cisc 323 introduction to software...

CISC 323Introduction to Software Engineering

Week 3

OOP, UML, Software Process

Lectu re 1 : Software Process

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Software Process

• T o m an ag e com p l ex i ty of software, req u i re a process th at cod i fi es th e acti v i ti es of software d esi g n , d ev el op m en t an d v al i d ati on

• T h ere are m an y p rocesses. W h i ch on e i s correct d ep en d s on th e d esi red q u al i ty attri b u tes of th e sy stem u n d er con stru cti on .

• Process m od el : d escri b es p rocess

• R ea d i n g : B ah ram i C h ap ter 3

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Examples of Software Processes

• W aterfal l p rocess

• I n crem en tal p rocess

– Microsoft

• …T h e r e a r e m a n y m o r e !

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Ad Hoc Process

• a n a l y s i s - - - > c o d e - - > t e s t - - > c o d e - - > t e s t …

• m a y w o r k f o r s m a l l p r o g r a m , o n e p r o g r a m m e r

• f o r l a r g e r s y s t e m s , d o o m e d t o f a i l u r e

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Waterfall Model

SystemRequirements

SoftwareRequirements

Product Design

ProgramDesign

Coding

Testing

Operations

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Waterfall Model

SystemRequirements


Product Design

ProgramDesign

Coding

Testing

Operations

•Description of complete system.

•Boundaries between hardware and software components.

•Example: brakes in a car

•braking system includes •foot pedal•brake pads•software to control brakes.

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Waterfall Model

SystemRequirements


Product Design

ProgramDesign

Coding

Testing

Operations

Includes: functional requirementsE.g., depressing the brake slows the car down

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Waterfall Model

SystemRequirements


Product Design

ProgramDesign

Coding

Testing

Operations

Includes: non-functional requirements• E.g. performance: brakes must respond within 100 ms of being activated• E.g., availability: if software fails, brakes must still function manually.

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Waterfall Model

SystemRequirements


Product Design

ProgramDesign

Coding

Testing

Operations

• Description of functions the software must fulfill and associated quality attributes.

• Expressed from point of view of a user of the system.

• Does not include implementation decisions such as algorithms, data structures used to address these requirements.

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Waterfall Model

SystemRequirements


Product Design

ProgramDesign

Coding

Testing

Operations

Example: for course marks program, functions are:

• Student can access system from any CASLab machine• Student can specify course in which he/she is enrolled and request grades for that course• Grades recorded for that course will be presented to user in a readable format• …etc.

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Waterfall Model

SystemRequirements


External Design

InternalDesign

Coding

Testing

Operations

• Describes software design meeting the requirements specified above. • Design is external, from point of view of a user of the software. • Shows how requirements are mapped to system features.

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Waterfall Model

SystemRequirements


External Design

InternalDesign

Coding

Testing

Operations

• May include:• detailed functional design• screen mockups• interaction design.

• Does not describe system implementation, e.g., algorithms, data structures, etc.

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Waterfall Model

SystemRequirements


External Design

InternalDesign

Coding

Testing

Operations

Describes implementation of software. Includes, e.g.,

• Deployment architecture• Component architecture• Component interfaces• Data model• Protocols (how components communicate with each other.)

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Waterfall Model

SystemRequirements


External Design

InternalDesign

Coding

Testing

Operations

Actual programming of software.

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Waterfall Model

SystemRequirements


External Design

InternalDesign

Coding

Testing

Operations

Ensuring software performs to specification. Addresses both function and quality attributes.

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Waterfall Model

SystemRequirements


External Design

InternalDesign

Coding

Testing

Operations

Once software has been delivered, revisions will be required to address

• errors• new requirements

This is called software maintenance

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Waterfall Model

SystemRequirements


Product Design

ProgramDesign

Coding

Testing

Operations

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Bahrami's Simplification

What

How

Do It

Test

Use

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Premise of Waterfall Model

• E a c h s t e p c o m p l e t e d s u c c e s s f u l l y p r o v i d e s s t r o n g f o u n d a t i o n f o r n e x t s t e p

• F o r c e s d e v e l o p e r s t o c o p e w i t h d a t a a n d c o n t r o l f l o w s , e r r o r s , p r o b l e m s e a r l i e r i n d e v e l o p m e n t

• E a c h s t e p s h o u l d b e p e r f o r m e d b y t h o s e s k i l l e d i n t h o s e s t e p s

• D o c u m e n t e v e r y t h i n g : s o f t w a r e r e q u i r e m e n t s , p r e l i m i n a r y d e s i g n , i n t e r f a c e d e s i g n , f i n a l d e s i g n , t e s t p l a n / t e s t r e s u l t s , o p e r a t i n g i n s t r u c t i o n s

