Phases of the Software Development Life Cycle

Diana Ipacs

April 22, 2024

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The Software Development Life Cycle consists of several phases. Let's see what they are and what challenges they bring to the process!

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What is the Software Development Life Cycle (SDLC)?

Developing first-rate software tends to be a complex affair. The software development life cycle is a structured process adopted by IT industries for developing high-quality, efficient software products.

The SDLC defines several stages including requirements gathering, planning, system design, implementation, testing, deployment, and maintenance. All of these are vital in ensuring the software meets (or, in an ideal world, exceeds) customer expectations and is delivered within time and cost constraints.

Let’s see what these phases entail, the tasks that need to be done in each, and their most important challenges and/or pitfalls! As with anything that involves a complex process, a team and a client, quite a few of these exist, so it’s worth keeping them in mind throughout the development process.

Before we go on, please note that this is a general description of the software development life cycle. The exact phases of the software development life cycle can vary based on a variety of factors, such as:

  1. 1
    Development methodology
  2. 2
    Project size and complexity
  3. 3
    Nature of the project
  4. 4
    Team composition and expertise.

For example, different methodologies shape the software development life cycle differently. The Waterfall methodology has a sequential approach, with clear boundaries between each phase. In contrast, the Agile methodology employs an iterative approach, frequently revisiting phases like requirements and design based on ongoing feedback and evolving understanding.

Teams can adapt the software life cycle structure to align with the specific requirements and challenges of their projects, which enhances their chance of success.


Software development life cycle

Requirements Gathering and Analysis

This is arguably the most crucial phase in the software development life cycle process. It involves communication with the customer to understand what they want from the software. Requirements are gathered from the customer and analyzed for their validity and the possibility of incorporating them into the system to be developed. This phase is all about the "what"—what are we building and for whom?

  1. 1
    Identifying stakeholders: Determine all parties involved in the project, including end-users, project sponsors, subject matter experts, etc.
  2. 2
    Gathering requirements: Collect all necessary information about what the system needs to accomplish from the stakeholders.
  3. 3
    Analyzing requirements: Assess the gathered requirements for feasibility, clarity, and potential contradictions.
  4. 4
    Validating requirements: Verify that the requirements meet the needs of the stakeholders and the objectives of the project.
  5. 5
    Documenting requirements: Record all requirements in a formal document, providing a clear, agreed-upon roadmap for the project.

Bluebird Insights: Quoted from our Experts

As a business analyst, this might be the step where you have the most influence on a project’s success. This is when it is necessary to assess business needs, coordinate with various stakeholders, and contribute to their synthesis. Here, in-depth knowledge is particularly important: if any requirement is poorly defined or overlooked at this stage, it can distort the planning and implementation phase and require redesigning. Worse still, problems may only become apparent during testing, at which point they can only be remedied through change requests. Both scenarios can lead to high costs and time losses.

A good example might be if, in the case of a core banking project replacement, an integration with an important but not very visible ancillary system is not properly assessed. Another example could be if our IT solutions do not comply with data protection laws to the extent required by law.

Richard Patyi | LinkedIn

Business Analyst

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Potential challenges

Miscommunication or misunderstanding about requirements is a common pitfall in this phase of the software development life cycle. Pay special attention to clear and thorough communication with stakeholders, and make sure that requirements are well-documented and agreed upon. Avoid (overly) technical jargon and double-check if you fully understand the customer's needs and expectations.

Approximate duration

The duration of each phase in the software development life cycle can vary greatly depending on the nature of the project, its complexity, the methodology used (e.g., Waterfall, Agile), the team's expertise, and various other factors.

However, it might be useful to indicate their approximate length, so here it is: Requirements gathering and analysis can consume about 10-15% of the total project time. This includes understanding the business needs, gathering and documenting requirements, and confirming and finalizing the requirements with stakeholders.

Bluebird Insights: Quoted from our Experts

In the case of banking and financial software development, you need to pay special attention to security issues. This is why it is important to involve legal areas like risk management and compliance in the planning in some form. This is especially true for systems that work with client data, financial transaction-related data, encryption, and authentication. Compared to the average project lifecycle, banks need to react relatively quickly to legislative changes, because non-compliance can lead to serious fines and sanctions.

For example, the introduction of GDPR legislation in the EU posed a significant challenge a few years ago for the sector—as a larger bank might have several hundred or thousand different systems that could be interconnected in various ways. In such cases, coordinating parallel developments is important because some level of harmonization is necessary when data is transferred between systems.

