week 2 - DFD_techniques_Ch3-supple

week 2 - DFD_techniques_Ch3-supple - ACC 7145 System...

Info iconThis preview shows pages 1–12. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: ACC 7145 System Documentation Techniques Dr. Myles Stern Department of Accounting Data-Flow Diagrams C Process 1 .0 T ake O rd er Page 4 Data-Flow Diagrams C External (to the system being modeled) entity C The text calls these data sources and data destinations. C What about the "credit manager" in figure 3-3 (customer payment process)? C u s to m e r Page 5 Data-Flow Diagrams C Data flow C Can represent physical as well as data flow Page 8 Data-Flow Diagrams C Data store C Can use it for physical items as well as data P ro d u c ts P ro d u c ts Page 7 Figure 3-3 Page 6 Order-Taking Ite m s R e q u e s te d C u s to m e r C u s to m e r d e t a ils C u s to m e r I n f o O rd er h ead er in f o O p en O rd ers 2 .0 C hec k I te m s I t e m s f ille d L in e - I t e m s 1 .0 T ake O rd er O r d e r in f o Q u a n t it ie s o n h a n d P ro d u c ts Page 3 Data Flow Diagrams Problems with processes r Black hole: inputs but no outputs Ite m s R e q u e s te d C u s to m e r 1 .0 T ake O rd er C u s to m e r d e t a ils C u s to m e r I n f o O rd er h ead er in f o O p en O rd ers 2 .0 C heck Ite m s O r d e r in f o Q u a n t it ie s o n h a n d P ro d u c ts Page 9 Data Flow Diagrams Problems with processes r Miracle: outputs but no inputs 1 .0 T ake O rd er O rd er h ead er in f o O p en O rd ers 2 .0 C hec k Ite m s I t e m s f i ll e d L in e - I t e m s O r d e r in f o Q u a n t it ie s o n h a n d P r o d u c ts Page 10 Data Flow Diagrams Problems with processes r Gray hole: inputs are not sufficient to produce the outputs Ite m s R e q u e s te d C u s to m e r 1 .0 T ake O rd er C u s to m e r d e t a i ls C u s to m e r In fo O rd er h ead er in f o O p en O rd ers 2 .0 C heck I te m s I t e m s f il l e d L in e - I t e m s O r d e r in f o Page 11 DFDs in Practice C Symbol sets: Yourdan versus Gane & Sarson Page 12 DFDs in Practice C How to portray detail C Context diagram: model with a single process C Level 0 diagram: all major processes are shown. 1.0, 2.0, etc. C Level 1 diagram: subdivide each major process as needed. 1.1, 1.2, 1.3, etc. C Keep going until each process shown is "simple." Page 13 ...
View Full Document

Page1 / 12

week 2 - DFD_techniques_Ch3-supple - ACC 7145 System...

This preview shows document pages 1 - 12. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online