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Relative Cost to Fix or Change Software Throughout Lifecycle

0

20

40

60

80

100

120

140

160

Req Code AcceptTest

Large ProjectSmall Project

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Waterfall Model

• E m p h a s i s o n c a t c h i n g p r o b l e m s e a r l y t h r o u g h r e q u i r e m e n t s , d e s i g n s t a g e s

� � � � �� " � � � � �

� � � � � � � � � � � ��

• C l e a r d o c u m e n t a t i o n c r e a t e d i n e a c h p h a s e

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� � � � � " � � �� • W o r k s b e s t f o r w e l l -u n d e r s t o o d s t y l e s o f s o f t w a r e

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� �� " � � � � � � � � �" � �� "

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Strengths and Weaknesses of Waterfall Model (1)

• P r i m a r y f u n c t i o n

– d e t e r m i n e o r d e r o f s t a g e s i n s o f t w a r e d e v e l o p m e n t

– s e t t r a n s i t i o n r e q u i r e m e n t s f r o m o n e s t a g e t o a n o t h e r

• W a t e r f a l l M o d e l

– d o c u m e n t ( o r t a s k ) d r i v e n

– b e t t e r t h a n a d -h o c p r o c e s s

– m o s t w i d e l y u s e d p r o c e s s m o d e l i n s t a n d a r d s a n d i n d u s t r y

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• w e a k n e s s e s

– e m p h a s i s o n f u l l y e l a b o r a t e d d o c u m e n t s b e f o r e g o i n g o n t o n e x t s t a g e

– o n l y w o r k s f o r w e l l d e f i n e d , m a t u r e , p r e d i c t a b l e t y p e s o f s o f t w a r e

– d o e s n ’ t w o r k f o r h i g h l y i n t e r a c t i v e s o f t w a r e , n e w t e c h n o l o g y , r e s e a r c h

– r e a l p r o j e c t s r a r e l y f o l l o w s e q u e n t i a l f l o w o f m o d e l

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• w e a k n e s s e s

– d i f f i c u l t f o r c u s t o m e r t o s t a t e a l l r e q u i r e m e n t s e x p l i c i t l y a t s t a r t o f p r o j e c t

– w o r k i n g v e r s i o n o f p r o g r a m n o t a v a i l a b l e u n t i l v e r y l a t e i n p r o j e c t l i f e -s p a n

– m a j o r b l u n d e r m a y n o t b e d i s c o v e r e d u n t i l v e r y l a t e

– s e q u e n t i a l s t y l e l e a d s t o b o t t l e n e c k s a n d d o e s n ’ t l e n d i t s e l f t o p a r a l l e l a c t i v i t i e s

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Software Prototyping

t r a d i t i o n a l u n d e r s t a n d i n g o f “ p r o t o t y p e ” :

m o c k -u p o f a n e w l y e n g i n e e r e d p r o d u c t

– p r o t o t y p e a i r c r a f t t o t e s t f l y i n g , c h e c k s y s t e m s

– m a k e r e f i n e m e n t s b e f o r e g o i n g i n t o p r o d u c t i o n

– h a v e t o b u i l d n e a r l y w h o l e t h i n g ( a i r f r a m e , e n g i n e s , c o c k p i t c o n t r o l s , h y d r a u l i c s , l a n d i n g g e a r , e l e c t r o n i c s , e t c . ) b e f o r e t e s t

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Software Prototyping

• f o r s o f t w a r e , p r o t o t y p e u s e d t o

– t r y o u t o n c u s t o m e r s

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� � � �� – t r y o u t p o s s i b l e t r o u b l e a r e a s

� � � � � � � �� ! � � � � � � � � � ��

� � � � � �" � # � �! � � � �� $

� � " � � � � $ � � � $ � � � � � � � � � � � � � �

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Key considerations for using Prototypes

• o b j e c t i v e s f o r e a c h p r o t o t y p e a c t i v i t y s h o u l d b e c l e a r l y e s t a b l i s h e d

• d e f i n e t h e p r o t o t y p e p r o c e s s a h e a d ( p r o t o t y p i n g d o e s N O T m e a n h a c k i n g )

• r e s u l t s f r o m p r o t o t y p i n g e f f o r t m u s t b e d o c u m e n t e d a n d a n a l y z e d b e f o r e d e c i s i o n o n h o w t o p r o c e e d

• c o m p l e t e o n e p r o t o t y p e a n d a n a l y z e r e s u l t s b e f o r e s t a r t i n g n e x t i t e r a t i o n

• p r o t o t y p e r e s u l t s c a n b e

� � � � � �! � ��

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� � � �� $ � � � � � � � ��

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Competing Philosophies on Prototyping (1)

