1、1 N T E R N AT IO N A L S TA N D A R D ISO/IEC 11411 First edition 1995-04-01 (Reaffirmed 2004) Information technology - Representation for human communication of state transition of software Technologies de lin formation - Representation pour un utilisateur final des 6tat.s de transition des iogici
2、els Nationaf Standard of Canada CAN/CSA-ISO/IEC-11411-96 International Standard ISO/IEC 11411: 1995 has been adopted, without modification, as CAN/CSA-ISO/IEC-ll411-96, which has been approved as a National Standard of Canada by the Standards Council of Canada. March 1996 Reference number lSO/l EC 1
3、 1 4 1 1 : 1 995 (E 60/IEC I1 41 1 : I995(E) Contents 0 lSO/IEC 1995 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing f
4、rom the publisher. ISOilEC Copyright Off ice Case postale 56 CH-1211 Geneve20 Switzerland ii 0 ISOAEC SO/IEC 11 41 1 : 1995(E) Foreword IS0 (the International Organization for Standardization) and IEC (the Inter- national Electrotechnical Commission) form the specialized system for worldwide standar
5、dization. National bodies that are members of SO or IEC participate in the development of International Standards through technical committees esta bIished by the respective organization to deal with particular fields of technical activity. IS0 and IEC technical com- mittees collaborate in fields of
6、 mutual interest. Other international organ- izations, governmental and non-governmental, in liaison with IS0 and I EC, also take part in the work. In the field of information technology, IS0 and IEC have established a join? technical committee, ISO/IEC JTC 1. Draft International Standards adopted b
7、y the joint technical committee are circulated to national bodies for vot- ing. Publication as an International Standard requires approval by at least 75 YO of the national bodies casting a vote. International Standard ISOAEC 11 41 1 was prepared by Joint Technical Committee ISO/IEC JTC 1, Informati
8、on technology, Subcommittee SC 7, Software engineering. Annexes A to D of this International Standard are for information only. . Ill ISOilEC 11 41 1 : 1995(E) Introduction Software in some fields can be represented by state transition diagrams and tables. The software changes its states through tra
9、nsitions. When a certain condition arises, the corresponding transition from state to state is performed. Conditions are brought about by input of data. The data may take various forms, e.9.: - signals, - commands, - messages: -tokens, flags, - characters, words, - records, etc. This International S
10、tandard describes minimum set of concepts and symbols for human communication of state transition of software. This International Standard a) defines the nature of state transitions of software; b) defines the notation of state transition elements; c) specifies a set of state transition elements. iV
11、 INTERNATIONAL STANDARD 0 lso/lEC ISO/IEC 11 41 1 : 1995(E) Information technology - Representation for human communication of state transition of software I Scope The underlying concept of this International Standard is that diagrams and symbols defined herein can be helpful in representing softwar
12、e functions and transitions and in improving human communication. The areas covered by this International Standard are development, communication and review of software requirement analysis and design. This International Standard is effective in the following fields of software. Interactive software
13、 -To describe the representation of functions and transitions on screens. Data communication software -To describe communication protocols and corresponding actions. -To describe the syntax. Lang uag eico m mand 2 Definitions For the purposes of this International Standard, the following definitions
14、 a p p I y . 2.1 state : A state is the unique value that represents the stage of progress of software in its execution. The state shall have a unique name as its identifier which is called state name. 2.2 transition : A transition is a change from one state to another state or the same state. A tra
15、nsition takes place when a condition is satisfied. An action may take place along with the transition. Formally, a transition consists of three parts: - direction part; - condition part; - action part. The direction part in turn consists of two state identifiers: - previous state identifier, pointin
16、g to the previous stale; - next state identifier, pointing to the next state. The condition part expresses the condition that must be satisfied for the action to take place and the change from one state to another. If mote transitions are defined to change from one state to another state or the same
17、 state, they shall be mutually exclusive, The action part represents the action which is performed by the software according to the condition. The action may be any processing or may be nil. 3 Specification 3.1 Specification of state States are a) Initial state Oneand only one state is initial. In t
18、he initial state, the software starts its activity. The initial state must be the previous state of at least one transition. b) Final state One or more states can be the final state. In final states the software terminates its activity. Each final state must be the next state of at least one transit
19、ion. c) lnitialifinal state The initial state can be the final state. In this case, the software terminates its activity and the activity may or may not be immediately restarted. The initial/final state must be the previous state of at least one transition and the next state of at least one transiti
