Understanding the software development life cycle [SDLC]
If your business needs software, you want to make sure it's done right. When choosing to partner with a software development company, you need to find one you can trust. Finally, when it comes to the process of software development itself, it is wise to understand the details of what is involved in top-tier software development. This is where the Software Development Life Cycle (SDLC) comes in.
SDLC is a process that involves a series of pre-planned actions that develop or alter software products. SDLC provides organizations with an efficient and systematic approach to developing software successfully. It is designed to create high-quality software most cost-effectively while consuming the smallest amount of production time possible. In this article, we will outline the phases of SDLC, the roles involved in the process, the benefits of SDLC and two of the most popular methodologies used today: waterfall and agile. After reading this you will have a better understanding of SDLC and this knowledge can help you to make a more informed decision when choosing a software house to build your software development project.
Benefits of SDLC
At its core, the software development life cycle provides a basis for streamlined project planning, estimating, and scheduling. It vastly improves the control and monitoring of large projects. It also creates a framework for a standard group of activities and deliverables, can be used for project progress tracking and control and helps improve client relations. SDLC forces software houses to increase the transparency of project planning to all stakeholders involved in the development process. Worth mentioning is the fact that SDLC decreases the total time spent on the project. All of the meticulous planning involved in SDLC for a software development project helps decrease project risk and project management overhead.
The phases of software development life cycle (SDLC)
1. Requirements collection and analysis
Requirements analysis is a fundamental stage of SDLC. Business requirements are collected in this phase. It is undertaken by project managers as well as stakeholders and involves input from the customer, sales team, market surveys as well as domain experts in the relevant industry. All this information is collected in order to plan the project roadmap. Besides, a product feasibility study for economic, operational, and technical fit is conducted. This study is used to define an assortment of technical approaches that could be undergone to complete the project successfully with as few risks as possible. In this phase, identification of the risks involved with the project is completed as well as an outlining of the quality assurance requirements.
General questions that might get answered during the requirements collection and analysis phase include:
- I/O considerations: what data interfaces should the software have?
- How much data will need to be stored and processed?
- How will users interact with the software?
- What features need to be included in the software?
- Who will use the system?
- What devices should be supported?
After the analysis is completed the information is used to define and document the product requirements for approval. This is facilitated by the creation of a Software Requirement Specification (SRS) document. This document contains an outline of all the product requirements that will be designed and developed for your software development project. The SRS also serves as a guide for the next phase (design). The business analyst and project manager would have the largest roles during this phase.
2. Software design and architecture
During this phase, the software architecture is created from the requirements specifications developed in the previous phase. It can be thought of as a blueprint that defines the system structure for the entire project. This design will be used in the next phase (implementation/coding).
The most important role in this phase is the software architect. This person attempts to describe the required operations and functions (such as business rules, screen, and database layouts) as well as create the architectural plan for the project. The design phase also involves a QA lead. This person comes up with a test strategy that includes what to test and how to test it. In this phase, a business analyst would provide requirements to the design team and review the solution design.
This is the phase of development, the longest phase of SDLC. System design documents are used to build the project. The development team is heavily involved in this phase. A development team can consist of a single developer or a group of developers with a team leader. A project manager or business analyst may also be involved. The project manager might monitor the project’s progress and the analyst might help by clarifying the requirements of the project.
4. Software testing
Once the code is developed the testing phase can begin. In this phase, the software created in the previous phase is tested against pre-set business requirements to ensure that the product is solving the needs identified during the first phase. This phase involves a multitude of functional testing types including acceptance testing, integration testing, and non-functional testing. The primary roles involved in this phase is obviously the QA team (and a QA lead if required). Sometimes business representatives are also involved as they check the software solution against their requirements.
5. Installation/Deployment of the software
In the installation/deployment phase the software solution is ready for the production environment and use by the end-user. This end user could be an internal group in a company or the general public. Or both. It all depends on the project. Implementation is meticulously planned.
The software product may be deployed in stages, released in a limited segment of the market to be tested in the real business environment. Developers may be involved to provide support in case critical bugs are discovered. At larger companies, it is common for a dedicated team to focus solely on releases. When the software is implemented the project manager communicates to the wider team what was accomplished and the results that followed.
6. Software maintenance
This phase of SDLC starts after the product has been released. Every problem that occurs after release, needs to be solved. Solving these problems is a process known as maintenance. Maintenance can involve repairs, software upgrades, and fixing the program if it shuts down unexpectedly. Besides, applications sometimes need to be upgraded or integrated with newer systems.
What is the waterfall model in SDLC?
The first process model to be introduced was the waterfall model. It is a linear approach to software development and also known as a linear-sequential model based on stages called milestones. One benefit of the waterfall model is that it is simple to both use and understand. In it each phase has to be finished before the next phase in the sequence can be started. There is never any overlap between phases.
The waterfall model is ideal when the business requirements are well established, and sufficient resources are available (both team-wise and capital-wise). It is an easy model to maintain as the phases are precise. Another plus is that results are well documented under the waterfall method. Also, the budget is pre-set and you know upfront the total cost of the project.
Not all projects are right for the waterfall model. Large and complex projects can carry high risk when used with this model if they implement new and innovative ideas that upfront is impossible to be rigidly defined. It also does not work with projects that have their requirements changed often as the waterfall model can’t adapt to changes in requirements.
What is the Agile model in SDLC?
The agile model is based on adaptive software development methods. This differs from more traditional SDLC models (such as the waterfall methodology) which are based on a predictive approach. In this model, the customer can see the result after every development iteration to see if she is satisfied with it or not. This allows the customer to introduce changes very early in the development cycle if the produced results do not meet expectations. The agile model is ideal when there’s a high risk of frequent changes to the business requirements. It requires only initial planning in order to start a project. However, with constant interactions, and no rigid development plan the project may go on for a long time and thus have unpredictable costs.
Understanding the Software Development Life Cycle can help you produce superior software and work better with the software house you choose for your project. In this article, we outlined the benefits of SDLC including increasing the development speed and helping to decrease project risk and project management overhead. We also went over the six phases of the software development life cycle including requirement collection and analysis, design, implementation/coding, testing, installation/deployment, and maintenance. Finally, we gave a short synopsis of the waterfall and agile SDLC models. Remember that the waterfall model is best for well defined, stable environments and requirements. The agile model, on the other hand, is best when the user’s needs change constantly.
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