• t h r o w a w a y p r o t o t y p e

� � � � � � � � � � � � � � � � � � � � � � � � � � � � �

� � � � � � � � � � � � � � � � � � � � � � � � � � �� # � � � � � � � � ��

• q u i c k & d i r t y p r o t o t y p e

� � � � � � � � �� # � � $ � � � � � � ��

$ �� " � �

� � � � � � � � $ � � � � ��

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� � �� ! " ! �# $ ��% �!'&

� ( � � $ � � ) "& � � ( � � � *+ � � � % �� + � % + �� ,

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Competing Philosophies on Prototyping (2)

• d e t a i l e d d e s i g n -d r i v e n p r o t o t y p e

� *� � ( �� "! � � ) $% + � �� ( � ) � !

� ( � ) � ! % � ( ! � + � � ) � �� * �% + � � � � � " ! �

� � �# �%$ &"' (*) +, -". / 0 +' 1 23 / 4 & / , 23 ) +' 56 7 3 ' 2 86 , 9 + 0

• n o n -f u n c t i o n i n g m o c k -u p s

: ;< = >@? ACB DFE <G HJI K LI KE M@N ? OQP R

: P N P < SSCT RG KU D H ? N U DN P < S ? V< W R S ? N K L D = RP ON < = H KP O RP ON LG K W

N T N O? W RG K ;? N N ? N

: P N ? H O K L K S S KB L S KB K L O< N XN

: N K W ? O D W ? N K = R < R? G K = SCT KG K = ; K W RP O? G N ;G ? ? =N K = SCT

: ? V< W R S ? N W < =P < S ST RG ? R <G ? H >T H ? U ? S K R? G N

Y , 3 &6 Z6 6 2 Z /6 4 4 . ( , [ / Z Z3 23 5 [ / Z +'

Y , 3 Z ' + 0 / 4 Z 0 3 ' ( +, Z + &

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Weaknesses of Prototyping

• w h a t d o w e d o w i t h p r o t o t y p e w h e n i t h a s s e r v e d i t s p u r p o s e ?

• customers see what appears to be a working system

� ! " ##%$ &(' #) *,+ -' * &(' . / 0 * &1 2 &(' / 043 - - 5 " 3 ) 6 " # 0 3 - / 0 .' 7

� 2 ! *,+ 5' . ! ' 8 9' 2 * ! 9 . + *,+ *$ 9' *,+ 6' ) ' # 0;: ' .' ) !$ ! *' 5

� 5 " 3 " -' 5' 3 * 5 "$ 2 + # # " 9 !' *,+ 2 ! * + 5' . ! ) ' 5 " 3 ) !

• d ev el oper has mad e impl ementation compromises

� 043 " 9 9 .+ 9 . 0 " *' < => + . 9 .+ - . " 5 5 043 - # " 3 - " -'

� 5 "$ 6' 2 + 5' " 3 043 *' - . " # 9 " . * + ? * &(' !$ ! *' 5

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The Incremental Model

• combination of waterf al l mod el and prototyping

• each seq uence of the process

� 9 .+ ) 2' ! " ) ' # 0;: ' . " 6#(' 1 043 2 .' 5' 3 * 7 + ? * &(' ! + ? * / " .'

� 2 " 3 043 2 + . 9 + . " *' * &(' 9 .+ *,+ *$ 9 043 - 9 " . ") 0 - 5• f irst increment is of ten the core prod uct

� 6 " ! 0 2 .' 0 .' 5' 3 * ! 5' *

� ! 9 9 #(' 5' 3 * " .$ ?' " * .' ! 3 ) ' # 0;: ' .' )• ev al uation with user

• pl an f or nex t increment

• repeat until f ul l prod uct d el iv ered

• f ocus on d el iv ery of operational prod uct with each increment

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Evolutionary Rapid Prototyping

• “ an easil y buil t, read il y mod if iabl e, ul timatel y ex tensibl e, partial l y specif ied , working mod el of primary aspects of a proposed system”

• primary obj ectiv e: “ prov id e a cost-ef f ectiv e means of d iscov ering the true and compl ete set of system f unctional req uirements that wil l optimal l y satisf y the l egitimate business need s of the user”

• not throw-away: ev ol v es into f inal system

• not q uick-and -d irty: d etail ed anal ysis and d esign take pl ace

• not mock-up: uses real user d ata

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Steps in Evolutionary Rapid Prototyping (1)

• * * * P rototype most important aspects of the system f irst* * *

• * * * H av e a prototyping process/ proced ure d ef ined ahead * * *

• d iv id e appl ication into wel l d ef ined pieces

� 9 0' 2' ! * & " * 2 " 3 6' ) ' : ' # + 9' ) 043 ) ' 9' 3 ) ' 3 * #$

• d ecid e ord er of prototyping d if f erent pieces

� + .) ' . 043 - 5 "$ 2 & " 3 -' " ! ) ' : ' # + 9 5' 3 * 9 .+ 2' ' ) !

