Eight Standard Software Development Models Explained in Depth

Perfect planning and execution are essential, especially in modern-day business where competition is intense. The leading software development companies need to understand the importance of selecting the best development model for the project and further enlighten themselves with the emerging and futuristic trends in software engineering before beginning the software development process to keep up with the exorbitant market.

For building good software, the software developers must complete the entire process thoroughly without missing a step. To accomplish this, Systems Development Life Cycle (SDLC) comes in handy as it gives the developer a profound structure to face the challenges during the software development process.

Software Development Life Cycle (SDLC) is a series of different phases that helps in understanding the overall software development process.  However, it is critical to know that the SDLC models have different methodologies for different software developments. Therefore, the makers should first narrow down to the most suitable software development model based on the requirement of their project.

In this article, we have done in-depth research on eight different software development models. In addition to this, we have also discussed the factors having a significant impact on the software development model selection process.

List of software development models

There are multiple software processes available businesses can use to meet different requirements. Here is an in-depth analysis of the top eight software development models.

Waterfall model

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The waterfall model is a well-thought, objective-driven, and sequential software development model. It is a prerequisite in this model to schedule and plan all the related activities before beginning the development. Every activity in the waterfall software process model is arranged linearly and is represented by different phases.

When to use it:

You must go for the waterfall model when the project does not have any ambiguous requirements. It means that the specified requirements should remain during the entire development cycle without any change. Moreover, the waterfall model works better when the technology used in the software development is clear and the risk in the project is minimal.

Pros of the model

• The waterfall model is easy to manage, understand and use
• Test scenarios are detailed and more transparent
• It is comparatively easier to arrange tasks in the Waterfall software process model

Cons of the model

• It is not easy to accommodate changes in the waterfall model
• If you have a complex, lengthier, or a bigger project, this model is not preferred
• It becomes challenging to monitor the progress within stages in the waterfall model

Incremental model

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As the name suggests, the entire system’s functionality is divided into small phases in the incremental model. After the division, all those small phases are delivered one after the other quickly. Thus, when new modules are added into the iterations, little to no changes are preferred in the modules earlier added.

The development process in the incremental software development model can be either parallel or sequential. However, with many repeated cycles, the sequential method can become costly and lengthy. While on the other hand, the parallel method helps in adding to the speed of the delivery.

When to use it

The incremental model is most effective when most of the project requirements are defined while other details are likely to evolve with time. In addition, if you want the product to use new technology and get it early in the market, the incremental model can prove beneficial. Also, you should go for the model if there are some high-risk features and goals involved in the project.

Pros of the model

• The software process model is flexible and less expensive to change scope and requirements
• The model lowers the initial delivery cost, and it is easier to test
• The developers find it easier to debug and manage risks
• In this model, the customer can respond to each phase or milestone

Cons of the model

• A clear and complete definition of the entire system is required before breaking it down and built incrementally
• Costly as compared to the waterfall model
• Good design and planning are required

Validation and verification model (V Model)

The validation and verification model is just an extension of the waterfall model. There is a corresponding testing phase for every development stage in this model. Moreover, as the V-shaped model grew from the waterfall, each stage begins only after the previous one has ended.  However, one major difference between the V-shaped and waterfall model is that the former one has an early test planning process.

When to use it

The V-shaped software development process model is the best fit for small to medium-sized projects. Also, it works well when the project’s requirements are clearly defined since it extends the waterfall model.  Businesses should opt for the V-shaped model when they have ample technical resources, and their developers are technically sound.

Pros of the model

• The model has proactive defect tracking, which helps in finding the bugs at an early stage.
• It is straightforward to use
• The test designing and planning activities are carried out well before the coding process has begun.
• It has shown a higher success rate as compared to the waterfall model

Cons of the model

• It is a very rigid software development process model
• In case any changes happen, the test documents and other required documents are needed to be updated
• There are no early prototypes of the software produced

Rapid Action Development (RAD) Model

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The Rapid Action Development (RAD) model focuses on gathering requirements by reusing software components, informal communication, etc. The model is based on prototyping and iterative development with ample focused planning.

There are different phases involved in the RAD model:

• Data modeling
• Process modeling
• Business modeling
• App generation
• Testing

When to use it

RAD model is highly recommended for the software that is recommended by UI-driven requirements. Moreover, the RAD model should be used when it is necessary to develop a system with scope for modulation in 2-3 months.

Pros of the model

• Better reusability of components
• Fosters customer feedbacks
• Reduces overall software development time
• No integration issues

Cons of the model

• Highly depended on the modeling skills
• Needs a strong team as well as individual performances for realizing the business requirements
• The cost to generate ‘automated cost’ and modelingis very high
• RAD can build a system that can be modularized

Also Read: Coding methodology for successful agile software development. Here are some tips for success.

Iterative Model

The iterative software development model is all about evolution and growth. In this, the software changes made on each iteration grow and evolve. The main focus of the iterative model is repetition. Thus, the developers don’t need to know the entire requirement of the project before working on the iterative model. Instead, they can implement a set of software requirements, evaluate and test them and then point to the further requirements.

