In this article, we want to tell you about the software development life cycle. It is a structured process that enables the production of high-quality, low-cost software, in the shortest possible production time. Its task is to produce superior software that meets and exceeds all customer expectations and demands.
Requirements analysis
The software development life cycle begins with the analysis stage, during which process participants discuss the requirements for the final product. The purpose of this stage is to determine the detailed requirements for the system. In addition, it is necessary to make sure that all participants correctly understand the objectives and how each requirement will be implemented in practice.
Testing specialists are also often involved in the discussion, who can describe their point of view and, if necessary, adjust the process at the stage of requirements development.
Depending on the chosen development model, approaches to determining the moment of transition from one stage to another may differ. For example, in the cascade or V-model, the stage of requirements analysis is fixed in the SRS document , the design of which must be completed before moving on to the next stage.
Thus, this stage involves the collection of requirements for the software being developed, their systematization, documentation, analysis, as well as the identification and resolution of conflicts.
Designing
At the design stage (also called the architecture stage), programmers and system architects develop a high-level system design based on requirements. Various technical issues that arise in the design process are discussed with all stakeholders, including the customer. Defines the technologies that will be used in the project, team workload, constraints, time frame and budget. Following the specified requirements, the most appropriate design solutions are selected.
The approved system design determines the list of software components that need to be developed, interaction with third parties, functional characteristics of the program, databases that need to be used and much more. The design is usually fixed in a separate document – the design specification (Design Specification Document (DSD)).
At this stage, the simplification of the visualization process is used as the so-called notations – schematic images of the system being developed. Basics of notation:
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Block diagrams;
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ER-charts;
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UML charts;
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Layouts – for example, a prototype site drawn in Photoshop.
Development and programming
Once the requirements and product design are approved, the transition to the next stage of the life cycle – direct development. This is where the programmers start writing the program code according to the previously defined requirements.
System administrators configure the software environment, front-end programmers develop the user interface of the program and the logic of its interaction with the server.
In addition, programmers write Unit tests to verify the correctness of the code of each component of the system, review the written code, create builds and deploy ready-made software in the software environment. This cycle is repeated until all the requirements are met.
Programming involves four main stages:
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Development of algorithms – in fact, the creation of the logic of the program;
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Writing code source;
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Compilation – conversion into machine code;
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Testing and debugging – this is mainly about unit testing.
