Flowchart

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A simple flowchart representing a process for dealing with a non-functioning lamp. LampFlowchart.svg
A simple flowchart representing a process for dealing with a non-functioning lamp.

A flowchart is a type of diagram that represents a workflow or process. A flowchart can also be defined as a diagrammatic representation of an algorithm, a step-by-step approach to solving a task.

Contents

The flowchart shows the steps as boxes of various kinds, and their order by connecting the boxes with arrows. This diagrammatic representation illustrates a solution model to a given problem. Flowcharts are used in analyzing, designing, documenting or managing a process or program in various fields. [1]

Overview

Flowchart of a C-style for loop For-loop-diagram.png
Flowchart of a C-style for loop

Flowcharts are used in designing and documenting simple processes or programs. Like other types of diagrams, they help visualize what is going on and thereby help understand a process, and perhaps also find less-obvious features within the process, like flaws and bottlenecks. There are different types of flowcharts: each type has its own set of boxes and notations. The two most common types of boxes in a flowchart are:

A flowchart is described as "cross-functional" when the chart is divided into different vertical or horizontal parts, to describe the control of different organizational units. A symbol appearing in a particular part is within the control of that organizational unit. A cross-functional flowchart allows the author to correctly locate the responsibility for performing an action or making a decision, and to show the responsibility of each organizational unit for different parts of a single process.

Flowcharts depict certain aspects of processes and are usually complemented by other types of diagram. For instance, Kaoru Ishikawa defined the flowchart as one of the seven basic tools of quality control, next to the histogram, Pareto chart, check sheet, control chart, cause-and-effect diagram, and the scatter diagram. Similarly, in UML, a standard concept-modeling notation used in software development, the activity diagram, which is a type of flowchart, is just one of many different diagram types.

Nassi-Shneiderman diagrams and Drakon-charts are an alternative notation for process flow.

Common alternative names include: flow chart, process flowchart, functional flowchart, process map, process chart, functional process chart, business process model, process model, process flow diagram, work flow diagram, business flow diagram. The terms "flowchart" and "flow chart" are used interchangeably.

The underlying graph structure of a flowchart is a flow graph, which abstracts away node types, their contents and other ancillary information.

History

The first structured method for documenting process flow, the "flow process chart", was introduced by Frank and Lillian Gilbreth in the presentation "Process Charts: First Steps in Finding the One Best Way to do Work", to members of the American Society of Mechanical Engineers (ASME) in 1921. [2] The Gilbreths' tools quickly found their way into industrial engineering curricula. In the early 1930s, an industrial engineer, Allan H. Mogensen began to train business people in the use of some of the tools of industrial engineering at his Work Simplification Conferences in Lake Placid, New York.

Art Spinanger, a 1944 graduate of Mogensen's class, took the tools back to Procter and Gamble where he developed their Deliberate Methods Change Program. Ben S. Graham, another 1944 graduate, Director of Formcraft Engineering at Standard Register Industrial, applied the flow process chart to information processing with his development of the multi-flow process chart, to present multiple documents and their relationships. [3] In 1947, ASME adopted a symbol set derived from Gilbreth's original work as the "ASME Standard: Operation and Flow Process Charts." [4]

Douglas Hartree in 1949 explained that Herman Goldstine and John von Neumann had developed a flowchart (originally, diagram) to plan computer programs. [5] His contemporary account was endorsed by IBM engineers [6] and by Goldstine's personal recollections. [7] The original programming flowcharts of Goldstine and von Neumann can be found in their unpublished report, "Planning and coding of problems for an electronic computing instrument, Part II, Volume 1" (1947), which is reproduced in von Neumann's collected works. [8]

The flowchart became a popular tool for describing computer algorithms, but its popularity decreased in the 1970s, when interactive computer terminals and third-generation programming languages became common tools for computer programming, since algorithms can be expressed more concisely as source code in such languages. Often pseudo-code is used, which uses the common idioms of such languages without strictly adhering to the details of a particular one.