• pl an prototyping activ ities

�

) ' 2 0) ' + 6� ' 2 * 0 : ' !

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) + 3 � * -' * 043 *,+ ' 3 )#(' ! ! # + + 9 + ? 9 .+ * + *$ 9 043 -

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Steps in Evolutionary Rapid Prototyping (2)

• get prototype working

• ev al uate your resul ts

� ! & + / 0 * * + ! + 5' + 3 ' �

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�' ' 9 + 6� ' 2 * 0 : ' ! 043 5 0 3 ) * &(' / & + #(' * 0 5'

• make ref inements

• upd ate req uirements d ocumentation

• f reez e portion of prototype that’ s d one

• mov e on to nex t piece to prototype

• buil d f inal prod uct f rom prototype pieces

�

? 043 " # 9 . + ) 2 * 5 "$ 3 ' ' ) ! + 5' ? 043 ' * 3 043 - *,+ ! " * 0 ! ?$ 9 . + ) 2 *

.' 0 .' 5' 3 * !

�

? 043 " # 9 . + ) 2 * 5 ! * 6' : " # 0) " *' ) " - " 043 ! * 9 .+ � ' 2 * .' 0 .' 5' 3 * !

6' ?+ .' * .3 043 - + : ' . *,+ !' .

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Evolutionary Rapid Prototyping

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Weakness of Evolutionary Rapid Prototyping

• can easil y turn into “ q uick and d irty”

• non-f unctional issues such as perf ormance l ef t until l ast

� 3 + + : ' . " # # ) ' ! 0 - 3 ) + 3 ' *,+ " ) ) .' ! ! * &(' !'• some appl ications d o not l end themsel v es to rapid

prototyping

� + 9' . " * 043 - !$ ! *' 5 !��

*' #(' 2 + 5 5 ! + ? * / " .'�

.' " # * 0 5' !$ ! *' 5 !��

) 6 5 !$ ! *' 5 !��

! 2 0' 3 * 0 ? 0 2 .' !' " . 2 & ! + ? * / " .'

� . " 9 0) 9 .+ *,+ *$ 9 043 - ?+ 2 ! 0 ! + 3 !' . ! " * 0 ! ? " 2 * 0 + 3


Week 3


Lectu re 2 : T h e Mi crosoft Process

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References

• Mi croSoft Secrets; C u su m an o, Sel b y , Si m on & Sch u ster I n c. , 1 9 9 5

• H ow Mi crosoft B u i l d s Software; C u su m an oan d Sel b y , C om m u n i cati on s of th e A C M, J u n e 1 9 9 7

(not required reading)

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Philosophy

• M i c r o s o f t s t a r t e d a s s m a l l g r o u p o f " h a c k e r s "• O l d m e a n i n g o f " h a c k e r " : " l o n g -h a i r e d , u n k e m p t

t e c h n i c a l w i z a r d s " h a c k i n g a w a y a t c o d i n g . C r e a t i v e , v e r y g o o d a t g e t t i n g c o d e u p a n d r u n n i n g q u i c k l y .

• A s M i c r o s o f t g r e w , n e e d e d m o r e s t r u c t u r e w i t h o u t s t i f l i n g c r e a t i v i t y a n d t a l e n t

• W a t e r f a l l m o d e l a l s o t o o r i g i d w h e n u s e r r e q u i r e m e n t s c o n s t a n t l y e v o l v i n g

• " S y n c h -a n d -s a v e " m e t h o d o l o g y : a l l o w s d e v e l o p e r s t o w o r k i n s m a l l g r o u p s , f a i r l y i n d e p e n d e n t

• D a i l y b u i l d s a n d c o n s t a n t t e s t i n g k e e p g r o u p s f r o m d i v e r g i n g

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Interesting Numbers

• W i n d o w s 9 5 c o n t a i n s > 1 1 m i l l i o n l i n e s o f c o d e

• m o r e t h a n 2 0 0 p r o g r a m m e r s & t e s t e r s

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The Microsoft Triangle

• D e c i s i o n m a k i n g f o c u s e s o n t h r e e o f t h e d i m e n s i o n s o f q u a l i t y i n t h e e n d p r o d u c t :

– F u n c t i o n s s u p p o r t e d

– T i m e t o M a r k e t

– I m p l e m e n t a t i o n d e f e c t s r e m a i n i n g

• r a p i d d e v e l o p m e n t , d a i l y b u i l d s , t e s t i n g b u d d i e s

