Various Exercises & Solutions

Note: For questions, please check your book in appropriate chapter and the back of the chapter exercise section.

Use Case Diagram

Ch6, Case Problem Suggestions, Pine Valley Furniture, Question 1

Solution:

Data Model (that is, Simple Class Diagram that has only class names specified)

Ch. 7, Case: Broadway Entertainment Company, Inc., Question 4

Solution:

The following UML diagram suggests cardinality and titles for relationships between the classes identified in BEC Figure 7-1.


Sequence Diagram

Try to read the following diagram with no addition information, and make sure you understand all the symbols and know their names:


Activity Diagram

Ch. 9, Problems and Exercises, Question 7

Solution:


Data Flow Diagram – correcting exercise

A system analyst developed the diagrams below while working on a Cap & Gown Ordering System. Are there any errors in the diagrams? If yes, please list them line by line in your examination booklet.

Solution:

Context diagram:

-  D1 inventory illegal – eliminate

-  Place Order illegal name of DF1 – should be Order

-  Shipp Cap & Gown illegal name EE2 – should be Shipping

- 

Level-0 diagram:

-  Shipp Cap & Gown data flow wrongly goes to Student – should go to Shipping

-  Receipt data flow wrongly goes to Shipping – should go to Student

-  Process 2 uses illegal name (noun) – should be Finalize Order

-  Process 1 is black hole (no output)

-  Process 2 creates outputs out of nothing (no input)

Critical Path

The table below depicts a system development project with the breakdown of tasks

code-named A through F. Fill in the blanks by specifying (a) expected tasks times, and (b) the critical path, (c) draw PERT diagram.

Task / Optimistic Time / Pessimistic Time / Realistic Time / Expected Time / Preceding Task
A / 4 / 8 / 6 / 6 / --
B / 7 / 11 / 9 / 9 / A
C / 3 / 7 / 5 / 5 / A
D / 9 / 13 / 11 / 11 / A
E / 6 / 10 / 8 / 8 / B
F / 3 / 9 / 6 / 6 / C,D,E

a) T expected = (T optimistic + T pessimistic + 4*T realistic)/6

b) Paths: ABEF = 6+9+8+6 = 29 – Critical Path

ACF = 6+5+6 = 17

ADF = 6+11+6 = 23

c) PERT diagram: