An organization's dynamic evolution necessitates the use of a structured framework to accommodate its various processes and guidelines. Let's take a closer look at a perfect example of a framework for efficient management of IT enhancements – software development life cycle (SDLC) models.
Table of contents:
- Software development life cycle (SDLC) – meaning and definition
- What are the main phases of the software development life cycle?
- What are the main SDLC models?
- SDLC in software engineering – summary
Software development life cycle (SDLC) – meaning and definition
While the company's primary focus should always be on delivery, the need to improve internal processes cannot be overstated. To put it another way, learning how to do things should be just as important as actually doing them. Incorporating software development life cycle (SDLC) models into business structures is based on the very same logic.
The SDLC refers to – and describes – the iterative process of developing new software through the use of specific guidelines, proven methodologies, and industry-specific standards. Precisely speaking, this structured approach outlines the stages that the development team must go through to create software that meets the customer's expectations; starting from pre-production research and planning to post-production upkeep. All while delivering high-quality results.
Furthermore, when used correctly, SDLC can help your company stand out from the crowd by eliminating inefficiencies common in your industry and lowering overall costs. This is due to the fact that a methodical approach makes it easier to identify areas for improvement and track the impact of changes on overall productivity and software quality. Most importantly, all of this occurs in the shortest time possible.
What are the main phases of the Software Development Life Cycle?
The SDLC is organized around a series of phases that are involved in software development. Depending on the SDLC framework, workflows may include multiple transitions or iterations across phases before reaching the final phase. But what are they exactly?
Phase 1: Planning and requirements gathering
The SDLC process starts with collecting and analyzing requirements provided by customers, stakeholders, and industry experts, which are then validated through market research. While collecting insights, project managers and developers must collaborate with business, operations, leadership segments, and security teams to ensure that all aspects of the project are taken into account. Based on these inputs, a strategy is developed.
This stage may last for a long time and includes provisions for strategic changes as the SDLC progresses. As data is gathered and project goals are established, they are transformed into defined system functions for the organization's growth. All results are then collected in Software Requirement Specification (SRS).
Phase 2: Feasibility study
Following the software specification, a feasibility study must be performed to determine the software's viability. All of the components required for the finished software must be listed and discussed thoroughly by executive decision-makers. At this stage, it is recommended to focus on the five feasibility factors:
- economic (budget constraints),
- legal (dependence on the law),
- technical (skills and technology stack),
- scheduling (timeframe).
All discoveries should be embedded into the previously mentioned Software Requirement Specification (SRS) document, which contains a list of approved product requirements to be designed and developed. Remember that systems analysis is critical in determining a company's needs, how they can be met, who will be in charge of each aspect of the project, and what kind of timeline can be anticipated.
Phase 3: Design
Once all requirements are discussed, the software design process can begin. Proven design patterns and frameworks for application architecture can be used to build an application from pre-existing components, thereby promoting reuse and standardization.
This is the stage at which end users discuss and decide on their specific business information requirements for the proposed system, including:
- Architecture – by specifying which programming language should be used, listing relevant industry practices, and referring to any templates used.
- Security – by determining what security measures the software will employ to safeguard the data it handles.
- Platforms – by identifying a software's platform or operating system.
- Interface – by determining how users will interact with/navigate within the software and how the software will respond when used.
- Programming – by listing the problem-solving methods that the software will use as well as how it will perform different types of tasks; also by specifying how the software will communicate with other pieces of software or devices.
All design approaches for the product – based on the requirements specified in the SRS – should be collected in the Design Document Specification (DDS). The DDS is then reviewed by all stakeholders, and the best design approach is chosen based on various parameters (i.e., design modularity, risk assessment, product robustness, and budget and time constraints).
Prototypes, pseudocode, minimal viable products (MVPs), and/or architecture reports and diagrams with the necessary technology details are examples of the desired output. Nonetheless, some SDLC processes avoid prototyping because it can waste time on a design that might never be implemented.
Phase 4: Product development / Coding
This is the stage at which the software is actually created. Programmers begin the coding process, which is the most time-consuming phase of SDLC. At this point, agile methodologies – such as sprints and iterations – could be introduced to reduce the time required to code efficiently. As a result, IT infrastructure, database design, and code itself are created.
Depending on the chosen approach, high-quality software is produced by adhering the code to the design document's original guidelines or by combining them with feedback insights from various teams and business stakeholders. Either way, the goal is to ensure that everyone's expectations are met. The output of this phase is working software, which must be tested before final deployment.
Phase 5: Testing and integration
After all of the code for the software has been written and assembled, the next stage of development is to run tests to ensure that it is functional. This phase generates quantifiable data about the software's level of uncertainty. However, such insight is only useful if it allows for the acquisition of valuable information about the risks and consequences of sound decision-making.
At this phase, the code is constantly reviewed and corrected. Testing should be repeated until the product is stable, free of bugs, and meets the quality standard. The new software should be also simple to integrate with libraries, databases, or other programs used by your company.
The techniques used for testing differ depending on the active phase of development. Automated testing is standard, but it must be detailed because mediocre tests are no longer acceptable these days, so retesting and regression testing are performed until the software is ready to meet all customer expectations.
Phase 6: Deployment
After the code has been tested and confirmed to work flawlessly, the software is being introduced to its first users in the production environment, which is referred to as the UAT (User Acceptance Testing).
Before a software product can be shipped, several procedures and preparation activities must be completed, including documentation, transfer of ownership and licensing, and installation on customer systems. User manuals or instructional videos may need to be created and released alongside the software to ensure that users understand how to use it.
After any technical deployment issues are resolved, the software is released to end-users if there are no bugs or defects.
Phase 7: Updating and maintenance
Many people overlook or underestimate the importance of the final stage of the software development life cycle. However, according to the company's policies, the software quickly becomes eligible for periodic software updates.
Real issues usually arise once the software is installed and the client begins using it, so any requirements must be met regularly. The maintenance stage typically lasts until a piece of software reaches the end of its useful life or is replaced by a new version. Bug fixes, updates, documentation, and new features can be added as needed to keep the software running smoothly for users.
This stage is also critical for keeping the SDLC moving, as the opportunities to create new updates or other pieces of software will be easily identified by maintaining and testing your software.
What are the main SDLC models?
Before beginning software development, the development team must determine an appropriate life cycle model. Depending on the product specifications and industry, different SDLC models are used by various organizations and developers. Each model has stages that are the same or similar to those listed above, but the development approach might seem a little different.
Among the most popular SDLC models we can distinguish:
- The Waterfall Model – This is the most-known SDLC model, with its cascading stages one below the other. Each stage is represented by an autonomous, highly skilled IT professional (or group of professionals) who is solely accountable for their respective “components” of the software system. The end of one stage signals the start of the next, and each step included detailed process documentation. Still, as you can’t go back, if one person fails to deliver their “part” – the project might surely fail as well.
- V-Model – The V-model, also known as the verification or validation model, operates with the testing and development stages in parallel. This means that tests are being run simultaneously as initial pieces of software are being tested. Therefore, the coding stage links the two processes at the bottom of the “V”. In effect, the project is moving more quickly and more closely to the client's vision.
- Iterative Model – Each development cycle in this process results in an incomplete but deployable version of the software. The first iteration implements only a subset of the software requirements (i.e., the ones with the highest priority or the highest risk of failure), and each subsequent version adds more. The final iteration includes the entire requirement set.
- The Spiral Model – This is a risk-based process model. The development team assesses the project and decides which other process models to include. Phases are completed iteratively until the final product is created.
- Incremental Model – This model is similar to the waterfall model. It contains waterfall processes divided into sections (which consist of iterations). The software requirements are separated at the start of the project, and the waterfall SDLC model is followed for each of these so that the final piece of software receives updates and new features regularly.
Which SDLC model is suitable for my project?
“Every business is a software business”
– Watts S. Humphrey, the father of quality in software and CMMI
The purpose of an SDLC application is to define the activities and steps involved in developing specific software (i.e., customized software) as well as the relationship between the SDLC and other organizational methodologies. Following that, the concept is applied to the planning, design, construction, and delivery processes. Bear in mind that when choosing the right model for your company you should always take your business environment (and needs) into account.
The Waterfall model, for example, is considered to work well for managing high-risk activities when the users' needs and requirements are clearly stated. However, due to a lack of feedback and flexibility, users cannot return to a phase once completed. As a result, if a problem arises in any preceding steps, there is no way to correct it (fast). On the other hand, the iterative approach allows for changes at any stage of development – including them in the next iteration – so that needs can be met on time.
When it comes to changes, it's worth noting that Incremental models are also advantageous when customers can't precisely define their needs. The V-model, on the other hand, is ideal for constant, unchangeable requirements.
And, if you need a high-risk project (one with a high level of uncertainty and variability in requirements), take a closer look at the Spiral model, which is "encapsulating" the version of the chosen model based on an ongoing risk analysis. This combination reduces risk while meeting all user requirements through proper planning. Nonetheless, the risk of failure is most significant in the absence of adequate risk assessment.
SDLC in software engineering – summary
As you may have discovered today, choosing the right software development model can help you avoid project failure, delay, or overbudgeting. Introducing SDLC methodology tailored to your project's needs is an excellent way to ensure that you don't overlook anything critical when designing a new piece of software and deliver within the time frame specified. Not only will your development process be more efficient, but it will also enable more precise identification of potential issues or areas for further improvement, as well as provide a framework to plan around when beginning a new project.
Nonetheless, applying the life cycle approach to any project takes time. Even if some steps appear to be more difficult than others, all must be completed. Also, whether discussing the Iterative or Waterfall models, keep in mind that neither project will be successful unless the customer is involved in each development phase.
Keep in mind that software development life cycle models are more of a how-to guide than a recipe for success. In fact, the SDLC pipeline and framework can be as diverse as the number of organizations that use them. Therefore, each company should use the best strategy for their specific needs. If you need a helping hand in selecting the best approach for your project, don't hesitate to reach out to Codete.