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Data Flow Diagram
A data-flow diagram is a way of representing a flow of data through a process or a system (usually an information system). The DFD also provides information about the outputs and inputs of each entity and the process itself. A data-flow diagram has no control are no decision rules and no loops. Specific operations based on the data can be represented by a flowchart. There are several notations for displaying data-flow diagrams. The notation presented above was described in 1979 by Tom DeMarco as part of structured analysis. For each data flow, at least one of the endpoints (source and / or destination) must exist in a process. The refined representation of a process can be done in another data-flow diagram, which subdivides this process into sub-processes. The data-flow diagram is a tool that is part of structured analysis and data modeling. When using UML, the activity diagram typically takes over the role of the data-flow diagram. A special form of data-flow plan is a site ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Activity Diagram
Activity diagrams are graphical representations of workflows of stepwise activities and actions with support for choice, iteration and concurrency. In the Unified Modeling Language, activity diagrams are intended to model both computational and organizational processes (i.e., workflows), as well as the data flows intersecting with the related activities. Although activity diagrams primarily show the overall flow of control, they can also include elements showing the flow of data between activities through one or more data stores. Construction Activity diagrams are constructed from a limited number of shapes, connected with arrows. The most important shape types: * ''ellipses'' represent ''actions''; * ''diamonds'' represent ''decisions''; * ''bars'' represent the start (''split'') or end (''join'') of concurrent activities; * a ''black circle'' represents the start (''initial node'') of the workflow; * an ''encircled black circle'' represents the end (''final node''). Arrows run ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
System Context Diagram
A system context diagram (SCD) in engineering is a diagram that defines the boundary between the system, or part of a system, and its environment, showing the entities that interact with it. This diagram is a high level view of a system. It is similar to a block diagram. Overview System context diagrams show a system, as a whole and its inputs and outputs from/to external factors. According to Kossiakoff and Sweet (2011):Alexander Kossiakoff, William N. Sweet (2011). ''Systems Engineering: Principles and Practices'' p. 266 System context diagrams are used early in a project to get agreement on the scope under investigation. Context diagrams are typically included in a requirements document. These diagrams must be read by all project stakeholders and thus should be written in plain language, so the stakeholders can understand items within the document. Building blocks Context diagrams can be developed with the use of two types of building blocks: * ''Entities (Actors)'': l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Structure Chart
A structure chart (SC) in software engineering and organizational theory is a chart which shows the breakdown of a system to its lowest manageable levels.IRS (2008) "Configuration Management" In: ''IRS Resources Part 2. Information Technology Chapter 27. Configuration Management''. Accessed aIRS.GOV14 November 2008. No longer online 8 November 2009. They are used in structured programming to arrange program modules into a tree. Each module is represented by a box, which contains the module's name. The tree structure visualizes the relationships between modules. Overview A structure chart is a top-down modular design tool, constructed of squares representing the different modules in the system, and lines that connect them. The lines represent the connection and or ownership between activities and subactivities as they are used in organization charts.H. Fujita & V. Gruhn (2004). ''New Trends in Software Methodologies, Tools and Techniques''. Page 6. In structured analysis str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Structured Analysis And Design Technique
Structured analysis and design technique (SADT) is a systems engineering and software engineering methodology for describing systems as a hierarchy of functions. SADT is a structured analysis modelling language, which uses two types of diagrams: activity models and data models. It was developed in the late 1960s by Douglas T. Ross, and was formalized and published as IDEF0 in 1981. Overview Structured analysis and design technique (SADT) is a diagrammatic notation designed specifically to help people describe and understand systems.D. Marca, C. McGowan, Structured Analysis and Design Technique, McGraw-Hill, 1987, It offers building blocks to represent entities and activities, and a variety of arrows to relate boxes. These boxes and arrows have an associated informal semantics.John Mylopoulos (2004)Conceptual Modelling III. Structured Analysis and Design Technique (SADT) Retrieved 21 September 2008. SADT can be used as a functional analysis tool of a given process, using success ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pipeline (software)
In software engineering, a pipeline consists of a chain of processing elements ( processes, threads, coroutines, functions, ''etc.''), arranged so that the output of each element is the input of the next; the name is by analogy to a physical pipeline. Usually some amount of buffering is provided between consecutive elements. The information that flows in these pipelines is often a stream of records, bytes, or bits, and the elements of a pipeline may be called filters; this is also called the pipes and filters design pattern. Connecting elements into a pipeline is analogous to function composition. Narrowly speaking, a pipeline is linear and one-directional, though sometimes the term is applied to more general flows. For example, a primarily one-directional pipeline may have some communication in the other direction, known as a ''return channel'' or ''backchannel,'' as in the lexer hack, or a pipeline may be fully bi-directional. Flows with one-directional tree and directed acyc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IDEF0
IDEF0, a compound acronym ("Icam DEFinition for Function Modeling", where ICAM is an acronym for "Integrated Computer Aided Manufacturing"), is a function modeling methodology for describing manufacturing functions, which offers a functional modeling language for the analysis, development, reengineering and integration of information systems, business processes or software engineering analysis.''Systems Engineering Fundamentals.'' Defense Acquisition University Press, 2001. IDEF0 is part of the family of modeling languages in the field of |
Function Model
In systems engineering, software engineering, and computer science, a function model or functional model is a structured representation of the functions ( activities, actions, processes, operations) within the modeled system or subject area.FIPS Publication 183 released of IDEFØ December 1993 by the Computer Systems Laboratory of the National Institute of Standards and Technology (NIST). 
