Diagram

# Diagram

Overview

Discussion

Encyclopedia

A diagram is a two-dimensional geometric
2D geometric model
A 2D geometric model is a geometric model of an object as two-dimensional figure, usually on the Euclidean or Cartesian plane.Even though all material objects are three-dimensional, a 2D geometric model is often adequate for certain flat objects, such as paper cut-outs and machine parts made of...

symbolic representation
Depiction
Depiction is meaning conveyed through pictures. Basically, a picture maps an object to a two-dimensional scheme or picture plane. Pictures are made with various materials and techniques, such as painting, drawing, or prints mosaics, tapestries, stained glass, and collages of unusual and disparate...

of information
Information
Information in its most restricted technical sense is a message or collection of messages that consists of an ordered sequence of symbols, or it is the meaning that can be interpreted from such a message or collection of messages. Information can be recorded or transmitted. It can be recorded as...

according to some visualization
Illustration
An illustration is a displayed visualization form presented as a drawing, painting, photograph or other work of art that is created to elucidate or dictate sensual information by providing a visual representation graphically.- Early history :The earliest forms of illustration were prehistoric...

technique. Sometimes, the technique uses a three-dimensional
Three-dimensional space
Three-dimensional space is a geometric 3-parameters model of the physical universe in which we live. These three dimensions are commonly called length, width, and depth , although any three directions can be chosen, provided that they do not lie in the same plane.In physics and mathematics, a...

visualization which is then projected
Graphical projection
Graphical projection is a protocol by which an image of a three-dimensional object is projected onto a planar surface without the aid of mathematical calculation, used in technical drawing.- Overview :...

onto the two-dimensional surface. The word graph
Graphics
Graphics are visual presentations on some surface, such as a wall, canvas, computer screen, paper, or stone to brand, inform, illustrate, or entertain. Examples are photographs, drawings, Line Art, graphs, diagrams, typography, numbers, symbols, geometric designs, maps, engineering drawings,or...

is sometimes used as a synonym
Synonym
Synonyms are different words with almost identical or similar meanings. Words that are synonyms are said to be synonymous, and the state of being a synonym is called synonymy. The word comes from Ancient Greek syn and onoma . The words car and automobile are synonyms...

for diagram.

Today, most diagrams are generated using diagramming software
Diagramming software
Diagramming software is a computer program that is used to produce graphical diagrams. Diagrams are used in software and business to represent dataflows, workflows and software architecture.- Flowchart :* ARIS Express * Creately...

.

## Overview

A diagram is a 2D geometric symbolic representation
Depiction
Depiction is meaning conveyed through pictures. Basically, a picture maps an object to a two-dimensional scheme or picture plane. Pictures are made with various materials and techniques, such as painting, drawing, or prints mosaics, tapestries, stained glass, and collages of unusual and disparate...

of information
Information
Information in its most restricted technical sense is a message or collection of messages that consists of an ordered sequence of symbols, or it is the meaning that can be interpreted from such a message or collection of messages. Information can be recorded or transmitted. It can be recorded as...

according to some visualization
Illustration
An illustration is a displayed visualization form presented as a drawing, painting, photograph or other work of art that is created to elucidate or dictate sensual information by providing a visual representation graphically.- Early history :The earliest forms of illustration were prehistoric...

technique. Sometimes, the technique uses a 3D
Three-dimensional space
Three-dimensional space is a geometric 3-parameters model of the physical universe in which we live. These three dimensions are commonly called length, width, and depth , although any three directions can be chosen, provided that they do not lie in the same plane.In physics and mathematics, a...

visualization which is then projected
3D projection
3D projection is any method of mapping three-dimensional points to a two-dimensional plane. As most current methods for displaying graphical data are based on planar two-dimensional media, the use of this type of projection is widespread, especially in computer graphics, engineering and drafting.-...

onto the 2D surface. The term diagram in common sense can have two meanings.
• visual information device : Like the term "illustration
Illustration
An illustration is a displayed visualization form presented as a drawing, painting, photograph or other work of art that is created to elucidate or dictate sensual information by providing a visual representation graphically.- Early history :The earliest forms of illustration were prehistoric...

" the diagram is used as a collective term standing for the whole class of technical genres, including graphs
Graphics
Graphics are visual presentations on some surface, such as a wall, canvas, computer screen, paper, or stone to brand, inform, illustrate, or entertain. Examples are photographs, drawings, Line Art, graphs, diagrams, typography, numbers, symbols, geometric designs, maps, engineering drawings,or...

, technical drawings and tables
Table (information)
A table is a means of arranging data in rows and columns.Production % of goalNorth 4087102%South 4093110% The use of tables is pervasive throughout all communication, research and data analysis. Tables appear in print media, handwritten notes, computer software, architectural...

.
• specific kind of visual display : This is only the genre, that show qualitative data with shapes that are connected by lines, arrows, or other visual links.

In science the term is used in both ways. For example Anderson (1997) stated more generally: "diagrams are pictorial, yet abstract, representations of information, and map
Map
A map is a visual representation of an area—a symbolic depiction highlighting relationships between elements of that space such as objects, regions, and themes....

s, line graph
Line graph
In graph theory, the line graph L of undirected graph G is another graph L that represents the adjacencies between edges of G...

s, bar chart
Bar chart
A bar chart or bar graph is a chart with rectangular bars with lengths proportional to the values that they represent. The bars can be plotted vertically or horizontally....

s, engineering
Engineering
Engineering is the discipline, art, skill and profession of acquiring and applying scientific, mathematical, economic, social, and practical knowledge, in order to design and build structures, machines, devices, systems, materials and processes that safely realize improvements to the lives of...

blueprint
Blueprint
A blueprint is a type of paper-based reproduction usually of a technical drawing, documenting an architecture or an engineering design. More generally, the term "blueprint" has come to be used to refer to any detailed plan....

s, and architect
Architect
An architect is a person trained in the planning, design and oversight of the construction of buildings. To practice architecture means to offer or render services in connection with the design and construction of a building, or group of buildings and the space within the site surrounding the...

s' sketch
Sketch (drawing)
A sketch is a rapidly executed freehand drawing that is not usually intended as a finished work...

es are all examples of diagrams, whereas photographs and video are not". On the other hand Lowe (1993) defined diagrams as specifically "abstract graphic portrayals of the subject matter they represent".

In the specific sense diagrams and charts contrast computer graphics
Computer graphics
Computer graphics are graphics created using computers and, more generally, the representation and manipulation of image data by a computer with help from specialized software and hardware....

, technical illustrations, infographics, maps, and technical drawing
Technical drawing
Technical drawing, also known as drafting or draughting, is the act and discipline of composing plans that visually communicate how something functions or has to be constructed.Drafting is the language of industry....

s, by show "abstract rather than literal
Literal translation
Literal translation, or direct translation, is the rendering of text from one language to another "word-for-word" rather than conveying the sense of the original...

representations of information". The essences of a diagram can be seen as:
• a form of visual format
Content format
A content format is an encoded format for converting a specific type of data to displayable information. Content formats are used in recording and transmission to prepare data for observation or interpretation. This includes both analog and digitized content...

ting devices
• a display that do not show quantitative data, but rather relationships and abstract information
• with building blocks such as geometrical shapes connected by lines, arrow
Arrow
An arrow is a shafted projectile that is shot with a bow. It predates recorded history and is common to most cultures.An arrow usually consists of a shaft with an arrowhead attached to the front end, with fletchings and a nock at the other.- History:...

Or in Hall's (1996) words "diagrams are simplified figures, caricatures in a way, intended to convey essential meaning". These simplified figures are often based on set of rules. The basic shape according to White (1984) can be characterized in terms of "elegance, clarity, ease, pattern, simplicity, and validity". The elegance for a start is determined by whether or not the diagram is "the simplest and most fitting solution to a problem".