• e v o l v i n g r e q u i r e m e n t s , w o r k f r o m v i s i o n s t a t e m e n t

• h e a v y r e l i a n c e o n t e s t i n g , m u l t i p l e t e s t i n g s t r a t e g i e s

• w e l l e s t a b l i s h e d p l a n s a n d s c h e d u l e s

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Common Principles

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� �� ! " � � � � # $ � � � � ��

% & � �' � ( )� � �� * � � � )� + +� �

� ,� # -� � � � �. � � �/ ". �. �/ . � � � � � � � � � # !/ � �� # �

� 01 � � � � # �� . �. # � 032 # � � � � $ � � �/ . � � � � � � � � � #

� 4 ! � " � � # 5 ! � �. � � � �. �� !# �� . �. . # �. "� 6 �

% 7�98 � � ) � � � 8 �� +� � + � �

� 4. �� . / �� $ �� . � � �� 6 � � � �. �. # � � � �. # � 6 � � �. � � � �.

� � �. � # �� . � � �. � � � �. ". � �� / �� !� � ��: . �. � 5. � � � �. � �

% ; � �� )< ' � ( � � � �� +� ( ��

% = � 8 > � � � � � � ��

% ? � (' � � � (' � �� 8 +8 � ��

@ AB C B A CDE F AB G BH I DJ BK LK B E DJ J DJ

% M * �� 8 � ) � + � < � ( ) � N ' � � �

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Approach

• “ F i x ” p r o j e c t r e s o u r c e s

!#" $ %'& ( ) *'+ & )+ , &

- $ )" . / ) * / 0 $ &

• S e t i n t e n d e d s h i p d a t e

• D e f i n e m i l e s t o n e s b a c k w a r d s f r o m t a r g e t s h i p d a t e

• N o s e p a r a t e m a i n t e n a n c e g r o u p

10#2 & 3 0 .4 ," 5 & 5 0 . . & 2 / + ( ) 56" 4 / (& , & 7 3&

• T h r e e p h a s e s

8 /& ( 7 / 0#9 & 7+ + ( ) 74 :

; , 7 . . 0 .< + : 7 3&>= 5 & 9 & , )+ $ & . / + : 7 3&>= 3 / 7 % 0 , 0#? 7 / 0 ) . + : 7 3&

8 .4 ,6" 5 & %" * *& ( / 0 $ & 7 / & 74 : + : 7 3&

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Microsoft Process

Planning(3-12 months)

Stabilization(3-8 months)

Development(6-12 months)


Milestone 0

Subproject 1 Subproject 2 Subproject 3

Feature Complete

Visual Freeze

Release

Code Complete

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Microsoft Process

Release

Planning(3-12 months)


Development(6-12 months)


Milestone 0

Subproject 1 Subproject 2 Subproject 3

Code, test, optimize, stabilize

(6-10 weeks)

Integration test, debug(2-5 weeks)

Buffer time(2-5

weeks)

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Planning Phase (3-12 months)

• M a r k e t i n g , v i s i o n s t a t e m e n t , d e s i g n g o a l s

• I n i t i a l s p e c i f i c a t i o n

� ) . ,�� + (& , 0 $ 0 . 7 (� )" / , 0 . &

� �� / ) � � � 4 : 7 .< & 3 * ( ) $ 3 / 7 ( / / ) & . 5 ) * + ( ) � & 4 /

� + ( ) � & 4 / $ 7 . 7< & ( 3 & & + 0 / " + / ) 5 7 /&

� 7 . 3� & ( 3� " & 3 / 0 ) . 3 3" 4 : 7 3

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• P r o j e c t m a n a g e r s d o e x t e n s i v e p r o t o t y p i n g

! " #$ %&#(') * +, * ' #(-

! .�/ 01 ) '2 / ' 3 #2 " 4 0 #(5 $

��

Development Phase (6-12 months)

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/2 +2 * '2 '

$ �� % % &�

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')( *( +-, .( / 0 1 / 23 ( 4, 5 (

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6 9 0( / ( 5 8 4: 3 2, ; 03 : < < 1 / 2 3 (

5 /: <3 5, 48 = ( ; 3 : 3 2, ;

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4, ; 3 2 ; 8 , 8 0 +A@ : 0 3 ( 03 ( / 0 < 2 ; 5