Richard Patyi | LinkedIn

Business Analyst

Richard Patyi profile
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Planning

The planning phase, which follows the requirements gathering and analysis, sets the strategic direction for the entire project. This phase translates the "what" from the requirements phase into the "how." Essentially, it outlines how the gathered requirements will be turned into a functional software system. Here, the focus shifts to planning resources, time, and strategies to meet the outlined requirements.

  1. 1
    Defining Scope: Clearly outline what will be included in the software project, setting boundaries and limits.
  2. 2
    Resource Allocation: Determine the necessary human, technological, and financial resources needed for each phase of the project.
  3. 3
    Risk Assessment: Identify potential challenges and devise strategies to mitigate or overcome them.
  4. 4
    Establishing Timelines: Set milestones, deliverables, and deadlines based on the project's objectives.
  5. 5
    Setting Communication Strategies: Establish a clear communication plan detailing how information will be relayed among team members and stakeholders.

Potential Challenges

A common challenge in the planning phase is setting unrealistic timelines or underestimating resource needs, which can lead to project delays and budget overruns. Another pitfall is the failure to foresee potential risks or not having a clear contingency plan. Just as miscommunication can distort requirements, inadequate planning can lead to a project that’s unfeasible or misaligned with stakeholder needs. Make sure that your planning is thorough, adaptable, and is in sync with the requirements you previously established.

Bluebird Insights: Quoted from our Experts

Human resource allocation is one of the most critical points of project planning. It may happen that not everyone is delegated full-time to a given project but instead has their time divided among other tasks. This limits the possibilities for meetings and cooperation at the planning level. In such cases, it is advisable to specifically lay down on which days or periods it is essential for the person to focus on the project.

A similar risk may be the involvement of partner areas: if they are involved in addition to their basic tasks, project work may not necessarily be a priority for them (for example, because they need to deal with customers). In such cases, it's wise to anticipate this early on and specifically request fly-in people from key areas because delays can easily occur due to these circumstances.

Richard Patyi | LinkedIn

Business Analyst

Richard Patyi profile
Bluebird logo emblem

Approximate Duration

The duration of the planning phase, like other stages, varies based on numerous factors, such as the project’s scope and complexity. Generally, planning might occupy around 10-15% of the total project time. It's crucial to note that while the requirements phase sets the direction, the planning phase ensures the project is set on a feasible and strategic path, and they often go hand-in-hand. Any changes or clarifications in requirements can lead back to adjustments in planning.


Design

In the design phase of the software development life cycle, the team defines the software's architecture, components, and interface while ensuring the system will meet all specified requirements. This phase is crucial for laying down the foundational design specifications that will guide the subsequent development efforts. Some possible steps include:

  1. 1
    Defining system architecture: Develop a comprehensive architecture of the software system that integrates hardware, software, and network resources. This architecture should address both functional and non-functional requirements (leading to scalability, performance, and security).
  2. 2
    Designing user interface: Design the user interfaces with a focus on usability and aesthetics. This includes crafting a consistent and intuitive navigation scheme and ensuring that the interfaces are accessible to all intended users, considering various user capabilities.
  3. 3
    Designing database structure: Establish the schema for databases by determining tables, columns, relationships, and data types. This design should optimize for efficiency and integrity of data operations, and include considerations for future scalability.
  4. 4
    Creating data flow diagrams: Construct data flow diagrams to map out the flow of information within the system. These diagrams help visualize the paths that data takes through the system, which is critical for identifying potential bottlenecks.
  5. 5
    Documenting design specifications: Consolidate all design elements into a comprehensive document. This document should include detailed descriptions of the system architecture, user interface, database structure, and data flows.

Potential challenges

A common trap in this phase of the software development life cycle is rushing into development without a solid design or failing to consider scalability and security issues. IT architects and designers should design a system that meets the requirements and is both scalable and secure. They should also focus on creating a design that is easy to understand and implement by the developers.

Approximate duration

The design phase may take around 15-20% of the total project time. This includes defining the software architecture, creating detailed design documents, selecting the technology stack, and finalizing the tools and platforms.


Implementation or Coding

On receiving the system design documents, the work is divided into modules/units and actual coding starts. This is the phase where developers start to build the entire system by writing code using the chosen programming language, following the requirements documented in the previous stage.

  1. 1
    Writing code: Convert the design specifications into executable code using the chosen programming languages.
  2. 2
    Reviewing code: Conduct peer reviews to identify and correct any coding errors or inefficiencies.
  3. 3
    Unit testing: Following the test pyramid, test individual parts of the software to verify that each performs as expected.
  4. 4
    Integration of modules: Combine various parts of the software to work together as a cohesive system.
  5. 5
    Documenting code and changes: Maintain clear records of code, any modifications, and the reasons behind them.

