Blending Agile and Waterfall: Seamless Integration

Agile and Waterfall are the two most common Software Development Life Cycle (SDLC) methodologies followed by organisations involved in Software Development. While Waterfall is a traditional and simple model with a linear flow, Agile is iterative and adaptable. While both models have unique use cases, imagine a Hybrid model with the features of both. This is where Blending Agile and Waterfall Models can help.   

According to Statista, 37% of respondents use the Agile model, while 26% use the Waterfall model for Software Development. If you want to reap the benefits of both these models, this blog might help you immensely. So, read this blog toDiscover how Blending Agile and Waterfall methodologies can lead to a more efficient and flexible Project Management approach. 

Table of Contents

1) What is Agile model? 

2) What is Waterfall model? 

3) Agile and Waterfall: What are the differences?

4) Blending Agile and Waterfall 

5) Challenges in creating a Hybrid model 

6) Conclusion 

What is Agile model?

Agile methodology is an SDLC model which simultaneously performs development and testing procedures. It divides a project into smaller components, with each part being treated as an increment. Agile methodology allows and encourages self-organisation among the team members and encourages communication between customers and Developers.   

The Agile model was initially published in the year 2001. This model contains four core values which include the following:

a) Individuals and interactions over processes and tools 

b) Working software over comprehensive documentation 

c) Customer collaboration over contract negotiation 

d) Responding to change over following a plan 

The Agile model allows you to adapt to changes in project requirements and, thus, shift priorities related to the project. This model, however, can become derailed and deviate from the original goal very quickly if the Agile Project Manager fails to understand the project's goal.   

Agile methodology is beneficial due to its iterative and collaborative nature. This method involves the client in the development process and allows them to share constant feedback. The client verifies every iteration in the Agile framework to verify if the product is heading the way they envisioned the final product.   

Every feature in Agile gets verified while it is still in creation, allowing for easier changes if necessary. This means every feature added to the project is constantly verified through regression testing, reducing the chances of failure. Therefore, this model can be adaptable to changes, even if the end users request the changes.   

The Agile framework does not focus on detailed predictive planning, as one of its key principles acknowledges that change is inevitable. As a developer, if you were to work with an Agile framework, you’ll notice that documentation eventually becomes outdated. The documented set of requirements can become completely irrelevant as the requirements change.   

Some common examples of Agile methodology applications include Kanban, Scrum, Extreme Programming, and Lean Software Development.
 

 

What is the Waterfall model?

The Waterfall methodology is considered one of the most basic and traditional SDLC models and is commonly used across organisations. This model is used when the project is relatively small, and its requirements are easily understood. The model gets its name from its diagrammatic representation, which resembles multiple Waterfalls.  

The Waterfall model was first introduced in 1970, making it the first SDLC model. Due to the linear nature of this model, it can be challenging to go back to a previous stage of the development process. As a result, a new phase in this model can only begin when the last phase has ended completely. Here's what the stages of a Waterfall model look like:
 

Each phase in the Waterfall model is focused on one task entirely, with well-documented specifications, requirements and architecture. This also extends to the testing phase, which cannot be done parallel to the development phase. Each development phase of this model goes through a carefully designed detailed test at the end. Since the testing phase in Waterfall doesn’t occur until previous phases are completed, the Quality Analysis (QA) team can dedicate their time to designing test cases while the development phases are in process.   

The Waterfall model prioritises documenting all the details, minimising the potential for misunderstanding. As a result, any new team member has an easy time following the records and keeping up with their more experienced peers. Any possibility of the work being derailed due to lack of information is close to zero in Waterfall.   

Waterfall’s documents do not just benefit the ongoing project but help with future tasks as well. The records of previous tasks serve as a guide, which developers use to reduce the time taken in the planning phase. These documents specify the details and scope of the project. 

The Waterfall model has eight phases that include: 

a) Conception 

b) Initiation 

c) Analysis 

d) Design 

e) Construction 

f) Testing 

g) Implementation 

h) Maintenance 

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Agile and Waterfall: What are the differences?

Agile and Waterfall's models are widely popular in the development process across organisations. However, there are fundamental differences between both. Both models approach tasks like development, deployment, and testing phases differently. Here are some core differences between both Agile and Waterfall: 

Structure: Agile uses timeboxing method, which dedicates a certain amount of work to a time frame referred to as Sprint. The Waterfall model separates the project into stages focusing on tasks such as development and deployment. Agile models can adapt to the changing priorities of the project, while Waterfall uses an unchanging sequential methodology.  

Flexibility: Agile is a relatively more versatile model than Waterfall, where the latter model is considered rigid. Due to this, Agile may use a phase multiple times through the Development Life Cycle, while Waterfall only goes through a stage once.  

