1、BRITISH STANDARD BS 4058:1987 ISO 5807-1985 Specification for Data processing flow chart symbols, rules and conventions ISO title: Information processing Documentation symbols and conventions for data, program and system flowcharts, program network charts and system resources charts UDC 681.3 + 65.0
2、15.13:003.62BS4058:1987 This British Standard, having been prepared under the direction of the Information Systems Technology Standards Committee, was published underthe authority of the BoardofBSI and comes intoeffecton 29 May 1987 BSI 01-1999 First published April 1973 First revision May 1987 The
3、following BSI reference relateto the work on the standards: Committee reference IST/15 Draft for comment 85/64998 DC ISBN 0 580 15271 5 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Information Systems Technology Standards Committee (I
4、ST/-) to Technical Committee IST/15, upon which the following bodies were represented: Association of Computer Units in Colleges of Higher Education (ACUCHE) British Computer Society Ltd. British Telecommunications plc Business Equipment Trade Association Computing Services Association Department of
5、 Trade and Industry (National Physical Laboratory) Electricity Supply Industry in England and Wales Electronic Engineering Association HM Treasury (Central Computer and Telecommunications Agency) Institute of Data Processing Management Institute of Scientific and Technical Communicators Institution
6、of Electrical Engineers LAMSAC Ministry of Defence National Computing Centre Ltd. Amendments issued since publication Amd. No. Date of issue CommentsBS4058:1987 BSI 01-1999 i Contents Page Committees responsible Inside front cover National foreword ii 0 Introduction 1 1 Scope and field of applicatio
7、n 1 2 Reference 1 3 Definitions 1 4 Data flowchart 2 5 Program flowchart 2 6 System flowchart 2 7 Program network chart 2 8 System resources chart 2 9 Symbols 3 10 Conventions 11 11 Consolidated table of symbols 17 Annex A Example of data flowchart 21 Annex B Examples of program flowchart 22 Annex C
8、 Example of system flowchart 24 Annex D Example of program network chart 25 Annex E Example of system resources chart 25 National appendix A Additional symbols 26 Publications referred to Inside back coverBS4058:1987 ii BSI 01-1999 National foreword This British Standard has been prepared under the
9、direction of the Information Systems Technology Standards Committee. It is identical with ISO 5807-1985 “Information processing Documentation symbols and conventions for data, program and system flowcharts, program network charts and system resources charts”, published by the International Organizat
10、ion for Standardization (ISO), with the addition of national appendix A which has been included for information purposes only and does not form part of the standard. This standard supersedes BS 4058:1973, which is withdrawn. BS 4058 has been revised to maintain alignment with ISO 5807. This revision
11、 differs from the previous edition in that the terminology used to describe the symbols has been updated to reflect current practice. National appendix A gives symbols which were in the 1973 edition, but which are no longer included in this standard. Terminology and conventions. The text of the inte
12、rnational standard has been approved as suitable for publication as a British Standard without deviation. Some terminology and certain conventions are not identical with those used in British Standards; attention is drawn especially to the following. Wherever the words “International Standard” appea
13、r, referring to this standard, they should be read as “British Standard”. NOTECross-references are undated in the text. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with
14、 a British Standard does not of itself confer immunity from legal obligations. Cross-references International standard Corresponding British Standard ISO 2382/1-1974 BS 3527 Glossary of terms used in data processing Part 1:1976 Fundamental terms (Identical) Summary of pages This document comprises a
15、 front cover, an inside front cover, pages i and ii, pages 1 to 28, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on theinside front cover.BS4058:1987 BSI 01-1999 1 0
16、Introduction This International Standard consolidates the information given in ISO1028 and ISO2636, and in so doing, supersedes them. Charts are widely used to depict various types of information processing problems and their means of solution. This International Standard does not restrict their use
17、 to the particular applications exemplified herein. In-house rules may have to be devised to suit the process or data specification being considered. However, there are guiding principles which, if followed, will enhance readability and expedite cross-reference to the text. Charts consist of symbols