Nowadays flowcharts are still used for describing computer algorithms. [9] Modern techniques such as UML activity diagrams and Drakon-charts can be considered to be extensions of the flowchart.

Types

Sterneckert (2003) suggested that flowcharts can be modeled from the perspective of different user groups (such as managers, system analysts and clerks), and that there are four general types: [10]

Notice that every type of flowchart focuses on some kind of control, rather than on the particular flow itself. [10]

However, there are some different classifications. For example, Andrew Veronis (1978) named three basic types of flowcharts: the system flowchart, the general flowchart, and the detailed flowchart. [11] That same year Marilyn Bohl (1978) stated "in practice, two kinds of flowcharts are used in solution planning: system flowcharts and program flowcharts...". [12] More recently, Mark A. Fryman (2001) identified more differences: "Decision flowcharts, logic flowcharts, systems flowcharts, product flowcharts, and process flowcharts are just a few of the different types of flowcharts that are used in business and government". [13]

In addition, many diagram techniques are similar to flowcharts but carry a different name, such as UML activity diagrams.

Building blocks

Common symbols

The American National Standards Institute (ANSI) set standards for flowcharts and their symbols in the 1960s. [14] The International Organization for Standardization (ISO) adopted the ANSI symbols in 1970. [15] The current standard, ISO 5807, was revised in 1985. [16] Generally, flowcharts flow from top to bottom and left to right. [17]

ANSI/ISO ShapeNameDescription
Flowchart Line.svg Flowline (Arrowhead) [15] Shows the process's order of operation. A line coming from one symbol and pointing at another. [14] Arrowheads are added if the flow is not the standard top-to-bottom, left-to right. [15]
Flowchart Terminal.svg Terminal [14] Indicates the beginning and ending of a program or sub-process. Represented as a stadium, [14] oval or rounded (fillet) rectangle. They usually contain the word "Start" or "End", or another phrase signaling the start or end of a process, such as "submit inquiry" or "receive product".
Flowchart Process.svg Process [15] Represents a set of operations that changes value, form, or location of data. Represented as a rectangle. [15]
Flowchart Decision.svg Decision [15] Shows a conditional operation that determines which one of the two paths the program will take. [14] The operation is commonly a yes/no question or true/false test. Represented as a diamond (rhombus). [15]
Flowchart IO.svg Input/Output [15] Indicates the process of inputting and outputting data, [15] as in entering data or displaying results. Represented as a parallelogram. [14]
Flowchart Annotation.svg Annotation [14] (Comment) [15] Indicating additional information about a step in the program. Represented as an open rectangle with a dashed or solid line connecting it to the corresponding symbol in the flowchart. [15]
Flowchart Predefined Process.svg Predefined Process [14] Shows named process which is defined elsewhere. Represented as a rectangle with double-struck vertical edges. [14]
Flowchart Connector.svg On-page Connector [14] Pairs of labeled connectors replace long or confusing lines on a flowchart page. Represented by a small circle with a letter inside. [14] [18]
Off page connector.png Off-page Connector [14] A labeled connector for use when the target is on another page. Represented as a home plate-shaped pentagon. [14] [18]

Other symbols

The ANSI/ISO standards include symbols beyond the basic shapes. Some are: [17] [18]

ShapeNameDescription
Flowchart database.svg Data File or DatabaseData represented by a cylinder (disk drive).
Flowchart Document.svg DocumentSingle documents represented a rectangle with a wavy base.
Flowchart Document multiple.svg Multiple documents represented stacked rectangle with a wavy base.
Flowchar Manual input.svg Manual operationRepresented by a trapezoid with the longest parallel side at the top, to represent an operation or adjustment to process that can only be made manually.
Flowchart manual input.svg Manual inputRepresented by quadrilateral, with the top irregularly sloping up from left to right, like the side view of a keyboard.
Flowchart Preparation.svg Preparation or InitializationRepresented by an elongated hexagon, originally used for steps like setting a switch or initializing a routine.