Verification: Agile model frequently uses testing to keep the quality of work done in check, which rarely happens in the Waterfall model. The Waterfall model solely focuses on completing a project where Agile takes extra measures to meet customer expectations.  

Team size: Waterfall has limited scope for team members to coordinate and synchronise their work. Agile methodology focuses greatly on collaboration between team members, placing a high value on team members’ ability to communicate with each other.

Now let’s explore the differences between Agile and Waterfall by comparing their advantages and disadvantages.

Advantages and disadvantages of Agile Methodology 

Here, you will explore the advantages and disadvantages of Agile Methodology: 

a) Advantages of Agile methodology

1) Client involvement and satisfaction: The client is an active participant in the Agile project and can provide feedback and suggestions to adjust the product and its features according to their needs and preferences. The client also validates the product at the end of each iteration. This ensures that there are no discrepancies between the requirements and the implementation. 

2) Efficient testing and integration: Testing is done concurrently with development in each Sprint, which improves the efficiency and quality of the testing process. Each feature is fully tested and integrated with the rest of the system. 

3) Flexible and adaptive planning: Agile methodology follows an adaptive planning approach, which allows for changes and modifications in the scope, schedule, and budget of the project as the situation demands. Change requests are easier to implement, as there is enough space and time to accommodate them in the next iteration. 

4) Minimal and essential documentation: Agile supports minimal and essential documentation, which focuses on the key aspects and outcomes of the project. This saves time and resources and allows for more focus on designing and executing test cases. 

5) Scope creep prevention: Agile methodology allows for frequent monitoring and communication by the client, which helps prevent scope creep. Scope creep can result in increased costs, delays, and risks for the project.

b) Disadvantages of Agile methodology  

1) Experience and decision-making skills: Agile methodology requires a high level of experience and quick decision-making skills, as it involves dealing with frequent and unpredictable changes. DevOps professionals are required to evaluate and prioritise the changes and decide which ones to accept and which ones to defer for the next sprint. 

2) Understanding and commitment: Agile methodology does not work well if the client or the team does not understand or commit to the Agile principles and practices. Agile is a fast-paced and collaborative environment which requires constant communication, feedback, and cooperation among the stakeholders. Agile is considered a risk for a team that lacks experience or motivation.

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Waterfall Methodology

Here, you will explore the advantages and disadvantages of Waterfall Methodology: 

a) Advantages of Waterfall methodology

1) Clear and stable requirements: The Waterfall methodology is suitable for projects that have well-defined and fixed requirements which do not change frequently or drastically. It follows a linear and sequential model, where each phase produces a quality deliverable. 

2) Comprehensive documentation: The Waterfall methodology emphasises creating and maintaining detailed documentation, such as requirements, functional specification, technical specification, and technical architecture. These documents serve as the basis and reference for the project and are considered to be some of the best practices in Waterfall methodology. 

3) Ample time for testing: The QA team gets enough time to understand the requirements and create elaborate test cases which cover all the aspects and scenarios of the project. A comprehensive test case enables QA to execute the test case accurately and unambiguously. 

4) Effective knowledge transfer: The Waterfall model can facilitate efficient knowledge transfer among team members who are located in different places by investing sufficient time and effort in understanding the requirements and the documentation. 

b) Disadvantages of Waterfall methodology 

1) Less time for test execution: The testing teams often get a shorter time frame to complete test execution, as more time is spent during the initial stages for extensive documentation. This can affect the quality and efficiency of the testing process, as well as the delivery of the project. 

2) Unexpected delays and changes: There can be unforeseen delays and changes in the project if the requirements are not clear or complete at the beginning of the project, which is often the case in larger and more complex projects. Only a rough outline of the requirement may be available initially, and some requirements may only emerge after some trial and error. 

3) High cost of fixing bugs: A bug that is identified at a later stage of the project can cost up to 60 per cent more to fix, as compared to its cost when identified at an earlier stage. This is because the bug may affect the entire system and may require significant changes and rework. The Waterfall methodology does not test the system until the end of the project, which increases the risk and the impact of bugs.

Comparing the pros and cons of each methodology may lead one to consider a solution that combines the benefits of both according to the needs of the project. Waterfall methodology could adopt some of the flexibility and agility of Agile methodology, while Agile could benefit from some of the structure and discipline of Waterfall methodology.

