Comparison of different Life Cycle Models

The Classical Waterfall Model

The Classical Waterfall Model is the foundation upon which all other life cycle models are built. It's a fantastic model. The Classical Waterfall model, on the other hand, cannot be employed in real-world project development because it lacks a method for correcting faults that occur during one of the stages but are discovered afterward. The introduction of feedback pathways in the Iterative Waterfall model solves this issue.

Advantages of the Classical Waterfall Model

The waterfall model is an idealized software development approach. Because it is so basic, it may serve as a foundation for different software development life cycle models. Some of the primary benefits of this SDLC methodology are listed below −

  • This model is straightforward and easy to comprehend.

  • In this paradigm, phases are handled one by one.

  • The model's stages are all properly described.

  • The milestones in this paradigm are highly obvious and widely known.

  • The process, activities, and outcomes are all meticulously recorded

  • Good habits are reinforced: define before designing and designing before coding.

  • This paradigm works effectively for smaller projects and those with well-defined needs.

Drawbacks of the Classical Waterfall Model

We can't utilize the traditional waterfall model in actual projects because of its flaws; instead, we use different software development lifecycle models that are based on the original waterfall model. The following are some of the model's key flaws −

  • No feedback path: In a traditional waterfall model, software evolves from one phase to the next in a cascade-like fashion. It is assumed that no errors are made by developers at any time throughout the development process. As a result, it lacks any kind of error-correcting system.

  • Vary requests are difficult to accommodate: This approach implies that all client needs can be thoroughly and accurately specified at the start of the project, but in reality, customers' requirements change over time. After the requirements definition step is completed, it is difficult to accommodate any modification requests.

  • No phase overlap: According to this paradigm, a new phase can only begin after the preceding phase has been completed. This, however, cannot be maintained in real-world enterprises. Phases may overlap to improve efficiency and save costs.

Iterative Waterfall Model

The Iterative Waterfall Paradigm is perhaps the most widely used software development model. This model is easy to use and comprehend. However, this approach is only appropriate for well-understood issues; it is not appropriate for the creation of extremely big projects or projects with a huge number of hazards.

Advantages of the Iterative Waterfall Model

  • There are no feedback pathways in the traditional waterfall approach, hence there is no mechanism for mistake correction. However, in the iterative waterfall approach, the feedback channel from one phase to the previous phase allows for the correction of mistakes, and these changes are mirrored in subsequent stages

  • Simple to understand and use — The iterative waterfall paradigm is extremely simple to comprehend and apply. As a result, it's one of the most used software development models.

  • Cost-Effective - Changing the strategy or needs in the model is very cost-effective. Furthermore, it is ideally suited for dynamic businesses.

  • Well-organized - In this approach, documentation takes up less time, allowing the team to focus on development and design.

Drawbacks of the Iterative Waterfall Model

  • Change requests are difficult to integrate - The main disadvantage of the iterative waterfall approach is that all needs must be defined explicitly before the development phase can begin. Customers may modify their requirements over time, but the iterative waterfall methodology does not allow for modification requests submitted after the development phase has begun.

  • The use of incremental delivery is not recommended - The whole program is produced and tested before being delivered to the client under the iterative waterfall process. There isn't any room for a middle delivery. As a result, clients must wait a long time to get the software.

  • Phase overlap is not permitted - The iterative waterfall model presupposes that one phase may begin following the completion of the preceding phase. However, in actual projects, phases may overlap to save time and effort.

  • Risk management is not encouraged - Various forms of dangers may afflict projects. However, the Iterative Waterfall Model lacks a risk management mechanism.

Prototyping Approach

The prototyping model is appropriate for projects when the client needs or technological solutions are unclear. Before the project begins, these risks must be recognized. This paradigm is particularly popular for the construction of the project's user interface.

Advantages of Prototyping Approach

Using a prototype model has a number of benefits, including −

  • Customers get an early say in the product, which boosts customer satisfaction.

  • Errors and missing functionality are quickly recognized.

