26 Oct 2020

Agile vs Waterfall – The Difference Between Methodologies

Introduction: 

A challenging question that project managers tend to ask themselves is which software development model should be employed for more effective results and for a higher success rate in projects.

Popular Project Management Methodologies:

Agile and Waterfall are the two popularly used Project Management methodologies for managing the projects effectively in the software development industry of the modern world. These two methodologies have gained popularity in the past few years due to their success rates. 

The eternal question of Waterfall vs Agile has been debated to determine which development methodology would be best suited for a project. While both have several advantages that could benefit a project and improve the success rate, certain projects may be more successful with either one of the software methodologies.

At the outset, it is essential to know what Waterfall and Agile are, before exploring the differences between them.

What is the Waterfall methodology?

A waterfall model methodology is a linear approach to the development of software which is also known as the Linear Sequential Life Cycle Model. It follows a sequential order which brings in a rigid structure, system, and steps to be followed to move from one phase to another.

The order is usually as follows:

  • Gather the required documents
  • Create a design
  • Code and unit test
  • Perform the system testing and user acceptance testing
  • Fix any bugs or issues
  • Delivery of the finished product

What is an Agile methodology?

Agile methodology is an iterative and team-based method of software development. It is characterized by a practice that promotes continuous iteration of development as well as testing in the process. The testing activities are concurrent in the agile method, which allows for better communication between managers, developers, and customers.

Agile and Waterfall: Differences

The debate of Agile Project Management vs Traditional Project Management can be furthered by looking into the differences between agile and waterfall.

Basis of distinction

Agile

Waterfall

Approach followed The Agile method follows an incremental approach. The waterfall methodology follows a sequential design process.
Flexible nature Highly flexible Quite rigid
Nature of the project Software development is completed as a collection of many projects.

 

Software development is completed as a single project.

 

Testing Testing is performed concurrently. Testing is done after the “Build” phase.
Scope Works well even the scope of the project is unknown.  Works well when the scope of the project is known beforehand. 
Time taken Short term Long term
Planning rate Short term Long term

Through the list of Agile vs Waterfall differences, it is evident that agile methodology can be an efficient option for few while waterfall can be a better option for others. To have a better understanding, let’s have a look at the advantages and disadvantages of both the methodologies and when to use them.

Agile and Waterfall: Advantages 

 

Advantages of the Waterfall Model

In the ongoing debate of Agile Project Management vs Waterfall, these are the benefits of using waterfall as a method.

  • Easy management

The waterfall is one of the easiest models to manage as each phase has defined deliverables and a comprehensive review process.

  • Approach

The process and approach are well-structured and simple to understand, allowing for an easy user interface. It is both easy and simple to understand and use. 

  • Delivery

The project will be delivered faster using the Waterfall model as the schedule will be set for each stage of development. 

  • Documentation

The process, as well as the results, are well-documented as the methodology involves fully documenting a project in advance, including user interface, user stories, and feature variations. 

  • Flexibility

The waterfall is an easily adaptable method for shifting teams. The model is intended to be customized to fit the situation. 

 

Advantages of the Agile Model

While Waterfall has benefits for a project, Agile is more advantageous and provides greater flexibility as explained below.

  • Approach

The Agile approach allows for a better focus and overview, as the team works on making continuous deliveries and evolves throughout the process by gathering feedback from end-users. 

  • Client involvement

It is focused on the client process, which ensures that clients are heavily involved at every stage of the project.  

  • Deliver better results

Agile teams are self-organized and highly motivated, which provides better results as the self-sufficient and cross-functional team works on making continuous deliveries. 

  • Flexible

Highly flexible as it can add different features and can accommodate what is needed for the project at ease. There is a regular adaptation to changing circumstances. 

  • Quality 

Agile software development assures that the quality of the development of the project is consistent. As a result, the final product matches the client’s requirements. 

  • Emphasis on Interaction

There is an emphasis on people and interactions rather than process and tools. Testers, developers, and customers constantly interact with each other which provides a daily cooperation between them. 

 Agile and Waterfall: Limitations

 

Limitations of the Waterfall Model:

There are certain limitations of the waterfall methodology which involves lack of flexibility, ineffectiveness, not suitable for large products, etc. Some of these are explained below. 

  • Limited use for large projects 

The waterfall methodology does not work for a project which is of a large size because it is difficult to move back if any changes required and involve a lot of risks. This is why it is not suitable for complex and large projects where requirement changes frequently. 

  • Ineffective 

Waterfall may be an ineffective method if there are no clear requirements from the start of the project. This is because it does not allow for any change of the defined requirements. 

  • Lack of flexibility 

It can be difficult to make changes in the previous phases of the project using Waterfall. The method lacks flexibility as it leaves no room for unexpected changes or revisions. 

  • Excludes client or end-user

The methodology focuses very little on the end-user as its main purpose is to help internal teams move more efficiently. The client’s valuable feedback is not included with ongoing phase development. 

  • Risk 

The waterfall methodology involves huge risks which occur due to its sequential structure. There can be risks of defects in the final product. 

Agile and Waterfall: When to use

When to use Waterfall

There are certain cases you should consider before adopting a methodology. Here is a handy guide to some scenarios which will help you decide when to use waterfall methodology. 

  • Fixed specifications

In the case where there is a defined, and fixed budget and a strict timeline, the Waterfall methodology will be suitable.

  • A clear vision of a product 

If the vision of the final product is clear and there are definitive steps in mind to be taken to achieve the goals set out, Waterfall will be appropriate. 

  • Low involvement 

In cases where product owner involvement is substantially lower, Waterfall proves to be a great methodology.

  • No scope for change

In the case where clients are not required to have the full ability to change the scope of the project, the Waterfall methodology may be adopted.

  • Regulatory requirements

Waterfall methodology may be employed when the regulatory requirements are strict.

 

When to use Agile:

Agile must be used on bigger and complex projects and where collaboration is highly important. Look at some of the cases when you need to use an agile methodology. 

  • Flexibility 

In the case where there is no fixed budget and timeline for project completion, Agile may be adopted as it is highly flexible.

  • Developing the vision of a product 

Agile may be adopted when the vision of the final product is still being developed and is unclear as it allows for changes to be made.

  • High involvement

Agile is appropriate if the product owner wants to be more hands-on as it allows the product owner to involve deeply in the project.

  • Scope for change

Agile is all about openness to change and a wide scope of flexibility. When clients need to change the project scope, Agile works well as a project management methodology. 

  • Limited regulatory requirements 

In the cases where there is a need for only a few regulatory requirements, Agile methodology may be strongly considered.

Conclusion

Agile and Waterfall are both different methods for software development and have their own set of advantages that are useful for a project to be successful. It may be concluded that both methodologies have their own advantages and disadvantages and suit certain scenarios. It is essential that you know when to use them and make the decision wisely.

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