Explaining the Phases of the Software Development Lifecycle
How do developers make sure the app complies with all the required specifications? How do they test their codes? What are the suitable time frames for the requirements analysis?
Knowing answers to these questions helps software developers ensure smooth performance when working on new projects. But how do they understand what to do and when?
That’s when SDLC comes into play.
In this article, Qubit Labs discusses the software development lifecycle process and gives examples of how SDLC is used in practice, pointing out popular methodologies.
What is the Software Development Lifecycle?
The SDLC is a process that includes several specific stages. It begins at the time of the decision to create software and ends when developers stop providing software support services.
The software development lifecycle is critical during the project development because it helps each team member, from manager to programmer, monitor progress. Thus, this methodology improves the quality of software and facilitates the development process.
The software development lifecycle policy makes it easier for the organization to manage and regulate software development and code. The policy creates a secure and reliable environment, making the processes more efficient and for saving costs.
What is the software development lifecycle usefulness?
The SDLC allows companies to:
- Visualize the development process
- Manage the project
- Predict and plan the delivery of certain products during the development process
- Manage the risks of being over budget or exceeding the deadlines
- Quickly identify the phase of the development at any given period
The SDLC software development lifecycle is usually monitored by the project manager, who ensures the achievement of developers’ goals.
How does SDLC Software Development Life Cycle Work?
The SDLC is effective because it lowers the software development expenses while improving the quality and decreasing the production time. It helps to eliminate the typical issues by following a defined plan and preventing excessive fixes. The implementation of various software development lifecycle tools helps to achieve the mentioned goals by removing and addressing the pitfalls that might occur during the process.
What are the Software Development Lifecycle Phases?
The full lifecycle software development usually includes six phases, describing how exactly the software project should be developed. Although different companies give different names to these phases, let’s use the most common ones and take a closer look at them:
“What do we want?”
Before embarking on the project development, you need to know what exactly you want to create. What features does the project need to have? What functions does it have to avoid?
Although some people believe that software development is just about writing code, it has many more processes. You need to understand the volume and project boundaries before commencing writing the code. That’s the phase when you need to understand what exactly you’re going to build and why.
The requirement analysis SDLC phase implies cooperating with all the stakeholders, including leaders, clients, and developers. All members must stay on the same page to ensure the development of relevant project specifications.
Then, the business analysts study the received information, elaborate it, and turn it into the software requirement specification (SRS).
Apart from SRS, this stage includes:
- Defining the software quality attributes (SQA)
- Risk analysis (RA)
- Creating the validation and verification plans (V&V Plans)
- Establishing the software acceptance criteria (AC)
“How do we get what we want?”
The mentioned SRS is a reference point for the developers because it helps them to come up with a suitable product architecture.
During this stage, the software architects create the project skeleton based on the requirements. They define the necessary technologies, processes, linkages between the project’s parts, database structures, and data flow, to name a few.
The design stage of the full lifecycle software development means deciding how exactly the functions should be implemented. Therefore, it’s critical to engage the stakeholders during this stage to make sure the designed plan fits their requirements.
Cooperation with other parties is essential during each stage, but it’s vital at the design phase. Each stakeholder has to share their opinion regarding design so you can commence putting the plan into action.
The design documentation specification (DDS) is the result of this stage. It describes what has to be done and how exactly it should be done from the technical point of view. The DDS includes two parts — high-level design (HLD) and low-level design (LLD).
“Let’s create what we want”
That’s when software development takes place. The programmers receive software requirement specifications and design documentation specifications, moving to the development itself.
Practically, all the coding is performed during this stage of the software lifecycle development process. It’s here when the developers use the console and text editor. If the previous steps were implemented accurately, this step would be the least difficult.
It’s critical to use software development lifecycle tools during this stage to ensure consistent and clear communication between the team of developers and managers.
“Did we get what we wanted?”
Testing affects each stage of the software development lifecycle. It helps to determine bugs and see if the project works smoothly enough. The testers implement quality control procedures based on SQA, SRS, and DDS and the final product.
If there are defects or bugs, the specialists create the bug reports for the further elimination of detected issues. The process takes place until the product fits the initial requirements and desired quality.
“Let’s start using what we created”
That’s the critical stage of the lifecycle of software development because the product is finally ready. The team has tested the code and made sure it complies with all the initial specifications.