3 B ( =

6 C DE , < 3 , 3 : + 5 ( *( +-, . = ( ; 3

. B : 0( 2 0 FG 8 < <( / H 3 2 = (

6 FI 2 08 : + < /( ( J( H

K LM NPOQ R STQ UPV WTQ XM YT S XQ O Z T V

K XOQ [?T V T X U W O X R STQ T \ R YM W UPO V

]Q O R ^

6 F_ ( : 3 8 /( 4, = . + ( 3 ( H

K X R ``ba X RV Y W UPO V M `

K WT S W S YT V MQ UPO S YM V Q RV

K S W U ` `c M S [ R ] S M V \

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6 Fd , 5 ( 4, = . + ( 3 ( H

K M ` ` XT M W RQ T S eOQ f M S

\ T S YQ U [?T \ UPV S ^T Y S M V \ R STQ

\?O Y S

K ^O UPV W ec TQ T [ R ] YO RV W

Sc O R ` \ [ T S WT M \ U `ba \ T Y ` UPV UPV ]

� ��

Stabilization Phase (3-8 months)

• 1/3 of total time in project

• E x tens iv e tes ting & d eb u g g ing

• N o new featu res

• “ Z ero b u g releas e”

– n o m o r e h i g h -s e v e r i t y b u g s h a v e b e e n f o u n d

– d e c i s i o n t o p o s t p o n e f i x i n g a l l r e m a i n i n g b u g s u n t i l n e x t r e l e a s e

� ��

Daily Build Process (1)

• C h e c k O u t

!" #%$ & ')( *+ ! # ( , + - , + . " * ( *+ / (

0 -" + 1 * ( 2 '" & 3 #%4 ( / 1 & , ')( " $ ( " , # + 2

0 1 . 3 ' # ! 3 ( / ( $ ( 3 + ! ( " , * & 2 * 5 ( * 6 + . ' , & 1 ( *+ / ( & ' , & 1 ( ' # 1 (

• I m p l e m e n t F e a t u r e

0 / ( $ ( 3 + ! ( " # 1 ! 3 ( 1 ( 2 ' , 5 # , 7 5 ( " + 8 2 * 5 & 29 ( ,

0 *+ . 3 / ' & 6( & -( 8 5 + . " , '+ , ( $ ( " & 3 / &: ,

• B u i l d P r i v a t e R e l e a s e

0 / ( $ ( 3 + ! ( " ; . # 3 / , + 8 2 !" # $ & ' ( *+ !: + - ' 5 ( !" + / . * ' 8 # ' 5 2 ( 8 3<:

# 1 ! 3 ( 1 ( 2 ')( / -( & ' . " ( ,• T e s t P r i v a t e R e l e a s e

0 / ( $ ( 3 + ! ( " ')( , ' , + 8 2 *+ !: + - !" + / . * '

� ��


• S y n c h C o d e C h a n g e s

0 *+ 1 ! & " ( !" #%$ & ')( *+ ! # ( , + - , + . " * ( - # 3 ( , ; & * 6 '+ 1 & , ')( "

$ ( " , # + 2

0 + ' 5 ( " / ( $ ( 3 + ! ( " , 1 &: 5 & $ ( 1 & / ( * 5 & 29 ( , # 2 ' 5 ( 1 ( & 2 ' # 1 (

• M e r g e C o d e C h a n g e s

0 . ! / & ')( !" #%$ & ')( *+ ! # ( , + - ,+ . " * ( - # 3 ( , '+ # 2 * 3 . / ( & 2: * 5 & 29 ( ,

-" + 1 + ' 5 ( " / ( $ ( 3 + ! ( " ,

• B u i l d P r i v a t e R e l e a s e

0 / ( $ ( 3 + ! ( " ; . # 3 / , + 8 2 *+ !: + - !" + / . * ' 8 # ' 5 ;+ ' 5 + 8 2

* 5 & 29 ( , & 2 / * 5 & 29 ( , + - + ' 5 ( " / ( $ ( 3 + ! ( " ,

• T e s t P r i v a t e R e l e a s e

0 ')( , ' '+ 1 & 6( , . " ( 2 ( 8 3 : # 1 ! 3 ( 1 ( 2 ')( / *+ / ( , ' # 3 3 8+ " 6 , 8 # ' 5

+ ' 5 ( " , � * 5 & 29 ( ,

��


• E x e c u t e Q u i c k T e s t

0 / + 2 ( + 2 !" # $ & ')( " ( 3 ( & , (

0 5 #9 5 3 : & . '+ 1 & ')( /

0 1 & 6( , , . " ( 2 ( 8 * 5 & 29 ( ,

/ + 2 + ' # 2 ')( " -( " ( 8 # ' 5

; & , # * - . 2 * ' # + 2 & 3 # ': + -

!" + / . * '

0 / + ( , 2 + '')( , ' 2 ( 8 -( & ' . " (

/ # " ( * ' 3 :

0 ( � 9 �� . # * 6 ')( , ' + 2 � � � ��

' & 6( , � 1 # 2 . ')( ,

0 & 3 ,+ * & 3 3 ( / , 1 + 6( ')( , ' + "

" ( 9 " ( , , # + 2 ')( , '

