出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/04/09 23:30:14」(JST)
mage:LampFlowchart.svg|thumb|right| A simple flowchart representing a process for dealing with a non-functioning lamp.]] A flowchart is a type of diagram that represents an algorithm or process, showing the steps as boxes of various kinds, and their order by connecting them with arrows. This diagrammatic [[Knowledge representation and reasoning|representationsolution to a given problem. Process operations are represented in these boxes, and arroram]]s; rather, they are implied by the sequencing of operations. Flowcharts are used in analyzing, designing, documenting or managing a process or program in various fields.[1]
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Flowcharts are used in designing and documenting complex processes or programs. Like other types of diagrams, they help visualize what is going on and thereby help the viewer to understand a process, and perhaps also find flaws, bottlenecks, and other less-obvious features within it. There are many different types of flowcharts, and each type has its own repertoire of boxes and notational conventions. The two most common types of boxes in a flowchart are:
A flowchart is described as "cross-functional" when the page is divided into different swimlanes describing the control of different organizational units. A symbol appearing in a particular "lane" is within the control of that organizational unit. This technique allows the author to locate the responsibility for performing an action or making a decision correctly, showing the responsibility of each organizational unit for different parts of a single process.
Flowcharts depict certain aspects of processes and they 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 are an alternative notation for process flow.
Common alternate names include: flowchart, 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 first structured method for documenting process flow, the "flow process chart", was introduced by Frank Gilbreth to members of the American Society of Mechanical Engineers (ASME) in 1921 in the presentation “Process Charts—First Steps in Finding the One Best Way”.[2] Gilbreth's tools quickly found their way into industrial engineering curricula. In the early 1930s, an industrial engineer, Allan H. Mogensen began training business people in the use of some of the tools of industrial engineering at his Work Simplification Conferences in Lake Placid, New York.
A 1944 graduate of Mogensen's class, Art Spinanger, took the tools back to Procter and Gamble where he developed their Deliberate Methods Change Program. Another 1944 graduate, Ben S. Graham, Director of Formcraft Engineering at Standard Register Industrial, adapted the flow process chart to information processing with his development of the multi-flow process chart to display multiple documents and their relationships.[3] In 1947, ASME adopted a symbol set derived from Gilbreth's original work as the ASME Standard for Process Charts.
Douglas Hartree explains that Herman Goldstine and John von Neumann developed a flowchart (originally, diagram) to plan computer programs.[4] His contemporary account is endorsed by IBM engineers[5] and by Goldstine's personal recollections.[6] The original programming flowcharts of Goldstine and von Neumann can be seen 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.[7]
Flowcharts used to be a popular means for describing computer algorithms and are still used for this purpose.[8] Modern techniques such as UML activity diagrams can be considered to be extensions of the flowchart. In the 1970s the popularity of flowcharts as an own method decreased when interactive computer terminals and third-generation programming languages became the common tools of the trade, since algorithms can be expressed much more concisely as source code in such a language, and also because designing algorithms using flowcharts was more likely to result in spaghetti code because of the need for gotos to describe arbitrary jumps in control flow. Often pseudo-code is used, which uses the common idioms of such languages without strictly adhering to the details of a particular one.
A flowchart for computing the factorial of N — written N! and equal to 1 × 2 × 3 × ... × N.
FlowChart Symbols List A typical flowchart from older basic computer science textbooks may have the following kinds of symbols:
It is important to remember to keep these connections logical in order. All processes should flow from top to bottom and left to right.
A number of symbols have been standardized for data flow diagrams to represent data flow, rather than control flow. These symbols may also be used in control flowcharts (e.g. to substitute for the parallelogram symbol).
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:[9]
Notice that every type of flowchart focuses on some kind of control, rather than on the particular flow itself.[9]
However there are several of these classifications. For example Andrew Veronis (1978) named three basic types of flowcharts: the system flowchart, the general flowchart, and the detailed flowchart.[10] That same year Marilyn Bohl (1978) stated "in practice, two kinds of flowcharts are used in solution planning: system flowcharts and program flowcharts...".[11] More recently Mark A. Fryman (2001) stated that there are 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".[12]
In addition, many diagram techniques exist that are similar to flowcharts but carry a different name, such as UML activity diagrams.
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 spreadsheets. Some tools offer special support for flowchart drawing. Many software packages exist that can create flowcharts automatically, either directly from source code, or from a flowchart description language. On-line Web-based versions of such programs are available.
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| リンク元 | 「フローチャート」「流れ図」 |
| 関連記事 | 「flow」「char」「chart」 |