What Is a Software Process Model? 8 Models You Should Know

Software processes refer to the coherent set of activities, tasks and methods used to develop any sort of software product. The process typically involves requirements gathering and documenting, designing, implementation, testing, deployment, maintenance and other necessary phases to ensure that the resulting software meets the desired quality and functionality requirement.

The process of developing software is usually met with several challenges. Hence having a structured approach and breaking the whole process down into stages in prior becomes a necessity. And here’s where the role of the software process model comes in.

A software process model- definition

A software process model is a specific representation or framework that details the development process from a particular perspective. The goal of a software process model is to provide clear direction for controlling and coordinating the tasks to reach the end results efficiently as the software development process is a bit overwhelming and involves a lot more than technical knowledge.

Developers use a software process model as a tool to map every step of their projects. It allows development teams to follow the predefined set of tasks and methods that cover all the necessary steps in the software development process. They can catch errors or defects early in the development cycle while getting a clear picture of the project status.

8 types of software process models you should know

There are several types of software process models that meet different requirements. Here is some example of popular software process model you should know when outlining your development process.

1. Waterfall model

The waterfall model is one of the traditional process models that represent the software development process as a linear and sequential flow. This model displays each step of the development process as a separate step and eliminate all sort of overlapping in the phases. Requirements, design, implementation, testing, operation and maintenance are the phases one takes. So, for example, the testing phase in the development process begins only if the previous implementation phase is reviewed thoroughly.

Some of the major advantages are as follows,

• It is simple and easy to use.
• It is easy to manage with each phase having specific deliveries and review process.
• Phases can be completed one at a time.
• Process and results are well documented.
• Clearly defined stages.
• It works best in cases where the requirements are understood completely.

2. V model

The V model is referred to as the Verification and Validation model and is considered an extension of the waterfall model. Instead of moving down in a linear way like the waterfall model, the V model is run by curving upwards after the coding stage. It illustrates the importance of testing at each stage of the software development life cycle. Whenever a stage is completed, a test is performed to assess its functionality and validate requirements. Even if the V model is very rigid and offers very limited flexibility,

• It saves a lot of time as testing activities happen well before coding.
• The framework is straightforward.
• Detects can be found in the earlier stage.
• Provides a proactive error-tracking feature.
• The design of the model is quite simple.

3. Spiral model

This risk-driven software process model is similar to the waterfall model but includes risk assessment. This process model looks like a coil with many loops and each loop of the spiral is the phase in the software development process. However, the number of loops may vary from project to project depending on the requirements. It is well suited for projects with a great deal of uncertainty about requirements.

• The software can be produced early in the software life cycle.
• Additional functionality can be added at later phases.
• It works best for large, complex or high-risk projects.
• Continuous development help in risk management.

4. Incremental model

The incremental model is a software development approach where each module passes through the phases of requirements, design, implementation and testing phases until the complete system is achieved. So, here the requirements are divided into multiple builds and each build has its own life cycle. This model has certain advantages,

• This model is more flexible to changing scope and requirements.
• Breaking down tasks is effortless by using the divide-and-conquer method.
• Generating functional software quickly and early in the software life cycle leads to faster development.
• Easier to manage risk.
• Easier to manage each iteration.
• Functionalities are achieved, analysed and checked thoroughly.

5. Iterative model

The iterative model is pretty similar to the incremental model. This model involves breaking the development process into smaller, iterative cycles or stages, with each iteration focusing on a specific set of requirements or features. The development does not begin with a full specification of requirements, rather it begins by specifying and implementing just part of the software. So, the product can be constantly improved with the addition of new features during each iteration.

• This model is best suited for agile organisations.
• This process is more flexible.
• The products can be built and improved step by step.
• Errors or bugs in the system can be identified early and resolved during iteration.
• It is easier to get the reliable user feedback.

6. RAD model

The Rapid Action Development (RAD) model is based on prototyping without any specific planning. The RAD approach considers the chances that clients may not have a precise idea of their needs until they witness the software’s functionality, so too much emphasis on planning is not necessary. That is why more attention is provided to the development task.

• It ensures faster end delivery of the software as it is highly iterative.
• RAD offers more client involvement.
• It utilises a repository of components for reuse and that leads to fewer errors.
• It requires less development and maintenance cost.
• Any sort of risks can be addressed immediately.

7. Prototyping model

The prototyping model is used when the customer is not sure about the exact project requirements beforehand. So, a prototype (an early draft) of the end system or product is created early in the development process for the customer, in order to get feedback and refine the requirement. So, it is basically a close replica of the final software. And once the final acceptable prototype is achieved, it continues to full development. 

Some of the key advantages include,

• It is flexible in design.
• If needed, new requirements can be easily accommodated.
• It saves time and cost.
• A greater level of customer satisfaction can be achieved.
• It is ideal for online system.

8. Agile model

The agile model is an umbrella term that is based on a set of values and principles outlined in the Agile Manifesto, which emphasise individuals and interactions, working software, customer collaboration, and responsiveness to change. The core purpose of adopting an agile methodology is to equip the development team to be responsive to change in an unpredictable environment.

• It provides the opportunity for clients to be involved throughout the project.
• It offers transparency, feedback integration and quality-control features.
• It works in small prints focusing on continuous delivery.
• The cost is predictable and limited.

Factors to keep in mind when choosing a software process model

So, there is numerous software process model you can choose from when starting your next project. But which one is right for you?

If you are aware of your requirements well, it turns easier to select a model that best matches your needs.

• Go through the project requirements to choose a model that fits the project’s needs.
• The complexity of the project should be taken into account to determine whether it requires constant monitoring and requirement from the clients.
• Consider who your end users are.
• Check the resources available for the project, including the team's size, expertise, and budget, should also be considered.
• Assessing the project size is a must
• The skills and knowledge of the team should be considered as some process models might require certain skills.
• The specific needs and preferences of the client should also be taken into account.
• And lastly but most importantly, get the best developer on board.

However, there is no simple answer to the question of which methodology is best for software development. Yet since having a process model is crucial to lay down the framework for any business consider the above-mentioned tips and tricks to select the appropriate process model.