Parallel processing

For parallel and concurrent processing the Parallel Mode horizontal lines [19] or a horizontal bar [20] indicate the start or end of a section of processes that can be done independently:

Software

Diagramming

Flowgorithm Flowgorithm Editor.png
Flowgorithm

Any drawing program can be used to create flowchart diagrams, but these will have no underlying data model to share data with databases or other programs such as project management systems or spreadsheet. Some tools such as yEd, Inkscape and Microsoft Visio offer special support for flowchart drawing. Many software packages exist that can create flowcharts automatically, either directly from a programming language source code, or from a flowchart description language.

There are several applications and visual programming languages [21] that use flowcharts to represent and execute programs. Generally these are used as teaching tools for beginner students. Examples include Flowgorithm, Raptor. LARP, Visual Logic, Fischertechnik ROBO Pro, and VisiRule.

See also

Related Research Articles

American National Standards Institute American non-profit organization that develops standards

The American National Standards Institute is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organization also coordinates U.S. standards with international standards so that American products can be used worldwide.

Dia (software) Diagramming software

Dia is free and open source general-purpose diagramming software, developed originally by Alexander Larsson. Dia uses a controlled single document interface (SDI) similar to GIMP and Inkscape.

Unified Modeling Language uchiha itachi

The Unified Modeling Language (UML) is a general-purpose, developmental, modeling language in the field of software engineering that is intended to provide a standard way to visualize the design of a system.

State diagram diagram used in computer engineering and computer science

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. Many forms of state diagrams exist, which differ slightly and have different semantics.

A modeling language is any artificial language that can be used to express information or knowledge or systems in a structure that is defined by a consistent set of rules. The rules are used for interpretation of the meaning of components in the structure.

Geometric dimensioning and tolerancing standardized code for engineers to specify parts for manufacturing

Geometric dimensioning and tolerancing (GD&T) is a system for defining and communicating engineering tolerances. It uses a symbolic language on engineering drawings and computer-generated three-dimensional solid models that explicitly describe nominal geometry and its allowable variation. It tells the manufacturing staff and machines what degree of accuracy and precision is needed on each controlled feature of the part. GD&T is used to define the nominal geometry of parts and assemblies, to define the allowable variation in form and possible size of individual features, and to define the allowable variation between features.

Computer-aided software engineering type of software tools

Computer-aided software engineering (CASE) is the domain of software tools used to design and implement applications. CASE tools are similar to and were partly inspired by computer-aided design (CAD) tools used for designing hardware products. CASE tools are used for developing high-quality, defect-free, and maintainable software. CASE software is often associated with methods for the development of information systems together with automated tools that can be used in the software development process.

A data-flow diagram (DFD) is a way of representing a flow of a data of a process or a 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 flow, there are no decision rules and no loops. Specific operations based on the data can be represented by a flowchart.

Flow diagram type of diagram representing a flow or set of dynamic relationships

Flow diagram is a collective term for a diagram representing a flow or set of dynamic relationships in a system. The term flow diagram is also used as a synonym for flowchart, and sometimes as a counterpart of the flowchart.

Ben Shneiderman American computer scientist

Ben Shneiderman is an American computer scientist, a Distinguished University Professor in the University of Maryland Department of Computer Science, which is part of the University of Maryland College of Computer, Mathematical, and Natural Sciences at the University of Maryland, College Park, and the founding director (1983-2000) of the University of Maryland Human-Computer Interaction Lab. He conducted fundamental research in the field of human–computer interaction, developing new ideas, methods, and tools such as the direct manipulation interface, and his eight rules of design.

Business Process Model and Notation

Business Process Model and Notation (BPMN) is a graphical representation for specifying business processes in a business process model.

Activity diagram diagram that models activity and process flows

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, 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.

Business process mapping refers to activities involved in defining what a business entity does, who is responsible, to what standard a business process should be completed, and how the success of a business process can be determined.