Blending Agile and Waterfall 

The personal preferences of Software Engineers can often lead to arguments over which SDLC model is superior. However, the truth is that both Waterfall and Agile models have their respective uses. Instead of wondering which model suits your project better, why not have a model that brings the best of both? This is where blending these two models into a hybrid model can play a significant role. Here's how you can benefit from this amalgamation:

Hybrid model: Agifall 

When Agile and Waterfall models are blended, the resulting model can be called the Agifall model. The Vancouver Digital Project Managers Meetup Group created the Agifall model. This model combines the features of both models by implementing Agile methodologies into the Waterfall model.  

The Agifall model benefits project teams with higher speed, lower cost, and greater quality than they would get using either of the models individually. The Agifall model has the flexibility of Agile blended with the principles of Waterfall, as it doesn't wait for a phase to end before working on another one. For example, while usually, the development phase can't start until the planning phase is over, Agifall allows you to develop certain components while still in the planning phase.  

In the Agifall model, if you clearly understand which components are necessary for the project, you can start working on them during the planning phase. Phases like testing and graphic designing are often done in parallel in the Agifall model. This Agifall model uses quick prototype tools and keeps its planning phase user-centric. 

Hybrid model: Water-scrum-fall 

The Water-scrum-fall model is another hybrid model that combines Waterfall and Agile methodologies. This name is derived from Waterfall and Scrum, as Scrum methodology is based on Agile principles. The development practices in Water-scrum-fall follow the traditional Waterfall method. The initial phase of the Water-scrum-fall model involves gathering requirements, planning future approaches, and deciding the budget. Once the initial phase has progressed enough for the project to have a clear vision, the phase switches to Agile's time-boxed method.  

This allows a team to clearly understand their goal while retaining the ability to improve upon initial plans. The Water-scrum-fall model is frequently used in projects that do not have a well-established goal but require a predetermined budget. A project's budget plays a significant part in its development. This makes stakeholders feel much more secure than the average Agile methodology.  

Additionally, the Water-scrum-fall model follows Agile principles that foster greater understanding between team members. Experienced team members gain the ability to self-organise and take pride in committing to their work. Another common Agile principle and practice involve different team members collaborating while respecting others' views on a common subject.  

Many team members naturally tend to instinctively develop the qualities praised in Agile over time. Using a hybrid model like Water-scrum-fall allows team members to use these qualities well. This allows team members to self-organize and take the initiative toward their work without lacking direction or vision for the project.

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Challenges in creating a Hybrid model  

Waterfall and Agile are often considered two SDLC models on opposite sides of the development model spectrum. While Waterfall rigorously defines and records the details, Agile believes that any documentation can become outdated with time. Where Waterfall carefully plans future tasks, Agile’s process changes continuously as a project progresses. 

Mixing these models poses certain challenges, some of which are as follows: 

Lack of training

Implementing a new development model doesn’t just change how a project is done but also how team members views the said project. A team which has followed the Waterfall model for a significant duration can face difficulties adapting to Agile methodologies. Changing the management model without training the firm's employees can lead to disaster in future.  

A Project Leader experienced with either Waterfall or Agile mode won’t know how to mix these ideologies. It's necessary to train the team members to a degree where they have an equal understanding of Waterfall’s linearity and Agile’s iterative nature.  

Lack of guidance

Agile methodology places a lot of value on communication between the team members. As a result, it is important for the employees who are used to Waterfall’s disconnected culture to be taught the value of collaboration. Agile methodologies such as Scrum have dedicated roles like Scrum Master, whose primary goal is to teach these values to team members.  

In the lack of such guidance and a sudden culture change, team members can feel lost and helpless. This sudden culture change can result in work getting derailed. A Manager or a Team Leader can avoid such issues by taking the time to guide a team properly. Patience plays a huge part in these situations as the maturity of Agile takes time.   

Lack of metric conveyance

The difference between Waterfall and Agile models is not limited to the difference in culture but also in the technicalities, phases and metrics. For example, Agile frequently uses Timeboxing metrics such as sprints, daily meetings and retrospectives. The value of these Agile metrics is often different for metrics in the Waterfall model, such as a data plan or actual time, such as a day.   

The Waterfall is a rigid but easy-to-understand model. As a result, there needs to be an established common ground for metrics to integrate the benefit of a much more complex Agile model. This can be achieved by translating the metrics into a form familiar to employees, and this helps convey the value of metrics better, allowing a hybrid model to mature smoothly. 

Conclusion 

It is crucial to understand that there is no true or correct way to develop software or manage a project. Sometimes, Agile’s iterative nature can help you overcome a lack of vision. There will also be times when Waterfall’s linearity will simplify a development process.    

Blending Agile and Waterfall will allow you to create a Hybrid model that brings you the benefits of both these development models. Hope you have a better understanding of the benefits of a Hybrid model created by combining Agile and Waterfall, as well as the challenges faced while doing so. Thank you for reading. 

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