By Eban Escott
The waterfall methodology is a linear approach to software development. Initially, the project requirements are comprehensively scoped out. This is critical in a waterfall project as the final software will reflect the requirements outlined at the beginning. Once completed, the software will be designed, developed, tested and deployed. Each of these is a distinct stage in the process where the previous stage must be completed before the next can begin. This means a project's timeframe is generally longer when using the waterfall methodology but at the end of development you're left with a polished, final version of the software.
In contrast, agile is an iterative approach to software delivery that builds incrementally from the start of the project. It emphasises rapid delivery in complete functional components. These are separated into sprints and prioritised based on their importance. The focus is on the end user. Through early and continuous delivery, agile teams aim to include the customer and end user in the process. For a more detailed analysis of the agile methodology check out this article.
The best fit will depend on your project and personal preference. To ensure you're well informed, we've included the top risks applicable to software projects and the development approach that may mitigate that risk.
In an agile project, both the customer and developer face risks. The customer is likely working off a time and materials pricing model (to be discussed below), meaning the price can fluctuate. The projects timeframe is also uncertain as requirements are susceptible to change. As customer involvement is a prerequisite for agile development, there is a high risk that the response time from the customer may be slow and impede timeframes. However the customer is able to decrease the potential for poor end user engagement as user acceptance tests, which will either validate or modify the project are conducted regularly. The developer also carries risk. Due to the flexibility of an agile project, it's difficult to accurately allocate resources. Development teams may spend more or less time on a project than initially anticipated which may impact future projects in the pipeline.
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In a waterfall project, the risks faced by both parties differ. Fixed pricing and timeframes help create certainty for the customer. However developers risk underquoting a project. As mentioned above, the customer is capable of conducting user acceptance tests and modifying a project when adopting the agile methodology. This is not the case for waterfall development. As a result, customers risk poor end user engagement, or future costs adding/modifying features. The nature of the methodology means that neither party risks scope creep. There are also risks around the sequence of processes. Because testing only occurs after development is completed, there is an added element of risk. The testing phase is the first event for which timing, storage, input/output transfers are experienced as distinguished from analysed.
One of the greatest advantages of the waterfall approach is that development teams and customers agree precisely what will be delivered at an early stage. This removes the risk of scope creep and allows developers to accurately forecast the project completion date. In addition, a customer presence is only needed at the beginning of the project (when scoping the requirements). The waterfall methodology also allows for measurable progress. Because the entire project is scoped out, it's easier to determine where you are in the project's lifecycle. It removes the risk of a disjointed application as it adopts a wholistic approach to development.
Unfortunately it also means projects aren't as flexible. A comprehensive list of requirements are formulated at the beginning. Consequently it becomes much more difficult to alter or add features once the design stage has begun. There is minimal customer collaboration as the customer does not play an active role in development once the requirements backlog has been completed. The fact the customer only receives a final product limits the opportunity to receive user feedback during development. However if you know what your end user wants, waterfall is often an effective choice.
The project team spends a short period of time (a iteration) building a small part of the project to integrate into the application. This allows the team and business owner to build, measure and learn from iterations. The customer has an early opportunity to see completed work and is able to make changes throughout development. However, this opens the door for scope creep. Between the scoping phase and the completion of the development phase, customers will often want to include new features in the project. These features aren't planned or assigned to iterations and are not included in costing/time estimates.
Agile allows developers to prioritise certain features, hence an MVP (minimum viable product) can be produced quite quickly. The customer can then begin planning further iterations to improve on the MVP after user acceptance testing (UAT) is completed. The diagram below is an overview of the software development process for an agile project. The product backlog is completed and subsequently broken down into iteration backlog's. Each iteration is deployed to beta and development environments. Once the project's tests pass, it can be released to a production environment.
A waterfall project is more linear than the graphic above. Rather than including a feedback loop where you iterate to the next sprint, everything is completed based on the product backlog and deployed to the testing environments before it's deployed to the production environments.
Fixed Price Fixed Scope (Waterfall) Versus Flexible Scope or Flexible Time (Agile)
There are two commonly used methods for pricing a project. A development company can either offer a fixed price or a variable price dictated by time and materials. As mentioned above, the waterfall methodology lends itself to fixed pricing. The model is ideal for small and medium level projects with clear and well-defined requirements. With a fixed pricing strategy the customer knows exactly what the project will cost, allowing them to accurately allocate budget. This makes it appear low-risk option for the customer with well defined requirements. However, the risk around User Acceptance testing and unknown unknowns e.g technical debts, decisions and shifting perception means that the developer has to factor in this risk to the price on top of their estimations. The pros and cons of the fixed price model are outlined in the table below.