The goal of this SDLCs phase is to move the software from the testing environment to the operating environment. Apart from this, the developers can also configure the operating environment and install, configure, and launch the product.
“Let’s make our product closer to what we originally wanted”
Although the planning and requirement analysis stage of the lifecycle of software development is crucial, the project will need specific changes eventually. For example, the users might ask to add another function or update the libraries to make sure the product utilizes the newest tools.
After launching the product, the developers are often responsible for supporting it. They use various tools to monitor the product’s performance and ensure that the code works correctly.
If the software engineers don’t support their products, the latter might become unstable, not complying with the initial project requirements anymore.
Top Software Lifecycle Development Models and Methodologies
After reviewing the software development lifecycle phases, it’s time to address the methodologies. These are the methods that facilitate software development, which include rules, techniques, and principles that make the development processes more effective.
The interaction between the mentioned phases depends on the selected SDLC methodology. The most commonly used software development lifecycle models are the following:
This is the classical, one of the oldest software development lifecycle methodologies in which the development process looks like a flow, transferring from one stage to another, clearly in order. The stages are interdependent of each other, implying each stage should be completed before the next one begins.
The main advantage of this SDLC is that the quality can be assessed after each stage. However, it’s often criticized due to the absence of flexibility and the inability to take a step back and introduce changes, which makes testing more complicated.
- simple process scheme
- it doesn’t require high costs for communication
- easy to estimate the implementation expenditures
- substantial documentation spendings
- inability to predict all the nuances in advance, which often leads to delays in progress or lower quality
- impossible to introduce changes before finishing the product
Agile is a set of principles focused on making software development more flexible. Some of the most values of this SDLCs methodology include:
- people and their interactions are more important than processes and tools
- a product that works is more important than comprehensive documentation
- cooperation with the client is more important than harmonizing the agreement’s conditions
- the acceptance of the changes is more important than following the initial plan
Many frameworks and methods are related to this methodology, namely Scrum, Kanban, Lean, and XP.
This model implies dividing the development process into several sprints — the chunks of time within which the team has to achieve certain results.
- a smaller development team (compared to the Waterfall model)
- lower risks, lower project costs, and increased quality due to the early testing
- even load between the team members
- realistic estimation of the current state of the project
- the ability to make decisions and adapt faster
- the team has to be highly qualified to achieve the maximum results
- absence of the clear plan
This is an advanced version of the Waterfall software development lifecycle model. The developers monitor the process during each stage to make sure it’s time to move to the next phase. V-shaped models of the SDLC imply testing at the requirement analysis stage, and each phase has its own testing practices.
- strictly defined phases
- testing planning and system verification take place in the early stages
- improved time-management (compared to the Waterfall model)
- interim testing
- lack of flexibility
- insufficient risk analysis
This SDLC model focuses on analyzing the risk assessments and is perfect for cases when there’s no room for error. It looks like a spiral because it starts assessing the risks of the local programs, gradually moving to more complex tasks.
- increased focus on the risk assessment
- it’s possible to get stuck at an early stage
- the development process lasts for an extended period and is expensive
The principle that underlies the incremental SDLC model implies expanding the capabilities and completing the application’s modules and functions.
- no need to invest a lot of money in the initial phase
- it’s easy to receive feedback from the users and update the technical task
- the bugs cost less (it’s easier to eliminate them compared to Waterfall or V-shaped models)
- each development team comes up with its functionality and can develop the interface in its own way
- inability to precisely estimate the cost of the project
This software development lifecycle doesn’t imply following any specific process. There’s very little planning required, and the customer comes up with the requirements on the fly. It’s implemented for small projects with small teams.
- simple and doesn’t require management skills
- doesn’t require planning
- provides flexibility to the developers
- high risks and ambiguity
- doesn’t fit complex projects
Boost Your SDLC with Qubit Labs
The companies understand that the software product goes beyond programming. The software development lifecycle is gaining momentum because the businesses know that the idea is what kick-starts the project, while the maintenance is an integral part of the SDLC.
Also, strong communication within the team is a prerequisite for success, so the selected software development lifecycle methodology will significantly affect the results.
If you want to come up with a high-quality product that solves the business tasks, Qubit Labs will match you with vetted developers.
Feel free to reach out to us to discuss your ideas and turn them into industry-breaking solutions.