1 / 20

MSC

MSC. Structuring MSCs Using Message Sequence Charts for real systems. Features. Inline expressions – for alternatives, loops, exceptions and options MSC references – such that MSCs may be referenced within other MSCs

aria
Download Presentation

MSC

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. MSC Structuring MSCs Using Message Sequence Charts for real systems

  2. Features • Inline expressions – for alternatives, loops, exceptions and options • MSC references – such that MSCs may be referenced within other MSCs • MSC expressions – combining MSCs to express alternatives, parallel merge and loops • Gates – flexible connection points between references/expressions and their surroundings • HMSC – High level MSC for better better overview of MSC documents • Substitution– generalizing MSCs wrt. message, instance and MSC names • General ordering – when neither strict order nor no order is the situation • MSC Document – declaring a collection of MSC and their data

  3. diagram frame heading instance condition output event input event message message to environment instance end Simple MSC in a nutshell mscUser_accepted AC System User Idle Code OK Unlock Card out Door unlocked

  4. Idle User_Accepted Door open msc reference actual gate MSC references msc Auto_Door AutomaticDoor User AC System Unlock Opened

  5. MSCs in MSC document

  6. hmsc start connection point msc reference Idle loop User_accepted Unlocked_reset User_rejected restrictive condition Door unlocked Unlocked_timeout Unlocked_unclosed alternative High level MSC - HMSC msc AC_System_Overview

  7. msc AC_System_Overview Idle User_rejected User_accepted Door unlocked Unlocked_reset Unlocked_timeout Unlocked_unclosed Restrictive conditions • only for HMSC conditions • only for global (initial and final) conditions • conditions may have a set of names

  8. Idle User_accepted Unlocked_unclosed alt Unlocked_resetalt Unlocked_timeout User_rejected reference expression Door unlocked Reference expression msc AC_System_Overview

  9. Gate application explicitly named gates implicitly named gate

  10. Gate definition

  11. expression frame Door unlocked operator operand separator alternative either this or this Idle Inline expressions msc Unlocked_Idle User AC System door alt door Lock Push door Opened door gates propagate alt Closed door Lock door Alarm Error

  12. Door unlocked exception either this orcontinue themain road option either this ornothing Idle Exception and Option msc Unlocked_Idle User AC System door exc door Lock Push door Opened door exc door Alarm Error opt Pull door Closed door Lock

  13. infinite loop User_accepted Unlocked_Idle User_rejected Idle Idle Loop msc AC_System_Overview User AC System loop<inf> alt

  14. User_accepted subst Userby User1 User_accepted subst Userby User2 Parallel merge Two parallel behaviours msc TwoUsersAccepted

  15. General order symbol Coregion General order in one instance msc User_accepted AC System User decomposed Idle Code Card out OK Unlock Door unlocked

  16. Incomplete messages Lost message

  17. Idle Idle Door open Door unlocked Auto_Door subst User_Acceptedby Simple_Accepted User_Accepted Substitution msc Auto_Door msc SimpleDoor AutomaticDoor User AC System Unlock Opened msc Simple_Accepted User AC System PushButton Unlock

  18. Summary ways to achieve overview: • HMSC for over viewing large specifications • Inline expressions for over viewing small variations ways to combine MSCs: • MSC references • MSC gates • MSC reference expressions improved generalization mechanisms: • Substitution of MSCs, message names, and instance names

  19. Remaining issues MSC 2000 issues: • Document diagrams • Data • Imperative conditions (when) • Better decomposition rules UML 2.0: • Essentially the same • Slightly different syntax

  20. properties 1 objects 1 3 3 context ••• 2 content ••• ••• ••• MSC is used to: 4,5 • Precisely define behaviour properties such as: • use cases • interface behavior cases, protocol sequences • service behaviors • Partially synthesise designs • Verify that designs satisfy specified behaviour properties • Describe test cases • Document simulation traces • Generally improve understanding and communication about interaction problems

More Related