1 / 19

STRUCTURE CHARTS

STRUCTURE CHARTS. Elements and Definitions. Software System Design. translates SRS into a ===> software system architecture: system’s static structure system’s possible dynamic behaviour data structures user interface design. Structured Analysis and Design. prepare and analyse a

derora
Download Presentation

STRUCTURE CHARTS

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. STRUCTURE CHARTS Elements and Definitions

  2. Software System Design • translates SRS into a ===> software system architecture: • system’s static structure • system’s possible dynamic behaviour • data structures • user interface design

  3. Structured Analysis and Design • prepare and analyse a Data Flow Diagram - DFD • derive from the DFD a Structure Chart

  4. Structure Chart • supports the system and module design phase • diagramming technique with annotations • hierarchy of modules • control (invocation) is explicitly modelled • data flows follow control hierarchy • decomposition is shown in the control hierarchy • software / computer oriented • derived from the DFD and further refined

  5. System Structure - Control Hierarchy S I1 I2 C1 O1 I11 I12 I21 C11 O11 O12

  6. Complete SC Design • Structure Chart Diagram • Data Dictionary (e.g. BNF) • Module Specifications (e.g. PDL) ===> consistent with DFD!

  7. Structure Charts - Module • process / subroutine / task • unit of execution • accepts parameters as inputs • produces parameters as outputs • parameters: data or control • can be invoked and can invoke • label: verb • linked to module specification label

  8. Structure Charts - Special Modules label • predefined (reused) module • highly useful • “macro” module • avoid label • multi-entry module • avoid label

  9. Structure Charts - Invocation / Call • call of subordinate module • connector element • NOT a data flow • one specific form of control flow • has a direction • no split or join • NO label

  10. Structure Charts - Invocation / Jump to Address • call jumps INTO invoked module • assembler type of programming • modification at run-time • avoid

  11. Structure Charts - Sequence of Execution • sequence of subordinate modules in the diagram is not reflecting a binding sequence of invocation • sequence of invocation is defined in the specification of the super-ordinate module • module specification is the decisive element X X1 X2 X3

  12. Structure Charts - Conditional Execution • call of subordinate module depends on a condition • no label • condition is defined in the module specification • module specification is the decisive element

  13. Structure Charts - Loops in the Execution • call of subordinate modules runs in a loop • no label or condition • loop (and its condition) is defined in the module specification • module specification is the decisive element

  14. Structure Charts - Data Flow • flow of information • data transfer • bound to invocation • has a direction • no splits or joins • label: noun • specified in data-dictionary label label label

  15. Structure Charts - Control Flow • flow of control (<> invocation) ==> control execution path of targeted module • bound to invocation • has a direction • no splits or joins • label: flag, decision, condition • specified in data-dictionary label label label

  16. Structure Charts - Data Store • storage for permanent data • database / file • passive; no activity beyond basic retrieval capacity • serviced by a module • label: noun • specified in data-dictionary and/or with an ER-diagram label

  17. Structure Charts - Devices / Interfaces • provides connection to peripheral devices • origin / destination of external data flows (controls) • not part of the software to be developed • label: noun • specified in data-dictionary label

  18. Structure Charts - SW Infrastructure • provides connection to external systems, databases, operating system, etc. • origin / destination of external data flows (controls) • not part of the software to be developed • label: noun • specified in data-dictionary label

  19. End of Section 3b coming up: an example for Structure Charts

More Related