1. Informatics 121 Software Design I
Lecture 11
Duplication of course material for any commercial purpose without the explicit written permission of the professor is prohibited.

2. Discussion

3. Today’s lecture
Design notations

4. Design designer plan maker change in the world other stakeholders
audience
experiences

5. A design artifact
An externalized representation used to further a design project
design problem, design solution, or both
partial or complete
fluid or frozen

6. Example

7. Example

8. Example

9. Example

10. Example

11. Purpose of design artifacts
Design artifacts to think
Design artifacts to talk
Design artifacts to prescribe

12. Thinking design artifact

13. Thinking design artifact

14. Thinking design artifact

15. Talking design artifact

16. Talking design artifact

17. Talking design artifact

18. Prescribing design artifact

19. Prescribing design artifact

20. Prescribing design artifact

21. Abstraction
An abstraction is formed by reducing the information content of a concept or an observable phenomenon, typically to retain only information which is relevant for a particular purpose
choice of what to include
choice of what not to include
Each abstraction makes some information readily available at the expense of obscuring or removing other information

22. Floor plan

23. Verilog

24. Page layout

25. Mechanical engineering diagram

26. Schematic

27. Product sketch

28. Model

29. Design notation
A design notation offers a language for specifying certain aspects of a design artifact
textual and/or graphical vocabulary for specifying individual and composite elements
rules governing how individual elements can be combined into composite elements
implicit and/or explicit semantics for giving meaning
Each design notation is typically suited for a particular domain and a particular purpose
Every design notation invariably introduces abstraction

30. Example notation

31. Example notation

32. Example notation

33. Considerations in choosing a design notation
Who is the audience?
What is the objective?
What is the timeframe?

34. Expressiveness versus usability
high
low
expressiveness
usability

35. Software design
Design artifacts
Design notation

36. Software design artifact

37. Software design artifact

38. Software design artifact

39. Thinking software design artifact

40. Talking software design artifact

41. Prescribing software design artifact

42. Class diagram

43. User interface mock-up
[balsamiq]

44. Entity relationship diagram

45. Sequence diagram

46. Example notation

47. Example notation

48. Example notation

49. Unified Modeling Language
Structure diagram
class diagram
component diagram
package diagram
deployment diagram …
Behavior diagram
activity diagram
use case diagram
sequence diagram
communication diagram

50. Class diagram

51. Sequence diagram