## Main diagram types

There are at least the following types of diagrams:
• Graph
Graph (mathematics)
In mathematics, a graph is an abstract representation of a set of objects where some pairs of the objects are connected by links. The interconnected objects are represented by mathematical abstractions called vertices, and the links that connect some pairs of vertices are called edges...

-based diagrams: these take a collection of items and relationships between them, and express them by giving each item a 2D position, while the relationships are expressed as connections between the items or overlaps between the items; examples of such techniques:

• Chart
Chart
A chart is a graphical representation of data, in which "the data is represented by symbols, such as bars in a bar chart, lines in a line chart, or slices in a pie chart"...

-like diagram techniques, which display a relationship between two variables that take either discrete
Discrete mathematics
Discrete mathematics is the study of mathematical structures that are fundamentally discrete rather than continuous. In contrast to real numbers that have the property of varying "smoothly", the objects studied in discrete mathematics – such as integers, graphs, and statements in logic – do not...

or a continuous
Continuous function
In mathematics, a continuous function is a function for which, intuitively, "small" changes in the input result in "small" changes in the output. Otherwise, a function is said to be "discontinuous". A continuous function with a continuous inverse function is called "bicontinuous".Continuity of...

ranges of values; examples:

• Other types of diagrams, e.g.,

Thousands of diagram techniques exist. Some more examples follow.

### A–D

A
• Activity diagram
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 can be used to describe the business and operational step-by-step workflows of components in a system...

used in UML
Unified Modeling Language
Unified Modeling Language is a standardized general-purpose modeling language in the field of object-oriented software engineering. The standard is managed, and was created, by the Object Management Group...

and SysML

B
• Bachman diagram
Bachman diagram
Bachman diagrams are diagrams which are used to design the data using a network or relational "logical" model, separating the data model from the way the data is stored in the system. The model is named after database pioneer Charles Bachman, and mostly used in computer software design...

• Booch
Booch method
The Booch method is a technique used in software engineering. It is an object modeling language and methodology that was widely used in object-oriented analysis and design...

– used in software engineering
Software engineering
Software Engineering is the application of a systematic, disciplined, quantifiable approach to the development, operation, and maintenance of software, and the study of these approaches; that is, the application of engineering to software...

• Block diagram
Block diagram
Block diagram is a diagram of a system, in which the principal parts or functions are represented by blocks connected by lines, that show the relationships of the blocks....

• Block Definition Diagram (BDD) used in SysML
• Business & IT Diagram (B&IT)
OBASHI
The OBASHI® methodology provides a framework and method for capturing, illustrating and modeling the relationships, dependencies and dataflows between business and Information technology assets and resources in a business context....

- used in business and IT modelling

C
• Cartogram
Cartogram
A cartogram is a map in which some thematic mapping variable – such as travel time or Gross National Product – is substituted for land area or distance. The geometry or space of the map is distorted in order to convey the information of this alternate variable...

• Category theory diagrams
Diagram (category theory)
In category theory, a branch of mathematics, a diagram is the categorical analogue of an indexed family in set theory. The primary difference is that in the categorical setting one has morphisms. An indexed family of sets is a collection of sets, indexed by a fixed set; equivalently, a function...

• Cause-and-effect diagram
• Circuit diagram
Circuit diagram
A circuit diagram is a simplified conventional graphical representation of an electrical circuit...

• Class diagram
Class diagram
In software engineering, a class diagram in the Unified Modeling Language is a type of static structure diagram that describes the structure of a system by showing the system's classes, their attributes, operations , and the relationships among the classes.- Overview :The class diagram is the main...

– from UML
Unified Modeling Language
Unified Modeling Language is a standardized general-purpose modeling language in the field of object-oriented software engineering. The standard is managed, and was created, by the Object Management Group...

• Collaboration diagram
Communication diagram
A communication diagram in the Unified Modeling Language 2.0, is a simplified version of the UML 1.x collaboration diagram.UML has four types of interaction diagrams:* Sequence diagram* Communication diagram* Interaction overview diagram...

– from UML 1.x
Unified Modeling Language
Unified Modeling Language is a standardized general-purpose modeling language in the field of object-oriented software engineering. The standard is managed, and was created, by the Object Management Group...

