For many C-level managers, initiating a custom software development project can be quite a challenge. A large number of technical details and uncertainties may seem a barrier to getting positive results in the end. Yet, the good news is that this barrier is possible to overcome. You just need to know how a system development life cycle (SDLC) should go and what to expect from each of its phases.
This article will describe the basics of the SDLC process and explain how everything works in practice. We’ll also outline the main advantages that you’ll get if you follow one of the SDLC methodologies.
What is a system development life cycle?
The system development life cycle is a process of creating software products that consists of multiple steps. It is also sometimes referred to as the “application development life-cycle”. In most cases, it starts from the company’s decision to build an information system and ends with continuous maintenance that lasts until the system is removed from exploitation.
Nowadays, the SDLC approach associates more with innovative solutions based on state-of-the-art technologies. However, the term “system development life cycle” was coined more than half a century ago. Back in the 1960s, IT teams started using it to define the process of building information systems in a structured way. Of course, the system development life cycle methods have changed since that time. But the main idea and core theoretical background remain the same.
In particular, a system development life cycle process aims to deliver high-quality software solutions that meet all the client’s requirements and are built on time and on budget. Following a set of predefined sequential phases ensures that the work will be efficient, and the results will be predictable.
By the way, the phrase “system development life cycle” can sometimes have a broader meaning, covering both a hardware and a software part of IT infrastructure. But for the purposes of this article, we’ll use it as a synonym of the term “software development life cycle”.
Software development life cycle: process
As mentioned, the process of a system development life cycle includes several SDLC phases. The exact number of phases varies from five to seven, depending on the specifics of a project and a particular methodology that a team applies. We’ll describe the seven-stage version of a system development life cycle since it will allow you to see the bigger picture.
Ideation is the first phase of a system development life cycle. Its purpose is to define the product idea and determine what user problem the future solution should solve. Oftentimes, development teams aren’t involved in this SDLC stage since the client starts looking for programmers when the product vision already exists. The estimation of required resources and a timeframe can also be considered at this point, but only at a very high level.
That’s when a client and development team dive into details. The task is to gather, discuss, and describe user requirements for the future information system and ensure that programmers have enough data to build the right product. After the system analysis is complete, all parties involved in the product creation process should have a clear vision of how the solution must look and work. Besides the scope of the project, a client and development team set a deadline and calculate costs needed to bring the idea to reality.
The design stage of a system development life cycle is all about visualization. A system architect describes how all product components will interact with each other, defines security levels, and outlines the way the data will be transmitted. At the same time, UI and UX designers translate a product idea into schemes, layouts, and wireframes. In general, the system design phase is the first important milestone in a software development process since it marks a transition from theory to tangible deliverables.
At the development phase, software engineers build an actual product. It usually requires a significant amount of time as compared to the previous three system development life cycle stages. As a rule, the coding team includes front-end programmers and back-end programmers who are responsible for different development areas. The ultimate result of this stage should be a working solution along with source code documentation.
During the quality assurance phase, testers have to make sure that a software solution is bug-free and meets all the requirements. There are many types of testing: usability testing, performance testing, security testing, and so on. Usually, a product undergoes several types of testing before the release. If a bug is detected, the product is passed on to programmers again so they can fix it.
At the deployment stage of a software development life cycle, a finished product is rolled out in a production environment. It is either released to be downloaded by end-users or installed on the client’s premises and prepared to start running there.
Building custom software is nothing like purchasing a table for your office. To get lasting benefits from a digital product, you have to keep it relevant. It’s just impossible to develop an information system once and use it for many years without support and updates. The maintenance stage covers everything that happens after the system is launched. For example, it can include repairs in case of system failures, adding new features, and upgrades.
Besides, system development life cycle stages don’t always go one after another in a linear manner. Building software systems is a rather complex endeavor. So, in some instances, various stages of the system development life cycle can be repeated.
Examples of the SDLC in action
The SDLC is a foundational concept that can be implemented in practice in numerous different ways. Teams decide which system development life cycle methodology to follow based on the project’s specifics, programmers’ experience, client’s preferences, and other factors. But no matter which option they choose, the process will contain all SDLC phases. The difference is how these phases are structured and which one gets the largest share of the attention.
System development life cycle: waterfall model
The waterfall is considered the most traditional and rigid system development life cycle type. It provides a defined framework for a development process, and a team can hardly deviate from it. The SDLC stages in the waterfall go one after another in a sequential manner. It means that a development team can proceed to the next stage only after the previous one is complete.
Other key characteristics of a waterfall approach usually include the fixed price and strict deadlines. Since this SDLC model doesn’t imply the possibility to iterate, it’s difficult to implement changes after the project kick-off. Due to this, the waterfall methodology fits well short-term projects which have clear user requirements.
System development life cycle: agile model
The agile methodology represents the modern approach to project management. It allows teams to develop software products incrementally, using short cycles called “sprints”. Each sprint contains at least five out of seven stages of a system development life cycle: requirements, system design, development, QA, and deployment. After a sprint is completed, a client gets one piece of the product functionality (“increment”) that can potentially be released and used by end-users.
Since the product is created feature by feature, programmers can easily make changes to a system if necessary. A high flexibility level makes a development process adaptable to dynamic market conditions, ensuring that a client will get a relevant product in the end. Also, active customer involvement minimizes the risk of investing in a software solution that doesn’t satisfy user needs.
System development life cycle: other models
Waterfall and agile are the most popular software development life cycle models. But there are many more SDLC frameworks that you can choose for your project, for example:
- Spiral model. It combines a traditional approach and iterative process, emphasizing the importance of risk analysis.
- V-model. It’s also referred to as a validation and verification approach. In V-model, testing is performed after each development phase.
- Big Band model. It’s the least structured of all SDLC methodologies. The Big Bang model requires minimum planning, and a development process is based on the resources available at a specific moment.
- RAD model. The abbreviation stands for “rapid application development”. It focuses on fast prototyping, rapid delivery, and gathering user feedback.
To better meet the client’s requirements, a development team can also use a hybrid approach and combine several models in one project.
How to choose the SDLC model?
Ideally, a development team and a client should select a software development life cycle model together. Here are the main criteria you must take into account:
- Needs and concerns of stakeholders (e.g., business owners, employees, end-users)
- Project’s specifics (e.g., scope, requirements, budget, timeframe, technologies)
- A team’s size and skill set (i.e., if they have worked with a particular model or not)
For instance, if creating solid documentation is important for a client, it’s better to choose a waterfall or V-shape model. In case a priority is fast getting to the market, then a RAD or agile methodology will be a more suitable option.
Benefits of a well-defined system development life cycle
Why is having a system development life cycle important for project success? As mentioned, it helps teams deliver top-notch digital products that meet all the clients’ needs. But not only that. Other benefits of a well-defined SDLC include:
- better management control over the entire project
- transparency and visibility of all the processes
- clarity of requirements
- a single vision of a product for all the parties involved
- predictable results in terms of time, costs, and deliverables
- reduced risk of going off the track
Besides, if a team follows a system development life cycle, it’s mentally more oriented on results. It means that there will be less wasted effort, so a client can expect better ROI.
Custom software development is a complex process in a majority of cases. If you don’t follow the predefined life cycle phases, it’ll be rather difficult to harness the chaos and avoid the most dangerous mistakes. Nowadays, there are a variety of SDLC models to choose from. But no matter which methodology the team will use, it will help you get a high-quality software solution, save costs, and reduce time to market.
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