt them to suit your needs not force your needs to fit with the system.