  • Prototypes may be utilized in more complex projects in the future

  • It stresses teamwork and adaptable design techniques.

  • The product's functionality is better understood by users.

  • Customer feedback that comes in faster gives you a better sense of what they want.

Drawbacks of Prototyping Model

When compared to other development approaches, such as the spiral or Waterfall model, the fundamental downside of this methodology is that it is more time and money consuming. Some businesses may not see the advantage in pursuing this method since prototypes are often abandoned.

Evolutionary Model

The evolutionary paradigm is appropriate for big projects that may be broken down into a series of modules for gradual development and delivery. Object-oriented development projects often use this paradigm. This paradigm is only utilized if the consumer accepts the system's incremental delivery.


  • In an evolutionary model, a user is given the opportunity to test a partly constructed system.

  • It decreases errors since the main modules are well tested.


  • It might be difficult to separate an issue into many versions that are acceptable to the client and can be executed and supplied in stages.

Spiral Model

Because it contains all other life cycle models, the spiral model is called a meta-model. This model's major qualities are flexibility and risk management. The spiral model is well suited to the creation of technically demanding and massive software that is vulnerable to a variety of hazards that are difficult to predict at the outset of the project. However, this model is more complicated than the others.

Spiral Model Benefits

  • Risk Management

  • Large projects will benefit from this.

  • Requirement Freedom

  • Customer satisfaction is the key.

Spiral Model Drawbacks

  • The spiral model has many major drawbacks, which are listed below.

  • Complicated

  • Pricey

  • There is much too much reliance on Risk Analysis.

  • Time management is challenging.

Agile Model

The Agile paradigm was created with the goal of swiftly incorporating change requests. Requirements are split into little components that may be created progressively under this methodology. However, the Agile model's core premise is to provide an increment to the client after each Timebox. An iteration's end date is set and cannot be changed. This agility is attained by eliminating time and effort-consuming tasks.

Agile Method Benefits

  • Continual Delivery

  • Communication with customers on a one-on-one basis.

  • Design that is both efficient and meets the needs of the company.

  • Changes may be made at any moment.

  • It cuts down on overall development time.

Agile Model Drawbacks

  • Due to a lack of formal records, there is a misunderstanding, and important choices made at various stages might be misconstrued by different team members at any moment.

  • Maintenance of the completed project might become challenging due to a lack of sufficient documentation after the project is completed and the developers are assigned to another project.

Choosing the Right Life Cycle Model for a Project

The most crucial duty is to choose the right lifecycle model to execute a project. It may be chosen by considering the benefits and drawbacks of different models. The following are the several problems that are examined before adopting a good life cycle model −

  • Software characteristics should be developed − The life cycle model used is primarily determined by the sort of software being produced. The agile paradigm is preferred for small service projects. The Iterative Waterfall paradigm, on the other hand, may be preferable for product and embedded development. An object-oriented project may be developed using the evolutionary approach. The project's user interface is mostly created using a prototyping technique.

  • Development team characteristics −The skill level of team members is a key aspect in determining which life cycle model to utilize. Even embedded software may be produced utilizing the Iterative Waterfall technique if the development team has prior expertise with comparable software. Even a basic data processing application may need a prototype methodology if the development team is completely inexperienced.

  • Project risk − If the risks are limited and can be predicted at the outset of the project, a prototyping approach might be effective. The spiral model is the appropriate model to utilize if the risks are difficult to predict at the start of the project but are anticipated to rise as the development progresses.

  • Client characteristics −If the customer is unfamiliar with computers, the requirements are likely to change often since developing full, consistent, and clear needs would be challenging. As a result, a prototyping model may be required to reduce customer change requests in the future. The customer's trust in the development team is initially great. Because no operational software is evident throughout the long development phase, client trust tends to wane. As a result, the evolutionary paradigm is beneficial since customers may experience partly functioning software far sooner than they can experience fully functional software. Another benefit of the evolutionary approach is that it alleviates the customer's anxiety about learning a new system.