• C h e c k i n

0 / ( $ ( 3 + ! ( " + - - # * # & 3 3 :

* 5 ( * 6 , 5 # , !" # $ & ')( *+ ! # ( ,

# 2 '+ ' 5 ( 1 & , ')( " $ ( " , # + 2

0 5 & , '+ ,: 2 * 5 & 2 / 1 ( " 9 (

&9 & # 2 # 2 * & , ( + - - . " ' 5 ( "

* 5 & 29 ( ,

0 # - *+ 2 - 3 # * ' ,� 1 &: 5 & $ ( '+

8 # ' 5 / " & 8 * 5 & 29 ( ,

0 / ( & / 3 # 2 ( -+ " * 5 ( * 6 # 2

� � � ��

��

� ��


• G e n e r a t e D a i l y B u i l d

– a f t e r c h e c k i n d e a d l i n e

– b u i l d m a s t e r g e n e r a t e s c o m p l e t e b u i l d o f p r o d u c t f r o m m a s t e r v e r s i o n

� ! ""$# % & % ! ' ")( *)+ ' " %,

� ! -. # / 0+ # 0 0 -+ "*)+ ' " %

1 23 24 5 6 27 7 28 9 2 7 : ; < 5 6 : = < 6 2 > 6 27 67

1 < 7 7 5 8 27 ? < 7 9 4 ; 5 @ 4 6 9 : @ < A 9 6CB D :8 E7 4 :8 8 24 6 A B

1 = < E 27 > < 9 A B ? 5 9 A > <F < 9 A < ? A 2 6 : < A A G8 : H 24 6 7 6 < ; ;

� ��

Role of Program Managers

• T y p i c a l s t r u c t u r e :

– m a n a g e r s m a k e a l l d e s i g n d e c i s i o n s : s t r u c t u r e o f c o d e a n d h o w t o d i v i d e t a s k s

– d e v e l o p e r s f o l l o w i n s t r u c t i o n s & t u r n d e s i g n i n t o c o d e

• M i c r o s o f t :

– d e v e l o p e r s i n v o l v e d i n d e s i g n

– m a n a g e r o r g a n i z e s , k e e p s r e c o r d s , m a k e s s u r e d e c i s i o n s g e t m a d e

– s u c c e s s d e p e n d s o n p e r s o n a l i t i e s

��

Testing (1)

• q u i c k t e s t s o n d a i l y b u i l d

• d e v e l o p e r s c r e a t e d e b u g v e r s i o n s

! " ! # $$&% ')( * +-, . +-/ ', 0/ # $1 # ' # " ' 0 ! 2 ' ! 0, "

3 +-4 5 0( *, 4 , 4 ( 0% ! " #6 , #/ 1 , 7, 2 ! ' + ( / " 5, , 1• u s e a s s e r t i o n s “ i f t h e n ” t e s t s

3 . 8 , / 4 # 9 +/ 6 # " " ! 4 5 ' + ( / " # : ( ! '1 # ' # " ')( 0, 1 , $ ", . 8 , 0, +/

5 0( 6 0 # 4

• i n s t r u m e n t a t i o n f o r u s e r t e s t i n g

3 2 # 5 ' ! 0, " 2 ( 4 4 #/ 1 " ! ", 0 " ", $ , 2 '

3 2 # 5 ' ! 0, " 2 ( 0 0, " 5 ( / 1 +-/ 6 " ( ! 0 2, 2 ( 1 , " ' # ', 4 , / ' " ' 8 # ' 6 , '

, 7, 2 ! ', 1

� ��

Testing (2)

• u s a b i l i t y t e s t i n g

– l a b w i t h “ p e o p l e o f f t h e s t r e e t ”

– u s e r i n t e r f a c e s t e s t e d

• w e e k l y t e s t r e l e a s e s

– t o t e s t i n g g r o u p f o r t h o r o u g h t e s t i n g

– u s e h i g h l y s t r u c t u r e d s c r i p t s

– “ g u e r r i l l a ” t e s t i n g

� ' 0% ')( : 0, # 9 ' 8 , 5 0( 1 ! 2 '

� ��

Testing (3)

• t e s t i n g b u d d i e s– w o r k s i d e b y s i d e w i t h d e v e l o p e r s

– d e v e l o p e r s h a r e s p r i v a t e r e l e a s e w i t h h i s t e s t i n g b u d d y

– d o p r i v a t e r e l e a s e t e s t i n g b e f o r e c o d e g o e s t o d a i l y b u i l d

• o t h e r k i n d s– p e r f o r m a n c e t e s t i n g

– i n t e r n a l u s a g e

– b e t a t e s t i n g

��

Observations From Book (1)