A function model, similar with the activity model or
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Functional Flow Block Diagram
A functional flow block diagram (FFBD) is a multi-tier, time-sequenced, step-by-step flow diagram of a system’s functional flow. The term "functional" in this context is different from its use in functional programming or in mathematics, where pairing "functional" with "flow" would be ambiguous. Here, "functional flow" pertains to the sequencing of operations, with "flow" arrows expressing dependence on the success of prior operations. FFBDs may also express input and output data dependencies between functional blocks, as shown in figures below, but FFBDs primarily focus on sequencing. The FFBD notation was developed in the 1950s, and is widely used in classical systems engineering. FFBDs are one of the classic business process modeling methodologies, along with flow charts, data flow diagrams, control flow diagrams, Gantt charts, PERT diagrams, and IDEF.Thomas Dufresne & James Martin (2003)"Process Modeling for E-Business". INFS 770 Methods for Information Systems Engineering: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DRAKON
DRAKON is a free and open source algorithmic visual programming and modeling language developed within the Buran space project following ergonomic design principles. The language provides a uniform way to represent flowcharts of any complexity that are easy to read and understand. The DRAKON Editor, which was released in September 2011, is an implementation of the language available in the public domain. It can be used for creating documentation, or for creating visual programs that can be converted to source code in other languages. Unlike UML's philosophy, DRAKON's language philosophy is based on being augmented if needed, by using a hybrid language, which can be illustrated as "incrustating code snippets from text language used into shape DRAKON requires". This way, DRAKON always remains a simple visual language that can be used as an augmentation for a programmer who is interested in making their own project code easier to support or other long-term needs for exampl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Directed Acyclic Graph
In mathematics, particularly graph theory, and computer science, a directed acyclic graph (DAG) is a directed graph with no directed cycles. That is, it consists of vertices and edges (also called ''arcs''), with each edge directed from one vertex to another, such that following those directions will never form a closed loop. A directed graph is a DAG if and only if it can be topologically ordered, by arranging the vertices as a linear ordering that is consistent with all edge directions. DAGs have numerous scientific and computational applications, ranging from biology (evolution, family trees, epidemiology) to information science (citation networks) to computation (scheduling). Directed acyclic graphs are sometimes instead called acyclic directed graphs or acyclic digraphs. Definitions A graph is formed by vertices and by edges connecting pairs of vertices, where the vertices can be any kind of object that is connected in pairs by edges. In the case of a directed graph, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dataflow
In computing, dataflow is a broad concept, which has various meanings depending on the application and context. In the context of software architecture, data flow relates to stream processing or reactive programming. Software architecture Dataflow computing is a software paradigm based on the idea of representing computations as a directed graph, where nodes are computations and data flow along the edges. Dataflow can also be called stream processing or reactive programming. There have been multiple data-flow/stream processing languages of various forms (see Stream processing). Data-flow hardware (see Dataflow architecture) is an alternative to the classic von Neumann architecture. The most obvious example of data-flow programming is the subset known as reactive programming with spreadsheets. As a user enters new values, they are instantly transmitted to the next logical "actor" or formula for calculation. Distributed data flows have also been proposed as a programming abstrac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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