1 / 14

Structured Design Tools

Structured Design Tools. Dr. Merle P. Martin CSU Sacramento. Agenda. Design approaches Structured approach Hierarchical Chart Data Flow Diagram. Design Approaches. Traditional (bottom-up) Structured (top-down) Radical Top-down Prototyping. Traditional Design Approach. Bottom-up

merry
Download Presentation

Structured Design Tools

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. Structured Design Tools Dr. Merle P. Martin CSU Sacramento

  2. Agenda • Design approaches • Structured approach • Hierarchical Chart • Data Flow Diagram

  3. Design Approaches • Traditional (bottom-up) • Structured (top-down) • Radical Top-down • Prototyping

  4. Traditional Design Approach • Bottom-up • Narrative, technical specs • User had to read them • Merely signed off • Resulting system • not expected by user • flaws

  5. Structured Design Approach • Top-down • First derived at general level • Successive refinement of detail • Primitive level (coding) • Computer Assisted System Engineering (CASE)

  6. Radical Top-down Approach • Used in this course • and in MIS 108, 119 • Partial system development • stubbing out of primitive level modules • prioritization of modules • top priority modules developed first • Lends itself to Prototyping

  7. Structured Approach Advantages • Reduces complexity (modularity) • Focuses on ideal (logical) system • Standardizes (team design) • Provides a future orientation • e.g.., future file • Relies less on artistry • engineering approach

  8. Structured Approach Sequence • Hierarchical Chart • Physical DFD current system (WHAT/HOW) • Logical DFD current system (WHAT only) • Logical DFD proposed system (revised WHAT) • Physical DFD proposed system (revised WHAT/HOW)

  9. Structured Approach Sequence Figure 6.1-1, pg.. 184)

  10. Hierarchical Chart • Terms: • parent,child,sibling • functional primitive • control module • How long should chart be?

  11. Hierarchical Chart - Colonial Heights Figure 6-6, pg.. 164

  12. Data Flow Diagram (DFD) • Purpose: communication with user • Components: • external entities (sources, sinks) • processes (subprograms) • data stores (files) • data flows (forms) • Symbols - Figure 6-7, pg.166

  13. Data Flow Diagram (DFD) • Figure 6-9, pg.169 - Hierarchical Chart • Figure 6-10, pg.170 - Context Level Diagram • Figure 6-11, pg.170 - First Level Explosion

  14. What You Should Remember • Different design approaches • Why Radical Top-down approach? • Structured Design sequence • Hierarchical Chart • DFD components and levels • Study Megavideo case (Case 6.1)

More Related