• Communication diagram
Communication diagram
A communication diagram in the Unified Modeling Language 2.0, is a simplified version of the UML 1.x collaboration diagram.UML has four types of interaction diagrams:* Sequence diagram* Communication diagram* Interaction overview diagram...

– from UML 2.0
Unified Modeling Language
Unified Modeling Language is a standardized general-purpose modeling language in the field of object-oriented software engineering. The standard is managed, and was created, by the Object Management Group...

• Commutative diagram
Commutative diagram
In mathematics, and especially in category theory, a commutative diagram is a diagram of objects and morphisms such that all directed paths in the diagram with the same start and endpoints lead to the same result by composition...

• Component diagram
Component diagram
In the Unified Modeling Language, a component diagram depicts how components are wired together to form larger components and or software systems.They are used to illustrate the structure of arbitrarily complex systems.- Overview :...

– from UML
Unified Modeling Language
Unified Modeling Language is a standardized general-purpose modeling language in the field of object-oriented software engineering. The standard is managed, and was created, by the Object Management Group...

• Composite structure diagram
Composite structure diagram
Composite structure diagram in the Unified Modeling Language is a type of static structure diagram, that shows the internal structure of a class and the collaborations that this structure makes possible....

– from UML
Unified Modeling Language
Unified Modeling Language is a standardized general-purpose modeling language in the field of object-oriented software engineering. The standard is managed, and was created, by the Object Management Group...

• Concept map
Concept map
For concept maps in generic programming, see Concept .A concept map is a diagram showing the relationships among concepts. It is a graphical tool for organizing and representing knowledge....

• Constellation diagram
Constellation diagram
A constellation diagram is a representation of a signal modulated by a digital modulation scheme such as quadrature amplitude modulation or phase-shift keying. It displays the signal as a two-dimensional scatter diagram in the complex plane at symbol sampling instants...

• Context diagram
• Control flow diagram
Control flow diagram
A control flow diagram is a diagram to describe the control flow of a business process, process or program.Control flow diagrams were developed in the 1950s, and are widely used in multiple engineering disciplines...

• Contour diagram
• Cordier diagram
• Cross functional flowchart

D
• Database model diagram
• Data flow diagram
Data flow diagram
A data flow diagram is a graphical representation of the "flow" of data through an information system, modelling its process aspects. Often they are a preliminary step used to create an overview of the system which can later be elaborated...

• Data structure diagram
Data structure diagram
A Data Structure Diagram is a data model used to describe conceptual data models by providing graphical notations which document entities and their relationships, and the constraints that binds them....

• Dendrogram
Dendrogram
A dendrogram is a tree diagram frequently used to illustrate the arrangement of the clusters produced by hierarchical clustering...

• Dependency diagram
• Deployment diagram
Deployment diagram
A deployment diagram in the Unified Modeling Language models the physical deployment of artifacts on nodes. To describe a web site, for example, a deployment diagram would show what hardware components exist , what software components run on each node , and how...

– from UML
Unified Modeling Language
Unified Modeling Language is a standardized general-purpose modeling language in the field of object-oriented software engineering. The standard is managed, and was created, by the Object Management Group...

• Dot and cross diagram
• Double bubble map - used in education

List of modeling languages

### E–H

E
• Entity-Relationship diagram (ERD)
• Event-driven process chain
Event-driven process chain
An Event-driven Process Chain is a type of flowchart used for business process modelling. EPC's can be used for configuring an enterprise resource planning implementation, and for business process improvement.- Overview :...

• Euler diagram
Euler diagram
An Euler diagram is a diagrammatic means of representing sets and their relationships. The first use of "Eulerian circles" is commonly attributed to Swiss mathematician Leonhard Euler . They are closely related to Venn diagrams....

• Eye diagram - a diagram of a received telecommunications signal
• Express-G
• Extended Functional Flow Block Diagram (EFFBD)

F
• Family tree
Family tree
A family tree, or pedigree chart, is a chart representing family relationships in a conventional tree structure. The more detailed family trees used in medicine, genealogy, and social work are known as genograms.-Family tree representations:...

