System Flow Chart
A system flow chart is a diagrammatic representation to explain how a system works. Diagrammatic representations are easier to understand than lengthy text.
System flow chat is one of the major tools of the system analyst to show an overview of the processing in a complete system.
Learn more on System Development Cycle;
Entity- Relation ER Diagram
Entity Relation Diagram shows data in terms of the entities and relationships described by the data. An entity is anything in a real-world system that can be uniquely identified. It can be a set of person, place, objects, events, or even concepts.
For example, students can be an entity. Every entity instance, that is every student can be recognized by their registration number or citizenship number among other students.
A context diagram is a diagram that represents the actors outside a system that could interact with the system it represents the system as a whole and its inputs and outputs form or to external factors.
It is a useful system design to represent external factors interacting with the system itself so that system requirements and constraints can be studied very easily.
It is also used to document the scope of a system. The symbol used in a context diagram is tabulated below.
Learn more on Waterfall Design Model;
Data Flow Diagram (DFD)
Data Flow Diagram (DFD is a tool that describes the flow of data through a system and the work or processing performed by that system.
It shows the flow of data from external entities into the system, how the data moves from one process to another, and its logical storage. Before drawing DFD. It is a good practice to draw a context diagram.
UML (Unified Modeling Language)
UML stands for Unified Modeling Language. It is a slandered language for specifying, visualizing, constructing, and documenting the software systems, as well as for business modeling.
UML is very successful. Such as Microsoft, Oracle, etc.
A use case is the set of scenarios that describes an interaction between a user and a system. It is a comparatively easier type of UML diagram to draw. It displays the relationship between actors and use cases.
The two main components of a use case diagram are use cases and actors.