When to use it

If the project is bigger and more complex, using the iterative model can be your best bet. The developers need to make sure that the large complex project is broken down into modules for the optimum use of the iterative model.  Moreover, it can also be used in systems with separated components, such as the ERP system.

Pros of the model

• It is easier to find flaws at the early stages; hence, it saves time
• More time is spent on productive designing and less on documenting
• It is simpler to get reliable user feedback

Cons of the model

• The model is not flexible enough and has no overlaps in each phase
• Issues in design may occur
• Very costly system architecture

Spiral Model

The spiral SDLC model amalgamates the features of the waterfall model and the prototyping model. As a result, it is one of the most flexible SDLC methods as it allows building highly customized software products. The spiral model is very similar to the incremental model, but it emphasizes risk analysis.

Also Read: Custom Software vs Off-the-shelf Software: How to select a better one for your business?

The spiral model has four main phases:

Planning phase: Important requirements such as System Recruitment Specifications (SRS) and Business Requirement Specifications (BRS) are collected in the planning phase.

Risk Analysis: Here, the potential risks in the software project are identified. Moreover, if the developers find any issue during the risk analysis, alternative solutions to curtail the issues are suggested.

Engineering phase: In this phase, the software is developed, and the testing at one end is done.

Output evaluation: In this phase, the customer is allowed to rate the outcome of the project. After this, the project continues to the next spiral.

When to use it

When risk evaluation and cost are essential in the project, one must opt for the spiral software development model.  Also, if significant changes are expected and you are using a new product line, the spiral model is a good choice. The model is also highly advisable in medium to high-risk projects.

Pros of the model

• The model has substantialdocumentation control and approval
• The developers have the flexibility to add more functionalities even at the later stages
• The product is developed early in the software development life cycle

Cons of the model

• Very costly; not suited for smaller projects with low budget
• For competent risk analysis, the businesses would require specific business expertise
• Proper risk analysis is very important for the overall success of the software project

Big Bang Model

The big bang model is like the ‘mercury among solids’ in the software development models. However, unlike the other models, there is no specific process to follow in the model.

Like the cosmological theory, the process of the big bang model has no structure in the beginning. Later, it shows rapid growth and expansion and thus aids in faster software development.

When to use it

One should use the big bang model when you are working on experimental and temporary software. This model is best suited for academic work or learning projects. Also, businesses can opt for this model when the software release date is not specified.

Pros of the model

• The model requires less planning and fewer resources
• It is cost-effective and easy to implement
• The big bang model is best suited for smaller projects.

Cons of the model

• In some rare cases, the big bang software development model is precarious and provides less return on investment.
• It is not suitable for more extensive, complex projects.
• The durability of the software project built through this model is questionable.

Also Read: Top reasons why outsourcing software development fails.

The Rational Unified Process (RUP)

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This process is a proper culmination of iterative and linear frameworks. The software development model divides the entire software development process into four different parts:

• Beginning
• Expansion
• Build up
• Transition

In this process, all the required activities of the development process are done parallelly. It is the reason this software development model helps in building flexible software solutions.

When to use it

RUP is extensively used in large and high-risk projects. In addition, if you wish to have high-quality software and a faster development process, Rational Unified Process should be your go-to SDLC model.

Pros of the model

• It focuses on the need for on-point and accurate documentation
• It is easier to make changes according to the requirements
• Integration is easy, and it happens throughout the software development

Cons of the model

• Only experts can perform optimum on this model
• The development process is quitecomplex
• Reuse of components is not possible

Factors impacting the selection of software process model

Enterprises have shown their trust in investing in software despite the adverse effects of the coronavirus pandemic that has hit the market worldwide. But to select the best software process models, businesses need to pay attention to certain important factors. For your benefit, we have listed them below.

Project necessities

Before initiating choosing a software model, businesses must understand the needs and requirements of the project. Moreover, you must clarify to your team to set clear expectations. Understanding the project requirements plays an important role in the hassle-free selection of the software development process model.

Project complexity levels

If you are aiming to build high-end software, its complexity levels are bound to remain high. Moreover, there might be instances where you cannot figure out the explicit requirement in a complex project.

Thus, to avoid the delay, analyze the project’s complexity and understand its actual needs before selecting the software lifecycle models.

Project Size

Having larger projects means you require more resources and a bigger team. And to work with bigger teams, you would require elaborative and extensive business management plans.  Therefore, businesses must consider the overall size of the project while selecting the SDLC models.

Understanding of the technology

Along with understanding the project’s requirements, businesses should be aware of the capabilities of their software development teams.  There is no point in selecting a high-end SDLC model with which the developers are not comfortable working.

Thus, the businesses must understand the experience of the developers with the software tools, language, and project domains. Having a full-throttle understanding of developers’ technological expertise will help simplify the software development model selection process.

Customer involvement

As the dynamic nature of the present business environment, the requirements of the modern-day customers are also dynamic. Thus, it is advisable to concern about customers’ views during the development process. For this, you can develop an MVP and release it to get feedback from the customers. Based on their response, you can make changes to the SDLC model if needed.

Conclusion

SDLC models are capable of offering a unique process for software development. In addition, these software development models help developers deal with various challenges during the development process. The key for the businesses here is to hire the best software development service providers who can efficiently leverage the full benefits of the software life cycle models like experienced professionals.