• Feynman diagram
Feynman diagram
Feynman diagrams are a pictorial representation scheme for the mathematical expressions governing the behavior of subatomic particles, first developed by the Nobel Prize-winning American physicist Richard Feynman, and first introduced in 1948...

• Flow chart
• Flow process chart
Flow process chart
The flow process chart in industrial engineering is a graphical and symbolic representation of the processing activities performed on the work piece.- History :...

• Fusion diagram
• Free body diagram
Free body diagram
A free body diagram, also called a force diagram, is a pictorial representation often used by physicists and engineers to analyze the forces acting on a body of interest. A free body diagram shows all forces of all types acting on this body. Drawing such a diagram can aid in solving for the unknown...

G
• Gantt chart
Gantt chart
A Gantt chart is a type of bar chart that illustrates a project schedule. Gantt charts illustrate the start and finish dates of the terminal elements and summary elements of a project. Terminal elements and summary elements comprise the work breakdown structure of the project. Some Gantt charts...

– shows the timing of tasks or activities (used in project management
Project management
Project management is the discipline of planning, organizing, securing, and managing resources to achieve specific goals. A project is a temporary endeavor with a defined beginning and end , undertaken to meet unique goals and objectives, typically to bring about beneficial change or added value...

)
• Grotrian diagram
Grotrian diagram
A Grotrian diagram or term diagram shows the allowed transitions between the energy levels of atoms. They can be used for one electron and multi electron atoms. They take into account the specific selection rules related to changes in angular momentum of the electron. The diagrams are named after...

• Goodman diagram - shows the fatigue
Fatigue (material)
'In materials science, fatigue is the progressive and localized structural damage that occurs when a material is subjected to cyclic loading. The nominal maximum stress values are less than the ultimate tensile stress limit, and may be below the yield stress limit of the material.Fatigue occurs...

data (example: for a wind turbine
Wind turbine
A wind turbine is a device that converts kinetic energy from the wind into mechanical energy. If the mechanical energy is used to produce electricity, the device may be called a wind generator or wind charger. If the mechanical energy is used to drive machinery, such as for grinding grain or...

H
• Hasse diagram
Hasse diagram
In order theory, a branch of mathematics, a Hasse diagram is a type of mathematical diagram used to represent a finite partially ordered set, in the form of a drawing of its transitive reduction...

• HIPO diagram

### I–L

I
• Internal Block Diagram (IBD) used in SysML
• IDEF0
IDEF0
IDEF0 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.IDEF0 is part of the IDEF family...

• IDEF1 (entity relations)
• Interaction overview diagram
Interaction overview diagram
Interaction Overview Diagram is one of the fourteen types of diagrams of the Unified Modeling Language , which can picture a control flow with nodes that can contain interaction diagrams....

– from UML
Unified Modeling Language
Unified Modeling Language is a standardized general-purpose modeling language in the field of object-oriented software engineering. The standard is managed, and was created, by the Object Management Group...

• Ishikawa diagram
Ishikawa diagram
Ishikawa diagrams are causal diagrams that show the causes of a certain event -- created by Kaoru Ishikawa . Common uses of the Ishikawa diagram are product design and quality defect prevention, to identify potential factors causing an overall effect...

J
• Jackson diagram
Jackson Structured Programming
Jackson Structured Programming or JSP is a method for structured programming based on correspondences between data stream structure and program structure...

K
• Karnaugh map
Karnaugh map
The Karnaugh map , Maurice Karnaugh's 1953 refinement of Edward Veitch's 1952 Veitch diagram, is a method to simplify Boolean algebra expressions...

• Kinematic diagram
Kinematic diagram
|- style="text-align:center;"| || |- style="text-align:center;"| PUMA robot || and its kinematic diagramKinematic diagram or kinematic scheme is diagram of a mechanism or machine that shows its moving parts and their relationships to each other....

