Software Development Model

Software development models

Water fall model

The waterfall model is a simple method that is easy to use and understand. In the water fall method each part of a project must be completed one step after another, the steps for the waterfall method are specifying the requirements, design, implementation, testing, debugging, installation and maintenance. Due to the structure of the model each phase has specific tasks to complete making it easier to structure work this also ensures that the phases don’t overlap. The waterfall method works well for smaller projects where the requirements are well understood.

The water fall method is less suited to larger projects as the requirements may change or there may be an error found during testing that means

Prototypes are often used in addition to or sometimes even in place of design specifications.

RAD is best for creating user interfaces. GUI builders are often called rapid application development tools. Other forms of rapid development are adaptive, agile and spiral.

RAD has 4 phases; (1) the requirements planning phase which uses both system analysis and planning then the entire project team discus the needs, scope, constraints, and system requirements. (2)user design phase users work with system analysts to create to prototypes, the two continue to make prototypes in till they are happy with a working model,(3) construction phase is when the program is made by the programmers and then tested.(4)cutover phase is where the final tasks are completed and the final product is delivered.

Agile methodologies

Are approaches to software development where requirements and solutions change continuously through the development life cycle its best for adaptive planning, evolutionary development, early delivery, and continuous improvement, it also encourages rapid and flexible response to

It is also known as a software development life cycle. Most development processes can be described as agile, waterfall, prototyping, iterative, incremental, spiral development, rapid application development, and extreme programming.

Some people consider a life-cycle model a more general term for a category of methodologies and a software development process a more specific term to refer to a specific process chosen by a specific organization. For example, there are many specific software development processes that fit the spiral life-cycle model.

Adaptive software development

Is a software development process that grew out of rapid application development (RAD). It uses the principle that continuous adaptation of the process to the work at hand is the normal state of affairs.

A DFD shows what kind of information will be input to and output from the system, how the data will advance through the system, and where the data will be stored. It does not show information about process timing or whether processes will operate in sequence or in parallel, unlike a traditional structured flowchart which focuses on control flow, or a UML activity workflow diagram, which presents both control and data flows as a unified

Computer-aided software