1. Prof. Awad Hanna ij Activity Event (a) Basic Activity Basic Logic Patterns for Arrow Diagrams

2. Prof. Awad Hanna 2 A (b) Independent Activities 410 B 12 3 A 6 B 9 (c) Dependent Activities Basic Logic Patterns for Arrow Diagrams (cont.)

3. Prof. Awad Hanna 2 A (d) A Merge 4 6 B 8 (e) A Burst C Activity C depends upon the completion of both Activities A & B 8 A 6 2 B 4 C Activities B and C both depend upon the completion of Activity A Basic Logic Patterns for Arrow Diagrams (cont.)

4. Prof. Awad Hanna (f) A Cross 20 18 C 16 D 14 A 12 B Activities C and D both depend upon the completion of Activities A and B Basic Logic Patterns for Arrow Diagrams (cont.)

5. Prof. Awad Hanna 10 8 C 6 D 4 A 2 B 8 C 6 4 A 2 Divide node to correct (a) Incorrect Representation (b) Correct Representation D 5 B Dummy The use of dummy to maintain unique numbering of activities

6. Prof. Awad Hanna 410 4 11 A B A B Divide node to correct Dummy (a) Incorrect Representation (b) Correct Representation The use of dummy to maintain unique numbering of activities (cont.)

7. Prof. Awad Hanna Removal of Redundant Dummies A A A A B B B B CC Original DiagramDiagram after removal of redundant dummies (a) (b)

8. Prof. Awad Hanna Removal of Redundant Dummies (cont.) A A A A C C B C BB Original DiagramDiagram after removal of redundant dummies (c) (d) BE C E EE

9. Prof. Awad Hanna Combining Beginning and Ending Nodes AC E BF

10. Prof. Awad Hanna Combining Beginning and Ending Nodes (cont.) 2812 AE 414 61016 CF B 2 10 8 16 (a) Incorrect Representation (b) Correct Representation

11. Prof. Awad Hanna Basic Rules of Network Logic Rule 1. Before an activity may begin, all activities preceding it must be completed. (Activities with no predecessors are self-actuating when the project begins.) Rule 2. Arrows imply logical precedence only. Neither the length of the arrow nor its “x” direction on the drawing have any significance. (An exception to this rule is discussed under “Time-scaled Networks”.)

12. Prof. Awad Hanna Basic Rules of Network Logic (cont.) Rule 3. Event numbers must not be duplicated in a network. Rule 4. Any two events may be directly connected by more than one activity. Rule 5. Networks may have only one initial event (with no predecessor) and only one terminal event (with no successor). Rule 6.  Even, odd, in fives or tens  Smaller numbers to the left  Each activity has its unique number

13. Prof. Awad Hanna Retailing wall arrow diagram - start event approach Footing 1 Wall 1 Footing 1 Wall 1 Wall 2 28 Footing 1 4 Wall 1 10 Wall 2 6 Wall 1 Wall 2 Footing 1 Footing 2 (b) (c) (d) (a)

14. Prof. Awad Hanna Activity List with Redundant Removed - Remodeling Chemical Laboratory

15. Prof. Awad Hanna Arrow Diagram - Remodeling Chemical Laboratory