L
• Line of balance

### M–P

M
• Martin ERD
• Message Sequence Chart
Message Sequence Chart
A Message Sequence Chart is an interaction diagram from the SDL family very similar to UML's sequence diagram, standardized by the International Telecommunication Union....

• Mind map
Mind map
A mind map is a diagram used to represent words, ideas, tasks, or other items linked to and arranged around a central key word or idea. Especially in British English, the terms spidergram and spidergraph are more common, but they can cause confusion with the term spider diagram used in mathematics...

– used for learning, brainstorming, memory, visual thinking and problem solving

N
• N2
• Nassi–Shneiderman diagram or structogram – a representation for structured programming
Structured programming
Structured programming is a programming paradigm aimed on improving the clarity, quality, and development time of a computer program by making extensive use of subroutines, block structures and for and while loops - in contrast to using simple tests and jumps such as the goto statement which could...

• Nomogram
Nomogram
A nomogram, nomograph, or abac is a graphical calculating device developed by P.E. Elyasberg, a two-dimensional diagram designed to allow the approximate graphical computation of a function: it uses a coordinate system other than Cartesian coordinates...

O
• Object diagram
Object diagram
An object diagram in the Unified Modeling Language , is a diagram that shows a complete or partial view of the structure of a modeled system at a specific time....

– from UML
Unified Modeling Language
Unified Modeling Language is a standardized general-purpose modeling language in the field of object-oriented software engineering. The standard is managed, and was created, by the Object Management Group...

P
• Package diagram
Package diagram
A package diagram in the Unified Modeling Language depicts the dependencies between the packages that make up a model.- Overview :In addition to the standard UML Dependency relationship, there are two special types of dependencies defined between packages:...

from UML
Unified Modeling Language
Unified Modeling Language is a standardized general-purpose modeling language in the field of object-oriented software engineering. The standard is managed, and was created, by the Object Management Group...

and SysML
• Parametric diagram from SysML
• PERT
• Petri net
Petri net
A Petri net is one of several mathematical modeling languages for the description of distributed systems. A Petri net is a directed bipartite graph, in which the nodes represent transitions and places...

– shows the structure of a distributed system as a directed bipartite graph
Bipartite graph
In the mathematical field of graph theory, a bipartite graph is a graph whose vertices can be divided into two disjoint sets U and V such that every edge connects a vertex in U to one in V; that is, U and V are independent sets...

with annotations
• Piping and instrumentation diagram
Piping and instrumentation diagram
A piping and instrumentation diagram/drawing is a diagram in the process industry which shows the piping of the process flow together with the installed equipment and instrumentation.-Contents and Function:...

(P&ID)
• Phase diagram
Phase diagram
A phase diagram in physical chemistry, engineering, mineralogy, and materials science is a type of chart used to show conditions at which thermodynamically distinct phases can occur at equilibrium...

used to present solid/liquid/gas information
• Plant Diagram
• Pressure volume diagram
Pressure volume diagram
A pressure volume diagram is used to describe corresponding changes in volume and pressure in a system...

used to analyse engines
• Pourbaix diagram
Pourbaix diagram
In chemistry, a Pourbaix diagram, also known as a potential/pH diagram, maps out possible stable phases of an aqueous electrochemical system. Predominant ion boundaries are represented by lines. As such a Pourbaix diagram can be read much like a standard phase diagram with a different set of axes...

• Process flow diagram
Process Flow diagram
A process flow diagram is a diagram commonly used in engineering to indicate the general flow of plant processes and equipment.The PFD displays the relationship between major equipment of a plant facility and does not show minor details such as piping details and designations...

or PFD – used in chemical engineering
Chemical engineering
Chemical engineering is the branch of engineering that deals with physical science , and life sciences with mathematics and economics, to the process of converting raw materials or chemicals into more useful or valuable forms...

• Program structure diagram

### R–U

R
• Requirement Diagram Used in SysML
• Rich Picture
Rich picture
Part of the Soft systems methodology, Rich Pictures provide a mechanism for learning about complex or ill-defined problems by drawing detailed representations of them. Typically, rich pictures follow no commonly agreed syntax, usually consist of symbols, sketches or "doodles" and can contain as...