20、on. d) Intermediate state A state that is not initial, not final, and not initial/final is called an intermediate state. It must be the next state of at east one transitjon from another state and the previous state of at least one transition to another state. lSO/IEC 11 41 1 : 1995(E) 0 ISOilEC 3.2
21、Specification of transition Transitions are a) Transition to another state This transition indicates the change from one state to another state. The previous state and the next state identifiers in the direction part of such a transition designate different states. b) Transition to the same state Th
22、is transition indicates the change from one state back IO the same state. The previous state and the next state identifiers in the direction part of such a transition designate the same state. a.3 Usage of state and transition Description of the state transition of software shall obey the following
23、conditions at the same time. 4 4. 4. a) One and only one initial state exists. b) Zero or more final state(s) exist(s). c) One or more transition(s) exist(s). d) A previous state and a next state in each transition exists. State diagram 1 Concept 1.1 Diagram In the state diagram, state and transitio
24、n are presented by symbols and texts. The state diagram represents permissible or defined changes of state. 4.1.2 Symbols 4.1.2.1 State A state is presented by a circle and text. A State b) Final state The charting notation of the final state IS as follows. n 0 name or (+. c) Initial/final state The
25、 initial state can be the final state at the same time. In this case, the charting notation of the state is as follows. 6 State or A State d) Intermediate state The charting notation of an intermediate state is as fo I lows. c State 4.1.2.2 Transition Transition Is presented by an arrow and text. Th
26、e text includes condition part and action part. There should be a clear delimiter between condition part and action part, e.g. slash or horizontal line. a) Transition to another state The charting notation for a transition from one state to another is as follows. a) Initial state The charting notati
27、on of the initial state is as follows. 2 ISO/IEC 1141 I : 1995(E) 0 ISO/IEC 5 State table b) Final state The charting notation of afinal state is as follows. 5.1 Concept 5.1.1 Diagram State transition may be also represented by a table. States and conditions will be represented in rows and columns.
28、Transitions are at the corresponding intersections. State No. I II In state table, a state has a state No. as an additional identifier of state. The state No. is a unjque number such as serial number of state. c) 1nitial:final state The initial state can be the final state at the same time. In this
29、case, the charting notation of the state is as follows. - 5.1.2 Symbols I Initial/ final I 5.1.2.1 State St at e a) Initial state The charting notation of an initial state is as follows. Initial Condition d) Intermediate state The charting notation of this state is as follows. I State name I,* -,I*
30、NOTE- In clause 5, the ellipsis (three dots) is used to show general solutions with an open number of repetition of symbols or a set of symbols as fotlows. 5.1 -2.2 Transition Transition is presented by an intersection. Action part and next slate number are described in the intersection. 4 0 ISOilEC
31、 lSO/IEC 11 41 1 : 1995(E) a) Transition to another state The charting notation for a transition from one state to another is as follows. a) Use of the state name as the next state identifier When it is easy to find astate in astate table using state name, state name may be used instead of state No.
32、 as the next state identifier in the intersection. In this case, the state No. part defined in 5.1 .2.1 can be omitted. State name b) Omission of an action part in a transition The action part in the transition may be left blank when there is no action executing with the transition or it is not nece
33、ssary to show the action. State No. I- 5.3 Usage and restrictions Condition . Action part state No. 5.3.1 Drawing Both hand-dram symbols and machine-drawn symbols are the same as those specified in 5.1.2. 5.3.2 Forms The state No. and the next state No. designate different states. Positions of state
34、 and condition are interchangeable, and this International Standard does not require a specific form sheet. b) Transition to the same state In case of transition to the same state, the next state No. is the same as the original state No. on d it i on m- . 5.2 Conventions Diagraming conventions : The
35、 following are examples of permitted variations of charting notations. . . 5 ISOAEC 11 41 1 : 1995(E) Annex A (i nf o rm ative) Example of a state diagram X 6 0 ISO/IEC INDEX lSO/IEC 11 41 1 : 1995(E) I1 Annex B (in formative) Example of a state table State Condition Invoke Read Index E TERM NX-PAG
36、E Add, Update Index Request Add, Update File Request Select Function 2 Teminate Display Index 3 Read this remains the continuing responsibility of the accredited standards-development organization. Those who have a need to apply standards are encouraged to use National Standards of Canada whenever p
37、racticable. These standards are subject to periodic review; therefore, users are cautioned to obtain the latest edition from the organization preparing the standard. The responsibility for approving National Standards of Canada rests with the Standards Council of Canada, 45 OConnor Street, Suite 1200, Ottawa, Ontario K1P 6N7.
