Top 10 Software Development Models in a Nutshell

Successful projects are thoroughly managed, it's a fact. Once you decide to develop a product, whether it's a simple MVP or a complex system, the question will arise: how to properly organize the development process? 

Every software has its journey in which it goes through several development steps - from an idea and design to release and support. This process is named the software development life cycle (SDLC), where a variety of software development models is available to choose from, and each organizes the process in its own way.

So, should you rigidly plan all development phases? Or is it much better to work in short iterations? Our article will tell you about the most widely used methodologies and share how to choose the one that's best for you. Let's go!

Simply, software development models are various processes or methodologies that outline product life cycle stages, how to perform tasks, evaluate performance, and monitor development progress.

Each software development model:

Throughout development, a product goes through a series of steps in each model. Usually, these steps include preparation, design, engineering, and follow-up maintenance. They can be named differently and/or subdivided into smaller pieces depending on the model. All you have to do is to pick the one that will best suit your needs and we are here to assist you with this.

It is no secret that the chosen approach determines either a tremendous success or a total failure of the project.

According to the PMI Global Project Management Survey, software development projects, in particular, are notorious for failing to deliver. 31% fail to meet their goals, about 43% are over budget, and 49% go beyond the agreed deadlines. As a result, only 15% of projects are on track. But don't stress out prematurely. We're here to tell you how the top 10 development models work to let you know which one you should pick to successfully complete your project as planned.

To choose among such a large variety of available models, you should know about all the subtleties that greatly influence the choice. Thus, you may ask what to pay attention to. Let us present to you the criteria which influence the choice:

Okay, we've discussed what influences the choice of a model. But who determines which development model will be used on a project? Mainly, a sales or pre-sales manager does it at the pre-sale stage. Alternatively, a project manager chooses it at the initial project stage.

There are more than 50 development models, and each of them is unique in its own way. Now we're going to talk about the ten most common and widely used.

The waterfall is the earliest approach for software development and has been used for several decades. About 56% of projects used waterfall in the last 12 months according to the PMI.

The main concept is that all development phases depend on each other. One stage should be fully completed before the next one begins to eliminate any overlaps. Thus a forward progression is formed, illustrated in a linear sequential flow.

Of course, this approach provides high predictability regarding the schedule and consumed resources but makes it impossible to account for new requirements that may appear during development. If you want to release an MVP with a minimal set of features for hypothesis testing, sadly, there's no way you'll be able to do that with waterfall. You cannot implement and test a new feature until the whole product is done.

The V model (Validation and Verification model) is a more "advanced" version of the waterfall version and well knоwn аs the vеrification and vаlidation mоdel. Key difference with the waterfall model is that here testing takes place at each step from the beginning of a project, rather than at the end of the whole process. This approach enables feedback from the earliest development stages and improves the overall product quality.

However, like the waterfall, V-model’s requirements gathering also happens at the outset and cannot be changed throughout software development, which means that the V-model is also not flexible. Although all bugs in requirements and architecture can be detected early on, changes will still be expensive and tricky to implement.

Unlike waterfall, iterative and incremental software development models do not need to plan the entire project management process. Instead, the goal is to apply repetitive development cycles to move a product forward with each iteration. During the development process programmers can figure out what works and what fails and adjust subsequent iterations with gained insights. 

In iterative and incremental models, each iteration can run in parallel to each other or sequentially, and software changes can be implemented at any time. Note, however, that changes cannot be radical. The initial requirements provide a framework that can be adjusted but still ensures a rigid structure for development.

The spiral model combines an iterative process and a sequential linear development model with a very high emphasis on risk analysis, which allows incremental product releases or incremental refinement through each iteration in the spiral.

In essence, the spiral model is a variant of the iterative one. Each spiral loop corresponds to one stage (iteration) of the software creation process and is broken down into four parts: planning, risk analysis, development & testing, and evaluation.

The rapid application development model (RAD) uses minimal planning in favor of rapid prototyping, ensuring quick results in a short timeframe. A team develops components in parallel, releases core features, and subsequent cycles allow adding modifications. The process fully ends only when software is fully implemented. Since there is no detailed pre-planning, the model makes it fairly easy to incorporate changes into the development process. 

Rational Unified Process (RUP) is a software design and development model focused on using the Unified Modeling Language (UML). 

RUP follows an iterative development process. At the end of each iteration, which on average lasts from 2 to 4 weeks, a team must achieve the goals planned for that iteration, create or refine features and produce an intermediate, yet functional, version of the final product. The lеvеl of customer involvement, dоcumentation depth аnd iteration length varies according to specific project gоаls.

Agile is not a model itself, but a bundle of concepts and ideas for agile development. The movement appeared in 2001 in the Agile Manifesto - the outcome of development methodologies generalization.

Each Agile iteration commonly takes about a few weeks and delivers a completely operating software version. As a result, Agile models focus more on the rapid delivery of a functioning app part and testing and are less burdened by rigorous software documentation.

Agile is about teamwork and close collaboration with clients. At the end of each iteration, they analyze the development progress and can reassess priorities for future milestones to ensure full alignment with end-user demands and business targets. Thus, Agile models tend to be characterized by regular releases and continuous software improvement through quick fixes, updates, and feature enhancements.

Sсrum is one of the commonly used agile methodologiеs. The workflow here is divided into sprints with 2-4 weeks duration. About 84% of respondents in the KPMG survey said their organization used either Sсrum or Kanban.

Before each new sprint, a team discusses the results of the previous one's, formulates tasks, identifies problems and possible solutions. After the goals are set, a new sprint starts. As a result, performed sprints are easy to compare with the previous ones, thereby managing the effectiveness of development. 

Scrum work empowers the team to analyze the process and see the opportunities for improvement they could use in the next sprint. 

Extreme Programming (XP) is another Agile model that favors frequent releases in short development cycles. The main difference with other Agile group models is that еxtreme рrogramming forces developers to create features only if they are truly needed. XP admits changes even after an iteration has begun.

XP's flexibility is somewhere in the middle between Scrum and Kanban: not аs structured as the former, but not as loose as the latter. Adjustments can be mаdе after each iteration, and еxtreme рrogramming teams usе test-driven development, paired progrаmming and continuous integration practices to guarantee product performanсе.

Kanban is based on visualizing a team's task completion process, and the aim is to reduce the number of unfinished tasks. The key distinguishing feature is that there are no pronounced iterations - the team performs individually created tasks. Furthermore, the tasks go through all stages on the board independently of the others. This ensures project progress transparency, showing the organization of tasks, and helps evaluate and point out the most urgent ones.

Summing up, the choice of an appropriate software development model depends on a set of factors and nuances that all together may seem like a nightmare to account for at once. 

Whether you are facing the dilemma of choosing the most efficient software development model, want to know more about them or just have an idea and want to implement it, contact us and we will be happy to assist you!