18、 having a given signification, brief explanatory text, and connecting lines. This International Standard does not deal with the wording of the text. Nevertheless, each symbol relates to an unambiguous and meaningful name (unabbreviated if possible) which is consistent throughout the documentation. C
19、harts may be used at various levels of detail; the number of levels depending on the size and complexity of the information processing problem. The level of detail should be such that the various parts and the interrelationship between the parts are comprehensible as a whole. Typically there will be
20、 a chart of the whole system showing the main constituent parts and this will form the top of a hierarchy of charts; each lower level providing a more detailed description of one or more parts shown on the next higher level chart. 1 Scope and field of application This International Standard specifie
21、s symbols to be used in information processing documentation and gives guidance on the conventions for their use in a) data flowcharts; b) program flowcharts; c) system flowcharts; d) program network charts; e) system resources charts. 2 Reference ISO 2382/1, Data processing Vocabulary Part 01: Fund
22、amental terms. 1) 3 Definitions For the purpose of this International Standard the definitions in ISO2382/1 and the following apply. 3.1 basic symbol symbol used when the precise nature or form of, for example, the process or data media is not known or when it is not necessary to depict the actual m
23、edium 3.2 specific symbol symbol used when the precise nature or form of, for example, the process or data media is known and when it is necessary to depict the actual medium 3.3 flowchart graphical representation of the definition, analysis, or method of solution of a problem in which symbols are u
24、sed to represent operations, data, flow, equipment, etc 1) At present at the stage of draft. (Revision of ISO 2382/1-1974.BS4058:1987 2 BSI 01-1999 4 Data flowchart Data flowcharts represent the path of data in the solving of a problem and define processing steps as well as the various data media us
25、ed. A data flowchart consists of a) data symbols to indicate the existence of data; they may also indicate the medium used for this data; b) process symbols to indicate the process to be executed on data; they may also indicate the machine function which is used for this process; c) line symbols to
26、indicate the data flow between processes and/or data media; d) special symbols to facilitate the reading and the writing of the flowchart. By definition, process symbols should be preceded and followed by data symbols. A data flowchart begins and ends with data symbols (except special symbols as spe
27、cified in 9.4). 5 Program flowchart Program flowcharts represent the sequence of operations in a program. A program flowchart consists of a) process symbols for the actual processing operations including symbols that define the path to be followed taking into account the logical conditions; b) line
28、symbols to indicate the flow of control; c) special symbols to facilitate the reading and the writing of the flowchart. 6 System flowchart System flowcharts represent the control of operations and the data flow of a system. A system flowchart consists of a) data symbols to indicate the existence of
29、data; they may also indicate the medium used for this data; b) process symbols to indicate the operations to be executed on data, as well as to define the logical path to be followed; c) line symbols to indicate data flow between processes and/or data media as well as the control flow between proces
30、ses; d) special symbols to facilitate the reading and writing of the flowchart. 7 Program network chart Program network charts represent the path of program activations and the interactions to related data. Each program in a program network chart is shown only once, whereas in a system flowchart it
31、may appear in more than one control flow. A program network chart consists of a) data symbols to indicate the existence of data; b) process symbols to indicate the operations to be executed on data; c) line symbols to show the flow between processes and data as well as the activations of processes;
32、d) special symbols to facilitate the reading and writing of the network charts. 8 System resources chart System resources charts represent the configuration of data units and process units suitable for the solving of a problem or of a set of problems. A system resources chart consists of a) data sym
33、bols to show input, output or storage devices; b) process symbols to represent processors, for example, central processing units, channels, etc.; c) line symbols to represent the data transfer between data devices and processors and control transfer between processors; d) special symbols to facilita
34、te the reading and the writing of the system resources chart.BS4058:1987 BSI 01-1999 3 9 Symbols 9.1 Data symbols 9.1.1 Basic data symbols 9.1.1.1 Data This symbol represents data, the medium being unspecified. 9.1.1.2 Stored data This symbol represents stored data in a form suitable for processing,
