1 / 10

IS 460 Notes

IS 460 Notes. Documenting a System Analysis with Dataflow Diagrams By Thomas Hilton. System Analysis. The foundation skill of IS Professionals Understanding Whole Systems via the Systems View Outputs Information Other Inputs Data Other Processes Hardware Software People Procedures

marla
Download Presentation

IS 460 Notes

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. IS 460 Notes Documenting a System Analysis with Dataflow Diagrams By Thomas Hilton

  2. System Analysis • The foundation skill of IS Professionals • Understanding Whole Systems via the Systems View • Outputs • Information • Other • Inputs • Data • Other • Processes • Hardware • Software • People • Procedures • User Perspective!

  3. Systems are Complex • They Can Only be Understood by “Functional Decomposition” • Invoke the System-Supersystem-Subsystem view • Alternate between the Black Box Concept and the Closed System Concept • Create Successive Levels of Detail

  4. Information Systems Components • Entities External to the System • “Data” that Flows Through the System • Processes that Receive and Produce Data • “Data Stores” that store data

  5. Process name x.x Dx Data Store Name Information Systems Components Entity Name • External Entity . . . . . . . . . . • Dataflow . . . . . . . . . . . . . . • Process . . . . . . . . . . . . . . . • Datastore . . . . . . . . . . . . . Data Flow Name

  6. Levels of Detail • Context Level • Level 0 • Levels 1, 2, etc. • Functional Primitive Level

  7. x.x x.x x.x x.x x.x x.x x.x x.x x.x x.x x.x x.x x.x Processes Explode • Each process at a higher level corresponds to a set of processes at the next lower level Entity Name Entity Name

  8. Some Traits of the Example • Every dataflow starts somewhere and ends somewhere • Dataflows at a lower level agree with the dataflows of their parent process • No dataflow exits and enters the same process • Every process has at least one input and at least one output • Every process explodes to at least two subprocesses • Some processes don’t explode; these are called functional primitives, and they contain pseudocode

  9. Pseudocode, the Right Idea… • Pseudo = fake, false • Code = software instructions Select NAME, ADDRESS From TABLE Where CREDIT_LIMIT .GE. 10000 Fake variable names Fake table name Incorrect syntax Fake conditions

  10. Questions? On to an Example!

More Related