The time and materials pricing model is most beneficial for customers that want a flexible and agile project. The model allows software providers to adopt an agile methodology. At the beginning of the project, estimates are given based on how much the developer believes it may cost. However the final figure is calculated at the end of a project, and will reflect the time spent in development and any materials used. This is scary! However, there is a solution. If the time is fixed and everyone agrees upon the fixed time the scope can be varied back to ensure the most value is being delivered within the timer period. This means the scope can adjust per iteration. New items can be added or removed.
Requirements can change frequently without the development company attempting to forecast these changes at the beginning of a project. The risks are low for a software provider under this model as their time is compensated so they aren't motivated to multiply or inflate estimations. However, the customer has a greater degree of control. By keeping the requirements relatively similar to those scoped at the beginning of the project, the price won't fluctuate too much from any estimates given. Keep in mind that if new requirements need to be added, then this can be done at the customers request. WorkingMouse utilises the agile scrum development methodology. This enables for a backlog of requirements to be ordered by priority with time. This enables the customer to see and choose what is of value for the next iteration. The image below represents what a scrum backlog looks like. The items can be prioritised up and down. They also usually have time estimations if they where originally estimated. This enables the product owner and team to decide value in moving requirements from the backlog into the next iteration.
Each methodology has its own strengths and weaknesses. Early on, WorkingMouse essentially operated as an agile evangelist. We believed there was one right answer when it came to a development approach and it was agile. However we've grown since then. In doing so we've recognised that waterfall is a valid development approach with its own advantages. We've allowed our partners to decide which methodology they would like to use, presenting the advantages and disadvantages of each approach.
If you're struggling to decide, or have a question we'd love to lend our expertise. Contact us with your questions.
If the project timeline is fixed and can not be moved, Waterfall will offer a more predictable outcome. If you need to get the project delivered in a short amount of time, Agile is the appropriate choice here where action and getting things built is more important than documentation and process.How do you choose between Waterfall and Agile? ›
An Agile methodology is a superior choice when the client is uncertain about requirements or wants to be closely involved in the development process, and if timelines are short and they want rapid delivery. Waterfall is superior if there are complex dependencies, but Agile is preferable when dependencies are minimal.Can you tell me the difference between Waterfall and Agile in what kind of project should one be applied and not the other? ›
Agile and Waterfall are two popular methods for organizing projects. Waterfall is a more traditional approach to project management, involving a linear flow. Agile, on the other hand, embraces an iterative process. Waterfall is best for projects with concrete timelines and well-defined deliverables.Is Agile more successful than Waterfall? ›
There is plenty of supporting evidence that Agile wins out over Waterfall Projects. That data comes from 25 years of studying project success and failure rates is pretty clear. Agile projects are 2X more likely to succeed and less than half as likely to fail than Waterfall.Why people prefer Agile instead of Waterfall nowadays? ›
Agile projects are typically cheaper and can be delivered quickly. They offer greater flexibility, but also produce less predictable results due to the uncertainty and unclear nature of many of the project characteristics. Waterfall projects are typically more expensive and take longer to deliver.Why should I choose waterfall model? ›
The advantages of the waterfall methodology are that: Requirements are completed early in the project, enabling the team to define the entire project scope, create a complete schedule, and design the overall application.What is the main advantage of the Waterfall methodology over Agile approach? ›
They are commonly applied to software development, and thus, project management as well. The main difference between agile and waterfall is that waterfall projects are completed sequentially whereas agile projects are completed iteratively in a cycle.Why using Agile is a better choice for this project situation? ›
Agile methods can help teams manage work more efficiently and do the work more effectively while delivering the highest quality product within the constraints of the budget.Why we choose Agile methodology? ›
Well executed Agile software development methodology helps teams significantly improve the quality of their software at each release. Not only that, it allows teams to adapt to change quickly. The Agile process consists of short, time-boxed iterations known as sprints. Each sprint results in a working product.Can we work on Agile and Waterfall together in one project? ›
The Agile-Waterfall Hybrid is often considered a smart approach for adopting both methodologies without compromising too much, essentially utilizing the best of both worlds.
