Software Development Life Cycle (SDLC)
SDLC is a process that creates a structure of development of software. There are different phases within SDLC, and each phase has its own different activity. It makes development team able to design, create and deliver a high-quality product.
SDLC describes various phases of software development and the order of execution of phases. Each phase requires deliverable from the previous phase in a life cycle of software development. Requirements are translated into design, design into development and development into testing, after testing it is given to the client.
Let's see all phases in detail.>
Different phases of the software development cycle
1. Requirement Phase
This is the most crucial phase of software development life cycle for the developing team as well as for the project manager. During this phase, the client states requirements, specifications, expectations and any other special requirement related to the product or software. All these are gathered by the business manager or project manager or analyst of the service providing company.
Requirement includes how the product will be used and who will use the product to determine the load of operations. All information gathered from this phase is critical to developing the product as per the customer requirements.
2. Design Phase
Design phase includes a detailed analysis of new software according to the requirement phase. This is the high priority phase in the development life cycle of a system because the logical designing of the system is converted into physical designing. The output of requirement phase is a collection of things that are required and design phase gives the way to accomplish these requirements. The decision of all required essential tools such as programming language like Java, .NET, PHP; database like Oracle, MySQL, a combination of hardware and software to provide a platform on which software can run without any problem is taken in this phase.
There are several techniques and tools such as data flow diagrams, flowcharts, decision tables and decision trees, Data dictionary, and the structured dictionary are used for describing the system design.
3. Build /Development Phase
After the successful completion of requirement and design phase, the next step is to implement the design into the development of a software system. In this phase, work is divided into small units, and coding starts by the team of developers according to the design discussed in the previous phase and according to the requirements of client discussed in requirement phase to produce the desired result.
Front-end developers develop easy and attractive GUI and necessary interfaces to interact with back-end operations and back-end developers do back-end coding according to the required operations. All is done according to the procedure and guidelines demonstrated by the project manager.
Since, this is the coding phase it takes the longest time and more focused approach for the developer in the software development life cycle.
4. Testing Phase
Testing is the last step of completing software system. In this phase, after getting the developed GUI and back-end combination, it is tested against the requirements stated in the requirement phase. Testing determines whether the software is actually giving the result as per the requirements addressed in the requirement phase or not. Development team makes a test plan to start the test. This test plan includes all types of essential testing such as integration testing, unit testing, acceptance testing, and system testing. Non-functional testing is also done in this phase.
If there are any defects in the software, or it is not working as per expectations, then testing team gives information to the development team in detail about the issue. If it is a valid defect or worth to sort out, it will be fixed and development team replaces it with the new one and it also needs to be verified.
5. Deployment/ Deliver Phase
When software testing is completed with satisfying result and there are no remaining issues in the working of software, it is delivered to the customer for their use.
As soon as customers receive the product, they are recommended first to do the beta testing. In beta testing, customer can require any changes which are not present in the software but mentioned in the requirement document or any other GUI changes to make it more user-friendly. Besides this, if any type of defect is encountered while a customer using the software; it will be informed to the development team of that particular software to sort out the problem. If it is a severe issue, then the development team solves it in a short time otherwise, if it is less severe, then it will wait for the next version.
After the solution of all type of bugs and changes, software finally deployed to the end user.
The maintenance phase is the last and long-lasting phase of SDLC because it is the process which continues till the software's life cycle comes to an end. When a customer starts using software, then actual problems start to occur, and at that time there's a need to solve these problems. This phase also includes making changes in hardware and software to maintain its operational effectiveness like to improve its performance, enhance security features and according to customer's requirements with upcoming time. This process to take care of product time to time is called maintenance.
"So, all these are six phases of software development life cycle (SDLC) under which the process of development of software takes place. All are compulsory phases without any one of the development cannot be possible because development continues for the lifetime of software with maintenance phase".