35、 the medium being unspecified. 9.1.2 Specific data symbols 9.1.2.1 Internal storage This symbol represents data, the medium being internal storage. 9.1.2.2 Sequential access storage This symbol represents data that is only sequentially accessible, the medium being, for example, magnetic tape, tape c
36、artridge, tape cassette. 9.1.2.3 Direct access storage This symbol represents data directly accessible, the medium being, for example, magnetic disk, drum, flexible disk.BS4058:1987 4 BSI 01-1999 9.1.2.4 Document This symbol represents human readable data, the medium being, for example, printed outp
37、ut, an OCR or MICR document, microfilm, tally roll, data entry forms. 9.1.2.5 Manual input This symbol represents data, the medium being of any type where the information is entered manually at the time of processing, for example, on-line keyboard, switch settings, push buttons, light pen, bar-code
38、wand. 9.1.2.6 Card This symbol represents data, the medium being cards, for example, punched cards, magnetic cards, mark sense cards, stub cards, mark scan cards. 9.1.2.7 Punched tape This symbol represents data, the medium being paper tape. 9.1.2.8 Display This symbol represents data, the medium be
39、ing of any type where the information is displayed for human use, for example, video screens, on-line indicators.BS4058:1987 BSI 01-1999 5 9.2 Process symbols 9.2.1 Basic process symbol Process This symbol represents any kind of processing function, for example, executing a defined operation or grou
40、p of operations resulting in a change in value, form or location of information, or in the determination of which one of several flow directions is to be followed. 9.2.2 Specific process symbols 9.2.2.1 Predefined process This symbol represents a named process consisting of one or more operations or
41、 program steps that are specified elsewhere, for example, a subroutine, a module. 9.2.2.2 Manual operation This symbol represents any process performed by a human being. 9.2.2.3 Preparation This symbol represents modification of an instruction or group of instructions in order to affect some subsequ
42、ent activity, for example, setting a switch, modifying an index register or initializing a routine.BS4058:1987 6 BSI 01-1999 9.2.2.4 Decision This symbol represents a decision or switching type function having a single entry but where there may be a number of alternative exits, one and only one of w
43、hich may be activated following the evaluation of conditions defined within the symbol. The appropriate results of the evaluation may be written adjacent to the lines representing the paths (see 10.3.1.2). 9.2.2.5 Parallel mode This symbol represents the synchronization of two or more parallel opera
44、tions. Example: NOTEProcesses C, D and E cannot commence until process A has been completed; similarly process F should await completion of B, C and D; but process C may start and/or end before process D has started and/or ended respectively.BS4058:1987 BSI 01-1999 7 9.2.2.6 Loop limit This symbol,
45、in two parts, represents the beginning and end of a loop. The two parts of the symbol have the same identifier. The conditions for initialization, increment, termination, etc., appear inside the symbol at the beginning or at the end according to the location of the test operation. Example: 9.3 Line
46、symbols 9.3.1 Basic line symbol Line This symbol represents the flow of data or control. Solid or open arrowheads shall be added to indicate direction of flow where necessary (see 10.2.1.2) or may be added to enhance the readability. 9.3.2 Specific line symbols 9.3.2.1 Control transfer This symbol r
47、epresents immediate transfer of control from one process to another, sometimes with a chance of the direct return to the activating process after the activated process completes its actions. The type of control transfer should be named inside the symbol, for example, call, fetch, event. 9.3.2.2 Comm
48、unication link This symbol represents data transfer by a telecommunication link.BS4058:1987 8 BSI 01-1999 9.3.2.3 Dashed line This symbol represents an alternative relationship between two or more symbols. The symbol is also used to surround an annotated area (see 9.4.3). Examples: a) in cases where
49、 one of a number of alternative outputs is used as an input to a process, or an output is used as an input for alternative processes, these symbols are connected by dashed lines.BS4058:1987 BSI 01-1999 9 b) an output which is used as an input in a succeeding process will be connected to the input by a dashed line. 9.4 Special symbols 9.4.1 Connector This symbol represents an exit to, or an entry from, another part of the same flowchart (see 10.2.2), and is used to break a line, and to continue it elsewhere. The corresponding connector symbols shall contain