What do you think are the 1 to 3 most important differences between the waterfall methodology and the Agile methodology for application development? ›
Agile performs testing concurrently with software development, whereas in Waterfall methodology, testing comes after the “Build” phase. Agile allows changes in project development requirements, whereas Waterfall has no scope of changing the requirements once the project development starts.What are three ways that Waterfall development differs from Agile development? ›
|This method is flexible and allows changes for the progress of the project soon after the first stage of designing gets completed.||Once the project development begins, there is no way to change the specifications if any are required.|
Agile Projects Succeed More Frequently.
Agile teams also develop in short iterations and take items all the way to done within a sprint to further reduce risk.
It's clear that agile is more flexible, and waterfall is more rigid. Each methodology has its pros and cons, meaning these methodologies are better suited for different project types.What are two reasons agile development is more beneficial than Waterfall? ›
Improves collaboration among teams- 54% Enhances the quality level of software in organizations- 52% Results in enhanced customer satisfaction- 49% Speeds time to market- 43%Why is scrum more successful than Waterfall? ›
Scrum enables rapid reaction to changing customer requirements. Using the waterfall process, customers were required to state up-front, exactly what they wanted when asking for bespoke software development.Why is Agile better than Waterfall medium? ›
Agile can accommodate new, evolving requirements any time during the project, whereas it is not possible Waterfall to go back to a completed phase and make changes.What are 3 benefits to using the waterfall model? ›
Advantages of waterfall model
This model is simple and easy to understand and use. It is easy to manage due to the rigidity of the model – each phase has specific deliverables and a review process. In this model phases are processed and completed one at a time. Phases do not overlap.
It works well for smaller and low budget projects where requirements are very well understood. Clearly defined stages and well understood. It is easy to arrange tasks. Process and results are well documented.Is waterfall model best? ›
The Waterfall model is the right choice for projects that don't require simultaneous changes. Let's face it, some deliverables require revisions. And if you're going to use Waterfall, it's not worth it. Make sure that the requirements are set and stable so the end-product can be met accordingly, and on time.
Agile produces important metrics like lead time, cycle time, and throughput that helps measure the team's performance, identify bottlenecks and make data-driven decisions to correct them. The Agile framework is a powerful tool that helps managers, team members, and clients.What is the biggest similarity between Agile and Waterfall? ›
Similarities Between Agile and Waterfall
They perform the same activities, which include collecting requirements, designing, developing, testing, and deploying. The foundation of a project involves planning, bringing the project to life, and monitoring the project's progress in the two methodologies.
It was found that the nature of project, development team skills, project constraints, customer involvement and organizational culture are the key factors that should guide decision makers in the selection of an appropriate Agile method based on the value these factors have for different organizations and/or different ...When Agile methodologies are not the best choice? ›
When not to use Agile methodology? There are certain industries that don't do very well with the increased risk associated with Agile development: finance being one of them. This industry, by its very nature, relies on the predictability of its processes. Any deviation from the norm could lead to a costly mistake.What are the top two reasons for adopting Agile? ›
- Faster time to market.
- Early ROI.
- Feedback from real customers.
- Build the right products.
- Early risk reduction.
Agile was designed for software development teams as a time-focused, iterative way of achieving continuous value delivery. Developers were looking for a way to add flexibility, transparency, and communication to their processes.Which methodology is best for Agile? ›
Scrum. Scrum is, undoubtedly, the most used of the many frameworks underpinning Agile methodology. Scrum is characterised by cycles or stages of development, known as sprints, and by the maximisation of development time for a software product towards a goal, the Product Goal.Can you use user stories in Waterfall? ›
User stories are one technique that can provide context for great conversations regardless of methodology. They can align waterfall and agile practices a bit more and still leave timing and level of detail up to the approach.Can you do Agile with a small team? ›
Agile makes sense for small teams because it allows them to manage their work in a more efficient and effective way. By using an agile approach, team members can always be working on the most important tasks and they can rapidly respond to changes in requirements.Why would you want to blend the Agile and Waterfall approaches? ›
The most important benefits of a hybrid management approach come as a result of the cross-pollination between the strengths of waterfall and agile methodologies, and include: Improving predictability. Improving the ability to respond in a timely manner to feedback from users, team members, and management.
