We have two popular approaches to complete any project One is Waterfall Models and Another is Agile.
SDLC means Software Development Life Cycle and has many patterns like the waterfall model and the spiral model.
The waterfall is the most popular model in Traditional techniques.
But nowadays Agile techniques are the main reason for quick and quality deliveries.
Scrum is an Agile method. Two are quite different in behavior. Each has its own benefits and drawbacks.
We are going to study the contrast between agile and waterfall methodologies.
Let’s understand in detail:
What is Agile?
It’s an incremental approach to deliver and develop software in a quick manner.
The whole project is divided into small stories.
It is a time-boxed method and frequent deliveries and revisions are very usual.
It is based on communication between the client and the development team.
An agile method is focused on delivery rather than the hierarchy in a team.
Each member of an Agile team has a very important role.
In this process, every story is a bunch of design, development, testing, and deployment.
It breaks the project development into Sprints that are deliverable in two weeks.
The analysis is done after the completion of sprints.
There is no need to project managers, team members can manage the project at their level.
What is the waterfall model?
This a sequential and rigid model.
The whole development process is going through each phase and after the end of the last phase, we get the deliverables.
We can say that part of the project is completely developed.
We need to complete each phase to deliver the product.
We can add changes while development and cant test before completion of the project.
What is good in Agile?
- It is process-oriented.
- Continuous communication and self-motivated agile team.
- Quality is maintained while quick development.
- It is an incremental process.
- Very flexible and can easily implement the changes while developing modules.
- Good for large projects.
- One of the biggest advantages of the agile model is its great adaptability. Adaptability means ‘responding to change’. Agile is very flexible in dealing with the changes in the customer priorities and needs.
- Allows to constantly re-prioritize and refine the overall product backlog without affecting the current iteration in which the team is focused on delivering the (Minimum Viable Product) MVP. The changes can be planned for the next iteration, therefore offering an opportunity to bring in the changes within a few weeks only.
- Agile methodology offers a great degree of stakeholder engagement. The project and the client team meet before, during and after each sprint. As the customer is constantly involved throughout the project or a final result, there are more opportunities for the team to clearly understand the customer’s vision.
- The working software is delivered early and frequently. This increases the stakeholder’s trust in the team and encourages the team to stay highly committed to the project.
- This model gives transparency. Both the team and the stakeholders know well about what is happening. The client can see the progress of the work.
- Fixed schedule sprints of one to four weeks allow for early and predictable delivery. New features are released frequently and quickly in a time-boxed manner.
- Agile is customer-centric. It does not just deliver the functionality but also focuses on delivering the feature that is of some value to the user. Each user story has business-focused acceptance criteria.
- Valuable customer feedback is gained early in the project and the changes to the product can be made as required.
- The focus is on business value. It first delivers what is most important to the client.
- Improves the quality of deliverables. Unlike waterfall, testing is continuously and frequently done in an agile project and that, in turn, helps in detecting and fixing the issues early.
- Agile supports TDD (Test Driven Development) approach which provides enough time to create unit tests for the features that are going to be released through MVP.
- Also, by producing frequent builds, any misalignment with the customer requirements also be detected and fixed early.
- As we get immediate user feedback after each MVP release, the risk of project failure is low, when you are working in an Agile way.
- Agile promotes teamwork. There is a great interaction, collaboration, harmony, and enthusiasm among the Agile team members.
- The schedule and cost estimates of each sprint are communicated to the client prior to the start of the sprint. This improves decision making as the user can understand the cost of each feature and prioritize accordingly.
- In an agile project, there is room for continuous improvement. Lessons learned from the past sprints can be applied in the next (upcoming) sprints.
What is Bad in Agile?
- It is only useful for large scale projects.
- The standups are headed by an expert who can decide the priority and can take decisions on a daily basis.
- Since its a modular development so a little distraction or misunderstanding can lead the project to off-track easily.
- It is often seen that Agile teams have a tendency to neglect documentation. This is because the Agile manifesto more focuses on working software than the comprehensive documentation. However, the teams should maintain the right balance between the documentation and code.
- As it requires a high degree of customer involvement, it can sometimes be problematic for customers who do not have much time and interest to participate in the project.
