CAD-Reviewer-ni-gilberto PDF

**[Data flow Diagram]** -- Provides a **graphical representation of the system** that aims to be accessible to computer specialist and non-specialist users. It describes the process that are **involved in a system transfer data** from the input to the file storage and reports generation. **[Entitie...

**[Data flow Diagram]** -- Provides a **graphical representation of the system** that aims to be accessible to computer specialist and non-specialist users. It describes the process that are **involved in a system transfer data** from the input to the file storage and reports generation. **[Entities]** -- Entities represent people, organization, or other things that interact with the system, i.e. "entities that are outside the system," that is they are part of a process, but external to the information system. **[Processes]** -- are the actions that **directly change the data**. Whenever an action takes place, a new output is formed based on that action. Typical process includes calculations, data sorting or set of specific rules that a business may follow. **[Data Flow]** - Data flow is the lines with arrows that are used to mark where the data flows. As external entities create processes and interact with data stores, data flow lines map out these inputs and outputs\ **[Data Stores]** - Datastores are files or storage areas that contain information that can be called on at a later date. They typically appear as database tables or spreadsheets. Like processes, data stores receive simple labels explaining their purpose or order. **[Rules of Data Flow]** **1**. **[Data cannot flow between two entities]**. -- Data flow must be from entity to a process or a process to an entity. There can be multiple data flows between one entity and a process. **2. [Data cannot flow between two data stores]** - Data flow must be from data store to a process or a process to an data store. Data flow can occur from one data store to many process **3. [Data cannot flow directly from entity to data store]** - Data Flow from entity must be processed by a process before going to data store and vice versa. - Miracle - Black hole - Gray hole - No data - Entity to entity - Entity to data store - Data store to data store **[Application of DFD's]** **1. [Software Engineering ]**- data flow diagramming provides structure before coding begins and is one of the most helpful application architecture diagrams **2. [Agile Development] -** Allows developers to better visualize requirements as they build on existing work **3. [Business Analysis ]**- these diagrams provide a framework to examine existing systems and remove inefficiencies **[Levels of Data Flow Diagram]** **1. [Level 0 Context Diagram ]** - Process represents the entire system - High Level I/O - No Data Store **2. [Level 1 Overview Diagram]** - Use 4 Elements - Limit 9-10 Process **3. [Level 2 Overview Diagram]** - Breakdown the Process - Add more Detailed data store **[Use Case Diagram]** Use case diagram is a behavioral **UML diagram** type and frequently used to analyze various systems. USE CASE DIAGRAM enables you to visualize the different types of roles in a system and how those roles interact with the system. **[UML]** - **Unified Modeling Language**, is a standardized modeling language consisting of an **integrated set of diagrams**, developed to help system and software developers for specifying, visualizing, constructing, and documenting the artifacts of software systems, as well as for business modeling and other non-software systems. **[Use case Diagram Elements ]** **1. [System ]**- The **SYSTEM** is used to define the scope of the use case and drawn as a rectangle. This an optional element but useful when you're visualizing large systems. **2. [Actor]** - **ACTOR** in a use case diagram is any entity that performs a role in one given system. This could be a person, organization or an external system and usually drawn like skeleton shown below. **3. [Use Case]** - A **USE CASE** represents a function or an action within the system. It's drawn as an oval and named with the function. **4. [Communication Link] -- Communication Link** use to show the connection of an actor to a use case by a solid line. Actors may be connected to use cases by associations, indicating that the actor and the use case communicate. **5. [Relationship ]**-- **Relationship** Illustrate relationships between an actor and a use case with a simple line. For relationships among use cases, use arrows labeled either \"\\"or \"\\" **[When to use INCLUDE]** - The base use case is INCOMPLETE without the included use case. - The included use case is mandatory process and not optional. **[When to use EXCLUDE]** - The extending use case is usually Conditional process - The main use case can work without the extending use case. **[Relationship Rules]** - The 2 or more base use case can be included 1 sub use case. - Relationship can be only used to Main use to sub use case. - Actor should not be able to access the included or extended use-case **[Electrical & Electronic Simulation]** **1. [Capacitor] --** Capacitor is a passive electrical component that stores energy in the form of electric field. It is made from metal plates with dielectric between them. **2. [Light Emitting diode] -** a light-emitting diode a semiconductor diode which glows when a voltage is applied. **3. [Resistor] --** Resistor is a passive electrical component that introduces resistance (opposes the flow of current in it) in a circuit to reduce current, divide voltage or for biasing other active components. **4. [Switch] -** Switch is an electrical component that is used for breaking or making a circuit. They are used for stopping the current flow in a circuit or start its conduction. **5. [Electrical Wires] --** it is the symbol that is used to represent a wire. **6. [Connected Wires] --** This symbol represents the wire connected crossing. **7. [Not Connected Wires]** -- This Symbol shows that wires are not connected on crossing.