Systems Modeling Language general-purpose modeling language for systems engineering applications

The Systems Modeling Language (SysML) is a general-purpose modeling language for systems engineering applications. It supports the specification, analysis, design, verification and validation of a broad range of systems and systems-of-systems.

A process flow diagram (PFD) is a diagram commonly used in chemical and process 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. Another commonly used term for a PFD is a flowsheet.

Structured analysis method for analyzing and converting business requirements into specifications

In software engineering, structured analysis (SA) and structured design (SD) are methods for analyzing business requirements and developing specifications for converting practices into computer programs, hardware configurations, and related manual procedures.

DRAKON Algorithm mapping tool

DRAKON is an 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.

Function model

In systems engineering, software engineering, and computer science, a function model or functional model is a structured representation of the functions within the modeled system or subject area.

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.

Flow process chart

The flow process chart is a graphical and symbolic representation of the activities performed on the work piece during the operation in Industrial Engineering.

References

  1. SEVOCAB: Software Systems Engineering Vocabulary. Term: Flow chart. Retrieved 31 July 2008.
  2. Frank Bunker Gilbreth, Lillian Moller Gilbreth (1921) Process Charts . American Society of Mechanical Engineers.
  3. Graham, Jr., Ben S. (10 June 1996). "People come first". Keynote Address at Workflow Canada.
  4. American Society of Mechanical Engineers (1947) ASME standard; operation and flow process charts. New York, 1947. (online version)
  5. Hartree, Douglas (1949). Calculating Instruments and Machines. The University of Illinois Press. p. 112.
  6. Bashe, Charles (1986). IBM's Early Computers . The MIT Press. p.  327.
  7. Goldstine, Herman (1972). The Computer from Pascal to Von Neumann . Princeton University Press. pp.  266–267. ISBN   0-691-08104-2.
  8. Taub, Abraham (1963). John von Neumann Collected Works. 5. Macmillan. pp. 80–151.
  9. Bohl, Rynn: "Tools for Structured and Object-Oriented Design", Prentice Hall, 2007.
  10. 1 2 Alan B. Sterneckert (2003) Critical Incident Management. p. 126
  11. Andrew Veronis (1978) Microprocessors: Design and Applications. p. 111
  12. Marilyn Bohl (1978) A Guide for Programmers. p. 65.
  13. Mark A. Fryman (2001) Quality and Process Improvement. p. 169.
  14. 1 2 3 4 5 6 7 8 9 10 11 12 13 Gary B. Shelly; Misty E. Vermaat (2011). Discovering Computers, Complete: Your Interactive Guide to the Digital World. Cengage Learning. pp. 691–693. ISBN   1-111-53032-7.
  15. 1 2 3 4 5 6 7 8 9 10 11 Harley R. Myler (1998). "2.3 Flowcharts". Fundamentals of Engineering Programming with C and Fortran. Cambridge University Press. pp. 32–36. ISBN   978-0-521-62950-8.
  16. "ISO 5807:1985". International Organization for Standardization. February 1985. Retrieved 23 July 2017.
  17. 1 2 3 Flowcharting Techniques GC20-8152-1. IBM. March 1970. p. 10.
  18. 1 2 3 "What do the different flowchart shapes mean?". RFF Electronics. Retrieved 23 July 2017.
  19. Jonathan W. Valvano (2011). Embedded Microcomputer Systems: Real Time Interfacing. Cengage Learning. pp. 131–132. ISBN   1-111-42625-2.
  20. 1 2 Robbie T. Nakatsu (2009). Reasoning with Diagrams: Decision-Making and Problem-Solving with Diagrams. John Wiley & Sons. pp. 68–69. ISBN   978-0-470-40072-2.
  21. Myers, Brad A. "Visual programming, programming by example, and program visualization: a taxonomy." ACM SIGCHI Bulletin. Vol. 17. No. 4. ACM, 1986.

Further reading