Agile, Lean, Iterative, Prototyping, DevOps, Spiral, or V-model? The SDLC, or system development life cycle, is the industry-standard technique to manage the phases of an engineering project. Consider it the software development and other IT endeavors' equivalent of the scientific process. There are many different types of SDLCs that differ in their focus, level of detail, and time frame.
SDLCs can be categorized by their level of detail. Top-down approaches such as program management are high-level projects that define the need for a new product or service and identify appropriate candidates to meet that need. They typically cover the entire lifecycle of a product from concept through deployment. Middle-out approaches such as project planning are detailed plans that describe each phase of a new product's development in great detail from initial ideas to production ready code. Bottom-up approaches such as exploratory programming involve generating ideas and concepts for new products or features and then coding them immediately after they are thought of without first going through the formal design and development processes. These approaches are often used when there is no clear direction on how to proceed with a project or if more options are needed to find the best solution.
There are also dynamic approaches that change over time based on the needs of the project or organization.
What is the Life Cycle of Systems Development? —WhatIs.com definition The systems development life cycle (SDLC) is a project management conceptual model that defines the processes involved in an information system development project, from early feasibility studies to application maintenance. It was first published by NIST in 1993.
It has four phases: initiation, planning, implementation, and termination. Each phase includes several tasks that may be executed by different people at different locations using various tools.
The SDLC can be used as a guide for developing any type of information system, including web applications, mobile apps, desktop apps, voice-enabled apps, and more. It is also useful for determining appropriate methods for implementing an information system within an organization.
The systems development life cycle (SDLC) is a project management conceptual model that defines the processes involved in an information system development project, from early feasibility studies to application maintenance. SDLC may be used with both technical and non-technical systems. The term "systems development life cycle" was first used by IBM in 1972.
The systems development life cycle models the various stages of a software project through the use of diagrams to explain the relationships between these stages. These diagrams are called "lifecycle maps". A lifecycle map shows the dependencies among the project's activities. For example, if building a database is required for a project, then it would be represented on the diagram as dependent on the "Database Design" stage. If coding begins before the design is complete, then it could cause problems later when trying to implement the program. One solution would be to put a reserve on the budget to cover possible changes to the plan.
A systems developer uses this knowledge to ensure that projects remain on schedule and within budget. The systems development life cycle provides a clear picture of where each project activity lies in relation to the rest of the project. This allows developers to identify potential problem areas early in the project so they can be addressed correctly and efficiently.
SDLC models were first developed in the 1960s to handle large government projects such as the Apollo space missions.
The standard system life cycle splits the project into phases, each with its own set of deliverables, such as documentation or computer programs. This is referred to as the Systems Development Life Cycle (SDLC). The latter guarantees that users and their management are involved in the development of the system. It also ensures quality by dividing the project into manageable pieces that can be completed within a specified time frame.
Phases of the SDLC include requirements definition, design, coding, testing, implementation, deployment, and maintenance/support. Requirements definition starts the process by identifying what needs to be built and by defining its purpose. This phase also includes determining who will use the system, considering their needs and expectations. The next step is to design the system, focusing on how it will work rather than what it will look like. Designing takes into account all aspects of the system including its functionality, structure, and interface. Coding is the process of converting the design into actual software. Testing is needed to ensure that the code functions properly before it is released into production. Implementation involves putting the software into use by users. Deployment means making the new system available to the public. Maintenance/Support includes any necessary updates or changes to the system's software or documentation.
The SDLC is not fixed in stone; it may be modified to fit the needs of the project. For example, if additional features are required after launch, they can be added during maintenance/support phases of the project.
SDLC models, which stand for Software Development Life Cycle models, are one of the fundamental concepts of the software development process. There is no such thing as a single SDLC model. They are classified into three major groupings, each with its own set of strengths and drawbacks. These are the Waterfall Model, the Agile Model, and the Spiral Model.
The Waterfall Model is the most popular SDLC model. In this model, the entire project is planned up front in meticulous detail, starting with the highest-level requirements and working down to the lowest-level tasks. Each phase of the project is completed before moving on to the next phase. At the end of the project, all the phases are rolled out simultaneously. This model is most suitable for projects that can be divided up into discrete steps or milestones that can be measured accurately against a fixed deadline. It is also useful if there is high visibility into each stage of the project, so that progress can be monitored and any problems identified early on.
The Agile Model was developed to address the shortcomings of the Waterfall Model. Rather than following a rigid plan from start to finish, projects using this model follow a cycle of planning, building, testing, and improving that fits around the needs of the project. The key aspect of agility is that it allows changes to be made quickly when needed.
The three basic goals of a systems development lifecycle (SDLC) are to ensure that high-quality systems are provided, to provide strong management controls over the projects, and to maximize the efficiency of the systems workforce. These goals are often referred to as "the holy grail of SDLCs" because no single tool or process can be considered adequate to meet all of them.
The objectives of an effective systems development lifecycle are:
These objectives may not apply to every systems development effort, but they should be considered when planning any project, regardless of its nature (i.e., new system or modification/enhancement to an existing one).
It is important to understand that while all projects aim at producing a successful outcome, not all succeed. Some projects fail for various reasons ranging from simple mismanagement to lack of resources.