If you simply want to produce work faster, try Scrum. If you want to improve your production process, use Kanban. If your projects demand a linear workflow, implement Waterfall.What are some of the advantages of Scrum over the Waterfall method? ›
The advantage of Scrum over waterfall is that this agile structure provides some “wiggle room,” so changes can be made to features, functionality or even scope throughout the course of the project.What is the main problem with the waterfall model? ›
Waterfall Model - Disadvantages
The disadvantage of waterfall development is that it does not allow much reflection or revision. Once an application is in the testing stage, it is very difficult to go back and change something that was not well-documented or thought upon in the concept stage.
Waterfall is a better method when a project must meet strict regulations as it requires deliverables for each phase before proceeding to the next one. Alternatively, Agile is better suited for teams that plan on moving fast, experimenting with direction and don't know how the final project will look before they start.What are two critical areas that differentiate Agile from Waterfall? ›
Agile and waterfall are two distinctive methodologies of processes to complete projects or work items. Agile is an iterative methodology that incorporates a cyclic and collaborative process. Waterfall is a sequential methodology that can also be collaborative, but tasks are generally handled in a more linear process.Is agile more successful than Waterfall? ›
There is plenty of supporting evidence that Agile wins out over Waterfall Projects. That data comes from 25 years of studying project success and failure rates is pretty clear. Agile projects are 2X more likely to succeed and less than half as likely to fail than Waterfall.What is the most important agile value? ›
According to the Agile Manifesto, the more important values are individuals and interactions, working software, customer collaboration, and responding to change. Agile organizations use processes and tools, appropriate documentation, contracts, and plans to support the more important values.Why is the agile method faster? ›
The real reason why agile is able to deliver the product faster to market is that it implicitly applies the 80/20 rule, where product owner prioritizes the features to be implemented first, based on their values (ROI) to the end product.What is the main advantage of the waterfall methodology over Agile approach? ›
They are commonly applied to software development, and thus, project management as well. The main difference between agile and waterfall is that waterfall projects are completed sequentially whereas agile projects are completed iteratively in a cycle.Why Waterfall model is best? ›
The advantages of the waterfall methodology are that: Requirements are completed early in the project, enabling the team to define the entire project scope, create a complete schedule, and design the overall application.
With Agile software development, teams can quickly adapt to requirements changes without negatively impacting release dates. Not only that, Agile helps reduce technical debt, improve customer satisfaction and deliver a higher quality product.Which model is better than waterfall model? ›
The Agile methodology promotes the continuous interaction of the development and testing during the SDLC process of any project. Unlike the waterfall model, the development and testing activities in the agile model are simultaneous.
Better Quality: Because it is iterative, one big benefit of agile methodology is the ability to find problems and create solutions quickly and efficiently. The flexibility of the agile method allows project teams to respond to customer reaction and constantly improve the product.Why Agile is the best process model? ›
Agile teams are known to be highly efficient at getting work done. Because Agile teams share a collaborative culture, efficiencies tend to have a ripple effect. Look for an Agile solutions provides insights into delivery trends to remove bottlenecks and adapt workflow processes for improved productivity.In which situation agile model is preferred? ›
This is the best methodology to follow in case of complex projects. A complex project may have various interconnected phases and each stage may be dependent on many others rather than a single one as in simple projects. So, Agile methods are preferred for large and complex projects.What factors need to be considered when choosing an Agile approach? ›
- ADAPTIVE TO CUSTOMER NEEDS. Agile is more flexible, adapting to changes much more rapidly than other software development methods. ...
- STYLE OF WORK. ...
- GREATER CUSTOMER SATISFACTION. ...
- FASTER DEPLOYMENT TIMES. ...
- CONTINUOUS FEEDBACK. ...
- MINIMAL DISRUPTIONS.
- Waterfall Model. ...
- Agile Software Development. ...
- Lean Model. ...
- Iterative and Incremental Method. ...
- Prototyping. ...
- Spiral Method. ...
- DevOps Model.
If we must pinpoint the main difference between Scrum and Waterfall as methodologies for software development, it would be that Scrum is value-based with shorter iterations and Waterfall is schedule-based with clearly estimated costs and plan.What are two reasons agile development is more beneficial than waterfall? ›
Improves collaboration among teams- 54% Enhances the quality level of software in organizations- 52% Results in enhanced customer satisfaction- 49% Speeds time to market- 43%