- It does not work well if the team is lacking commitment and dedication. Waterfall requires involvement, where Agile requires commitment.
- · If the initial architecture and design are weak, then frequent refactoring is required.
- When we compared to the waterfall, Agile is difficult to practice. The team members must be well versed in Agile concepts. It requires a lot of discipline in doing the work and commitment to practice Agile.
- Due to re-prioritization, it is less predictable than what will be delivered at the end of the sprint.
- Due to time-boxed delivery and frequent re-prioritization, there are chances for a few features to not get delivered in the allocated timeline. This leads to additional sprints and additional costs. This can also make a problem to the nebulous timelines.
- Lack of structure when compared to the waterfall, it demands self-discipline, highly proficient and cross-skilled teams. Without this, the project can really be a difficult and challenging one.
- Availability is less of a blueprint of the final deliverable.
- Sometimes the external stakeholder cannot resist following the Agile approach. In such cases, the education and the training about Agile are required to a wide audience.
What is good in the waterfall model?
- Well documented and easily understandable.
- Easy to map the dependencies.
- Faster delivery and suitable for small scale projects.
- Forward & backward planning and implementation is easy.
- The waterfall model is simple to use and easy to understand. It does not require any special training for project managers or employees. It has an easy learning curve.
- Being rigid in the nature, it is easy to manage the waterfall cycle. Each phase has a review process and fixed deliverables.
- Less complexity as the phases does not overlap. Phases are followed one after another. It uses a clear structure when compared to other software development methodologies. The project goes through fixed sequential steps, starting from the requirement gathering and finally lands at maintenance.
- Due to phased development, discipline is enforced, and timescales can be kept easily.
- Works well for small projects where we have fixed and crystal-clear requirements.
- Processes and results are well-documented.
- Arranging tasks is easy.
- It is easy to measure the progress as the start and endpoints of each phase are predetermined.
- There are almost no changes in the requirements throughout the project, hence the tasks remain stable for the developers. Also, it is very easy for any new developer to quickly learn and start the work.
- There are no financial surprises. Once the requirements are fixed or gather, then the final cost can be calculated before starting the development.
- Caters for a sequential funding model.
- Its detailed design makes the final expected outcome very clear to everyone.
- The functional requirement specification documented in the requirement gathering phase gives enough details to the testers to design the test scenarios and the test cases. Therefore, the testing process becomes easy in the waterfall model.
What is bad in the Waterfall Model?
- Not good for large projects.
- Very difficult to adapt changes while development.
- Only we can move to the next step after completing the previous one. So a very rigid process.
- As all the requirements must be clearly and known before starting the development, it’s delays the project.
- Requires extensive research as per the user needs.
- At the initial phase of the project, it is challenging for the customer is clearly define and conceptualize their requirements in the form of functional specifications. Hence, there is a high possibility for them, to change their minds after seeing the end product. This change can also occur due to a market influence or business plan. Low flexibility in this model makes it very difficult to accommodate any such changes, especially when the product needs to be re-engineered to a large extent.
- No working model is produced until the later stage during the waterfall lifecycle.
- Slow delivery times. The customer is not able to see the product until it is fully completed.
- The customer has no opportunity to get familiar with the system in advance. The waterfall model is more of an internal process and keeps the end-user excluded.
- The client is not informed well about the health of the project.
- Deadlines can be missed if strict management and regular monitoring are not kept.
- There is no room for changes even it is visible during the development as the product is not going to cater to the market requirement.
- Delays testing until after completion. Also, large revisions is very very costly at this point.
- High risk and uncertainty are involved in the waterfall model as there is too much room for issues to remain unnoticed until the project comes near to completion.
- Not a suitable model for long, complex and ongoing projects.
- It is difficult to measure the progress within each phase.
So we the above study demonstrates Agile vs, Waterfall.
Agile and Waterfall are quite different in approaches and both are the methodology of different times.
Agile is modern and in a trend whereas waterfall methodologies are the most popular techniques to develop a project.
They have their own usability and advantages.
This representation of agile vs waterfall project management will make you understand their importance at their places.