Potential challenges

Common pitfalls in the implementation phase in the software development life cycle include not following coding standards, not commenting code, and not performing unit testing. Developers should follow good coding practices, write clean and efficient code, use comments to explain complex parts of the code, and perform unit testing to catch errors early.

Approximate duration

This is usually the most time-consuming phase, potentially taking up to 30-40% of the total project time. It includes writing code, reviewing it, performing unit testing, and integrating different pieces of code.

Software development life cycle implementation phase

Testing

After the coding phase of the software development life cycle, the path is clear for the testing phase. In this stage, the developed software is tested thoroughly and any defects found are assigned to developers to get them fixed. Testing is done to ensure that the system behaves as expected and the requirements are successfully implemented.

  1. 1
    Creating test cases: Develop scenarios to test all parts of the software. They should cover all requirements and functionalities.
  2. 2
    Executing test cases: Run the test cases on the software, documenting any issues that arise.
  3. 3
    Identifying bugs and defects: Detect any software errors or areas where the software fails to meet requirements.
  4. 4
    Documenting test results: Record the results of each test case, noting any failures and their associated bugs.
  5. 5
    Retesting after bug fixes: After issues have been addressed, retest to confirm the fixes are successful.

Potential challenges

This phase can often be rushed, or not given enough emphasis. Ignoring some types of testing (like performance or security testing) can also be a trap. Testers should carefully choose the types of testing methods that are most suitable for the given project. They should also use automated testing tools where possible to increase efficiency. Testers must understand the software requirements well to be able to create effective test cases.

Approximate duration

Testing generally consumes around 20-25% of the total project time. This includes all types of testing: unit testing, integration testing, system testing, acceptance testing, and sometimes even non-functional testing like performance testing.

Interested in the testing life cycle, too? We have just the resource for you: our guide to the software testing life cycle.


Deployment

Once the software passes through all the phases of the software development life cycle without any issues, it goes through a deployment phase and is made available to the users. Sometimes, the software is rolled out in phases to a limited segment of users, and based on the feedback, the entire software is rolled out to all the users.

  1. 1
    Preparing deployment environment: Set up the live environment where the software will be installed.
  2. 2
    Deploying software: Move the software into the live environment, making it available to end users.
  3. 3
    Conducting smoke testing: Perform basic tests to ensure the deployed software runs as expected in the new environment.
  4. 4
    Conducting user training (if needed): Teach end-users how to use the software effectively.
  5. 5
    Transitioning to users: Hand over the software to the users for everyday use.

Potential challenges

The main pitfalls in deployment include not having a rollback plan, failing to consider the real-world environment, and not providing enough support post-deployment. DevOps engineers or system administrators, if involved, should ensure a smooth deployment process with minimal downtime. They should also have a contingency plan in case anything goes wrong during deployment.

Approximate duration

This phase can take about 5-10% of the total time. It includes tasks such as preparing the environment, deploying the software, and performing smoke testing to ensure everything is working fine.


Maintenance

After the deployment, maintenance starts. Maintenance involves implementing enhancements, doing bug fixes, and ensuring that the system continues to function without any issues, which requires periodic checking of the system.

  1. 1
    Monitoring system performance: Regularly check the software's performance to ensure it continues to meet user needs.
  2. 2
    Resolving issues: Address any problems that arise during the use of the software.
  3. 3
    Implementing enhancements: Add any new features or improvements based on user feedback or evolving needs.
  4. 4
    Conducting routine system checks: Conduct regular inspections of the system to preemptively catch any potential issues.
  5. 5
    Documenting changes and impacts: Keep a record of any changes made during maintenance and their impacts on the system.

Potential challenges

During the maintenance phase of the software development life cycle, challenges include not properly prioritizing issues and not allocating enough resources for ongoing maintenance. Support and maintenance teams should keep track of any reported issues and fix them based on their severity and impact. Regular checks should also be carried out to catch any potential issues before they become significant problems.

Approximate duration

This phase lasts as long as the software is in use and can potentially span years. It includes tasks such as resolving issues, adding new features, and improving the system.


Each of these stages is crucial for successful software development. These stages can be followed in a linear way in a Waterfall model, or they can be iteratively followed in an Agile model. Each model has its own strengths and weaknesses and is chosen based on the specific requirements of the project.


We hope you enjoyed our article on the software development life cycle. If your company is looking for IT professionals, including QA engineers and you are interested in IT recruitment or IT staff augmentation, please contact us and we will be happy to help you find the right person for the job.

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