S
• Sankey diagram
Sankey diagram
Sankey diagrams are a specific type of flow diagram, in which the width of the arrows is shown proportionally to the flow quantity. They are typically used to visualize energy or material or cost transfers between processes.-Application:...

- represents material, energy or cost flows with quantity proportional arrows in a process network.
• Sentence diagram
Sentence diagram
In pedagogy, a sentence diagram is a pictorial representation of the grammatical structure of a natural-language sentence. A sentence diagram is a form of a parse tree.- History :...

-- represents the grammatical
Grammar
In linguistics, grammar is the set of structural rules that govern the composition of clauses, phrases, and words in any given natural language. The term refers also to the study of such rules, and this field includes morphology, syntax, and phonology, often complemented by phonetics, semantics,...

structure of a natural language
Natural language
In the philosophy of language, a natural language is any language which arises in an unpremeditated fashion as the result of the innate facility for language possessed by the human intellect. A natural language is typically used for communication, and may be spoken, signed, or written...

sentence.
• Sequence diagram
Sequence diagram
A sequence diagram in Unified Modeling Language is a kind of interaction diagram that shows how processes operate with one another and in what order. It is a construct of a Message Sequence Chart....

from UML
Unified Modeling Language
Unified Modeling Language is a standardized general-purpose modeling language in the field of object-oriented software engineering. The standard is managed, and was created, by the Object Management Group...

and SysML
• SDL/GR diagram – Specification and Description Language. SDL is a formal language
Formal language
A formal language is a set of words—that is, finite strings of letters, symbols, or tokens that are defined in the language. The set from which these letters are taken is the alphabet over which the language is defined. A formal language is often defined by means of a formal grammar...

used in computer science
Computer science
Computer science or computing science is the study of the theoretical foundations of information and computation and of practical techniques for their implementation and application in computer systems...

.
• Smith chart
Smith chart
The Smith chart, invented by Phillip H. Smith , is a graphical aid or nomogram designed for electrical and electronics engineers specializing in radio frequency engineering to assist in solving problems with transmission lines and matching circuits...

• Spider chart
A radar chart is a graphical method of displaying multivariate data in the form of a two-dimensional chart of three or more quantitative variables represented on axes starting from the same point...

• Spray diagram
• SSADM – Structured Systems Analysis and Design Methodology (used in software engineering
Software engineering
Software Engineering is the application of a systematic, disciplined, quantifiable approach to the development, operation, and maintenance of software, and the study of these approaches; that is, the application of engineering to software...

)
• Star chart
Star chart
A star chart is a map of the night sky. Astronomers divide these into grids to use them more easily. They are used to identify and locate astronomical objects such as stars, constellations and galaxies. They have been used for human navigation since time immemorial...

/Celestial sphere
Celestial sphere
In astronomy and navigation, the celestial sphere is an imaginary sphere of arbitrarily large radius, concentric with the Earth and rotating upon the same axis. All objects in the sky can be thought of as projected upon the celestial sphere. Projected upward from Earth's equator and poles are the...

• State diagram
State diagram
A state diagram is a type of diagram used in computer science and related fields to describe the behavior of systems. State diagrams require that the system described is composed of a finite number of states; sometimes, this is indeed the case, while at other times this is a reasonable abstraction...

are used for state machines in software engineering
• Swim lane
Swim lane
A swim lane is a visual element used in process flow diagrams, or flowcharts, that visually distinguishes responsibilities for sub-processes of a business process. Swim lanes may be arranged either horizontally or vertically...

• Systems Biology Graphical Notation
Systems Biology Graphical Notation
The Systems Biology Graphical Notation is a standard graphical representation crafted over several years by a community of biochemists, modelers and computer scientists....

- a graphical notation used in diagrams of biochemical and cellular processes studied in Systems biology
Systems biology
Systems biology is a term used to describe a number of trends in bioscience research, and a movement which draws on those trends. Proponents describe systems biology as a biology-based inter-disciplinary study field that focuses on complex interactions in biological systems, claiming that it uses...

