Difference Between Scrum vs Waterfall Model: Whether to go with Scrum vs Waterfall Model is a much-debated topic in the industry. As we all know these are two of the popular software development processes used by organizations all over the world. Both have their own pros and cons. Scrum is widely used these days but the waterfall model also has its place in the market and use by many software houses.
When it comes to deciding which one is better, there are many factors that should be considered like the company culture, team size, and management.
When it comes to selecting a software development methodology, one will certainly be confused with the wide array of options available in the market. There are at least ten popular methodologies like Agile, RUP (Rational Unified Process) and so on available in the market.
But the two most widely used methodologies are Scrum methodology and Waterfall Methodology. As both of them are popular; it becomes difficult for the companies to select one of them. Let us have a look at Scrum Methodology Vs Waterfall Model.
Waterfall Model
Waterfall Model is an older type of software development process which is also known as sequential waterfall. This model describes the order for each step in the life cycle of system development. It is a sequential process where development activities are carried out in a rigid order.
It is called a waterfall as the water or project progresses from activity to activity. In this model, once the development process starts, no one is allowed to move back or forth. All the project phases have fixed time and deliverables.
This is the traditional model which has been used in software development for the past several years. In this methodology, there is a strict phase for requirement analysis, testing, design, and so on. Waterfall provides a rigid structure to the software development process and has a strict definition of roles for each phase of development. The only problem is that it is not very flexible as small changes in the requirement will require rework or more time to be spent in development.
Scrum Methodology:
Scrum methodology, also known as agile is a popular software development process widely used these days. This methodology has gained much popularity after several projects following this process showed good results. It was developed by Ken Schwaber and Jeff Sutherland in the year 1995.
This methodology has been designed to help the software development process in an environment of uncertainty. It ensures to bring the organization closer to value by delivering quickly and adapting more frequently with desired outcomes. As per the scrum methodology, a cross-functional development team works together to get the best possible software in planning time.
Scrum is a holistic model of the software development process where there is no restriction for any phase of a project. In this methodology, there is no rigid structure and one can take any activity at any time depending upon the requirement. The product owner is the one who decides which task will be performed by whom and when.
There are also three roles that are played in Scrum methodology. These are product owner, scrum master, and development team.
Scrum is a much flexible process. It is very easy to modify and can overcome risks easily. The drawbacks of the Scrum methodology are those roles should be assigned before starting a project, a team cannot be added or subtracted in the middle of the project.
Comparison between Scrum vs Waterfall Model
There are several categories that can be compared between Scrum vs Waterfall Model. The table below shows the comparison of the Scrum vs Waterfall Model in terms of cost, team size, methodology, phase, and more.
Scrum SDLC:
- Scrum is a lightweight process which does not require much time for training and overhead expenses. As per the Scrum methodology team size ranges from 5-9 members.
- Development team works in a continuous cycle where they are expected to deliver working product incrementally on frequent basis with desired quality and functionality.
- Product owner is the one who is responsible for scope, schedule and budget. In Scrum methodology team works very closely with product owner and the team is an integral part of the development process.
- Unlike Waterfall method, Scrum methodology does not have different roles for different phases and anyone can take care of the task. Anyone who is interested in doing a particular task or wants to learn new skill can do it easily.
- Scrum methodology is very flexible. It can be customized to suit the requirement and team size of the project.
- As per this methodology, requirements are gathered and validated in a pre-planning meeting.
- Scrum methodology does not have any overhead costs as no documents are written, there are no change orders, project managers are not required and there is no separate testing team.
- The results of a Scrum project can be measured in terms of quality and functionality.
Waterfall SDLC
- Waterfall methodology is a traditional approach where every phase of the project is carried out by specialized person. This process has high overhead cost and takes more time due to communication gap between different roles.
- In Waterfall methodology, firstly requirements are gathered by a business analyst and then design is done by a separate team. There is a need of experienced project managers, testers and configuration specialists for a proper execution of the project. On large scale projects, there are multiple feature teams which draw much overhead expenses.
- Waterfall methodology has a rigid structure, phases and large team size. These all factors lead to more overhead expenses.
- Waterfall methodology has a fixed time frame as the project can be completed only after completion of all phases in given time period.
- Budget in waterfall is very clear and open whereas there are hidden costs in Scrum method if the number of iterations and sprints is large.
- As the development team has to work for long duration, there are chances that they become demotivated and lose interest as they have to deliver the project in longer duration with no clear idea of user requirements.
- Waterfall methodology lacks flexibility and can be modified or changed during the project execution.
- Regarding quality, waterfall methodology is better as there is a chance that product owner may add new requirements or change existing ones which is not possible in Scrum as it delivers fixed functionality which is already planned.
Scrum vs Waterfall Model Table:
| Scrum | Waterfall Model |
|---|---|
| Scrum has only two roles Product Owner and Team Member who perform similar tasks with flexibility to cross over between them. The project scope is planned by the team whereas in Waterfall methodology it is done by project managers and business analysts. | In waterfall, there are too many separate stages in which each performs a unique task. |
| In scrum, users can change the requirements during the project development which is not possible in the Waterfall methodology. | Since user requirements are not known beforehand, it is very difficult to decide upon the project budget. Scrum methodology has a fixed number of sprints in which it delivers the functionalities required by the product owner. These features can be used for estimating the project cost accurately. |
| It is less costly than Waterfall methodology, as in waterfall there are components like Business Analysts, Project Managers, Configuration Analysts, and Testers who have high overhead costs. | It has the advantage of a clear time frame as the project can be delivered only after all phases are completed within a given time period. |
| Scrum methodology has more flexibility as the scope of the project can be changed according to the requirement changes which is not possible in Waterfall methodology. | It is a very clear and open method while there are hidden costs in Scrum if the number of iterations and sprints are large. |
| In the waterfall method, there is a longer lead time in comparison to Scrum as the development team has to work for a long period of time. | It is very effective in the case of large projects with strict requirements but it lacks flexibility and can be modified or changed during project execution. |
| It is not effective for small projects as it requires the participation of the product owner, team members, and end-users during each iteration. | Water Fall Methodology is more efficient when the project is very large and there are various departments involved such as operations, programming, testing, etc. as they can work independently without interfering with each other’s functions. |
| Scrum is best suited for projects where there are complex integration dependencies and the development team can deal with them in short intervals. | Waterfall always has well-defined phases which act as a time box where each phase will take a specific time period to complete. This methodology has fixed deliverables each phase and it also reduces the changes made in project scope by the product owner. |
Because of the large number of methodologies, the confusion in choosing the best methodology grows. Scrum is the best for agile projects. The waterfall is better when it comes to developing massive software applications and has more advantages than disadvantages.
Conclusion:
In conclusion, both Scrum vs Waterfall Model methodologies have their own advantages and disadvantages. There is no comparison between these two methods because it depends upon the project type, team size, and product owner’s requirement which methodology should be adopted. I hope the difference between the Scrum vs Waterfall Models will help you get an idea of both.
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