Message sequence chart: Difference between revisions

Revision as of 19:14, 8 January 2019

Latest revision as of 16:43, 10 July 2023

(9 intermediate revisions by 8 users not shown)

Line 1:

{{Short description|Interaction diagram from the SDL family}}

[[File:Typical MSC (Message Sequence Chart).png|thumb|The diagram shows three entities. At start the phone is disconnected. A user tries to establish a connection. A connection request is sent to the switch and a timer is started. An alternative deals with two possibles responses: 1 - The timer goes off because the switch did not reply and the phone goes back to the disconnected state.2 - The switch grants the connection and the call is established.]]

A '''message sequence chart''' (or '''MSC''') is an [[interaction diagram]] from the [[Specification and Description Language|SDL]] family standardized by the [[International Telecommunication Union]].

Line 6 ⟶ 7:

==History==

The first version of the MSC standard was released inon March 12, 1993.

The 1996 version added references, ordering and [[Inline expansion|inlining]] expressions concepts, and introduced HMSC<ref>{{cite web

Line 20 ⟶ 21:

|author = Øystein Haugen

|accessdate = 2009-09-19

|deadurlurl-status = yesdead

|archiveurl = https://web.archive.org/web/20110607104113/http://folk.uio.no/intime/msc2000.pdf

|archivedate = 2011-06-07

|df =

}}</ref> added object orientation, refined the use of data and time in diagrams, and added the concept of remote method calls.<ref>{{cite web

| url=http://www.sdl-forum.org/MSC2000present/sld007.htm

Line 53:

==Comparison to UML==

UML 2.0 [[Sequence diagram|Sequence Diagram]] is strongly inspired by the ITU-T MSC. Still, for historical reasons, the default basic principles are quite different:

* Lifelines

:* In an MSC, the vertical lines are autonomous execution entities. They usually represent state machines executing in parallel. The state machines need not be on the same computer.

Line 59:

* Arrows

:* In an MSC an arrow is usually an asynchronous message sent from one entity to another one. Once the message is sent the sending entity resumes its execution.

:* In a Sequence Diagram an arrow is usually understood as an operation call on a class. It is therefore synchronous and the calling entity hangs until the operation returns.{{fact|date=November 2022}}

It has been said that MSC has been considered as a candidate for the [[Unified Modeling Language#Interaction diagrams|interaction diagrams]] in UML.<ref>{{cite web

Line 84:

|title = Message Sequence Charts

|date = 2003-04-08

|author = [[David Harel]]

|accessdate = 2009-09-20

|deadurlurl-status = yesdead

|archiveurl = https://web.archive.org/web/20060826195305/http://www.comp.nus.edu.sg/~thiagu/public_papers/surveymsc.pdf

|archivedate = 2006-08-26

|author-link = David Harel

|df =

}}</ref><ref>{{cite journal

| url=http://www.springerlink.com/content/hfnna0r9jbl54ya4/

| title=LSCs: Breathing Life into Message Sequence Charts

| journal=Formal Methods in System Design

Line 97 ⟶ 96:

| pages=45–80

| date=2005-02-22

| author=[[David Harel]]

| accessdate=2009-09-20| doi=10.1023/A:1011227529550

| s2cid=1551133

|author-link = David Harel}}</ref><ref>{{cite journal

| url=http://portal.acm.org/citation.cfm?id=582429

| title=Multiple instances and symbolic variables in executable sequence charts

| journal=ACM SIGPLAN Notices

| volume=37

| issue=11

| pages=8383–100

| year=2002

| author=[[David Harel]]

| accessdate=2009-09-20| doi=10.1145/583854.582429

| citeseerx=10.1.1.20.5984

| author-link=David Harel

}}</ref>