• System context diagram
System context diagram
A System Context Diagram in software engineering and systems engineering is a diagram that represents the actors outside a system that could interact with that system. This diagram is the highest level view of a system. It is similar to a Block diagram...

• System structure
• Systematic layout planning
Systematic layout planning
The systematic layout planning is a tool used to arrange a workplace in a plant by locating two areas with high frequency and logical relationships close to each other...

T
• Timing Diagram: Digital Timing Diagram
Digital Timing Diagram
A Digital timing diagram is a representation of a set of signals in the time domain. A timing diagram can contain many rows, usually one of them being the clock. It is a tool that is ubiquitous in digital electronics, hardware debugging, and digital communications...

• Timing Diagram: UML Timing Diagram
UML Timing Diagram
A timing diagram in the Unified Modeling Language 2.0 is a specific type of interaction diagram, where the focus is on timing constraints.Timing diagrams are used to explore the behaviors of objects throughout a given period of time. A timing diagram is a special form of a sequence diagram...

• TQM Diagram

U
• UML diagram – Unified Modeling Language (used in software engineering
Software engineering
Software Engineering is the application of a systematic, disciplined, quantifiable approach to the development, operation, and maintenance of software, and the study of these approaches; that is, the application of engineering to software...

)
• Use case diagram
Use case
In software engineering and systems engineering, a use case is a description of steps or actions between a user and a software system which leads the user towards something useful...

– from UML
Unified Modeling Language
Unified Modeling Language is a standardized general-purpose modeling language in the field of object-oriented software engineering. The standard is managed, and was created, by the Object Management Group...

and SysML

### V–Z

V
• Value Stream Mapping
Value Stream Mapping
Value stream mapping is a lean manufacturing technique used to analyze and design the flow of materials and information required to bring a product or service to a consumer. At Toyota, where the technique originated, it is known as "material and information flow mapping"...

• Venn diagram
Venn diagram
Venn diagrams or set diagrams are diagrams that show all possible logical relations between a finite collection of sets . Venn diagrams were conceived around 1880 by John Venn...

• Voronoi diagram
Voronoi diagram
In mathematics, a Voronoi diagram is a special kind of decomposition of a given space, e.g., a metric space, determined by distances to a specified family of objects in the space...

W
• Warnier-Orr

Y
• Yourdon-Coad – see Edward Yourdon
Edward Yourdon
Edward Nash Yourdon is an American software engineer, computer consultant, author and lecturer, and pioneer in the software engineering methodology...

, used in software engineering
Software engineering
Software Engineering is the application of a systematic, disciplined, quantifiable approach to the development, operation, and maintenance of software, and the study of these approaches; that is, the application of engineering to software...

• Chart
Chart
A chart is a graphical representation of data, in which "the data is represented by symbols, such as bars in a bar chart, lines in a line chart, or slices in a pie chart"...

• Diagramming Software
Diagramming software
Diagramming software is a computer program that is used to produce graphical diagrams. Diagrams are used in software and business to represent dataflows, workflows and software architecture.- Flowchart :* ARIS Express * Creately...

• Diagrammatic reasoning
Diagrammatic reasoning
Diagrammatic reasoning is reasoning by means of visual representations. The study of diagrammatic reasoning is about the understanding of concepts and ideas, visualized with the use of diagrams and imagery instead of by linguistic or algebraic means....

• List of graphical methods
• Mathematical diagram
Mathematical diagram
Mathematical diagrams are diagrams in the field of mathematics, and diagrams using mathematics such as charts and graphs, that are mainly designed to convey mathematical relationships, for example, comparisons over time.- Argand diagram :...

• Plot (graphics)
Plot (graphics)
A plot is a graphical technique for representing a data set, usually as a graph showing the relationship between two or more variables. The plot can be drawn by hand or by a mechanical or electronic plotter. Graphs are a visual representation of the relationship between variables, very useful for...

• commons:Specific diagram types - gallery of many diagram types.
• commons:Commons:Diagram resources