• l i t t l e a r c h i t e c t u r a l d o c u m e n t a t i o n

– s o u r c e c o d e i s o n e m a i n d o c u m e n t

– t r y t o k e e p c o d e a s s i m p l e a s p o s s i b l e

– compartmentalize code

• v e r y l i t t l e c o d e c o m m e n t s

– u s es “ H u ng arian” ru les f or v ariab le naming

� ��

– h alf lif e of s ou rce code is as little as 1 8 month s

� ��


• C u s u m a n o & S e l b y r e c o m m e n d :

– m o r e u s e o f m e t r i c s

• d o u s e b u g c o u n t s

– d e s i g n a n d c o d e r e v i e w s

• i n t e n s i v e c o d e i n s p e c t i o n s

• d e t e c t a n d f i x p r o b l e m s b e f o r e i n c o r p o r a t e d i n t o p r o d u c t

• r e f i n e p r o d u c t a r c h i t e c t u r e

• e d u c a t e j u n i o r d e v e l o p e r s

� ��


• " S y n c h a n d s a v e " m a k e s i t s i m p l e r t o r e a c t t o c u s t o m e r f e e d b a c k t h r o u g h d e v e l o p m e n t

• W o r k s w e l l f o r s o m e k i n d s o f a p p l i c a t i o n s ( W o r d , E x c e l )

• O p e r a t i n g s y s t e m s ( W i n d o w s ) & a p p l i c a t i o n s s u c h a s i n t e r a c t i v e v i d e o a r e m o r e " t i g h t l y c o u p l e d "

� ��

• T h e s e p r o g r a m s w o u l d b e n e f i t f r o m m o r e u p -f r o n t p l a n n i n g


Week 3


Lectu re 3 : Last D etai l s, R ev i ew

�� recall abstract classes can contain

• attributes• concrete methods • abstract methods

mixture of abstract and concrete

Topic 1: Interfaces

an interface is like an abstract class but contains only abstract methods – no attributes, no concrete methods

completely abstract

an interface is a skeleton or template for a classspecifies functionality the class must providenothing about implementation

� �� public interface Comparable {public int compareTo(Object o);

}

Example From the API

Note: all methods in an interface are abstract.Don't need keyword abstract in declaration

Terminology:you extend an abstract classyou implement an interface

��

String & Comparable

Man y A PI cl asses i m p l em en t ComparableE x am p l e: String implements Comparable

-- it has acompareTo method

public class String implements Comparable { ....// body of class includes a concrete// compareTo method

}

�� Suppose we want to be able to compare 2 employees

on the basis of the amount of pay owed to them

Add acompareTo method to Employee and addimplements Comparable

to the class header

Employee & Comparable

��

Employee & Comparable

public class Employee implements Comparable {public int compareTo(Object obj) {

if (obj instanceof Employee) {Employee other = (Employee) obj;if (payOwed == other.payOwed)

return 0;else if (payOwed < other.payOwed)

return -1;else

return 1;}else {

return 1; // arbitrary value} // end if

} // end compareTo.. rest of Employee class

� �� recall: a class can extend only one other class

Multiple Inheritance Revisited

but a class can implement many interfaces

distinction between abstract classes & interfacesis Java's answer to multiple inheritance

gives most of functionality of multiple inheritancewithout the implementation headaches

��

Multiple Inheritance Revisited

String implements 2 interfaces:ComparableSerializable (related to I/O)

Syntax:public class String implements Comparable, Serializable {

A class can extend another class and implement interfaces:public class Executive extends Employee implements Comparable {

��

UML For Interfaces

One way to show interface in Java:

class box as before, with <<Interface>> stereoty p e

n ote: n o attribu tes com p artm en t

<<interface>>Comparable

compareTo(Object o): int

��

Showing "implements"

U se a d ashed g en eraliz ation arrow from a class

to an in terface it im p lem en ts

<<interface>>Comparable

compareTo(Object o): int

Employee

��

Another Way to Show Interfaces

Interface is represented by a small circle

w ith name o f interface

S o lid line betw een interface and implementing class

EmployeeComparable

��

Generic Code

Interfaces are v ery u sefu l fo r w riting

g eneric ( g eneral-pu rpo se) co de

E x ample: so rting

M eth o d to so rt array o f E mplo yees u sefu l

o nly fo r o ne pu rpo se

A no th er k ind o f o bj ect: mu st w rite a new

so rting meth o d

M u ch better: g eneral meth o d fo r so rting O bj ects

� ��

Generic Sorting

void sort(Object arr[])

p roblem : n eed to k n ow how to com p are p airs of obj ects

n o g en eral an swer

solu tion : we will on ly sort array s of obj ects that hav e a

com p areT o m ethod

– i. e. obj ects that im p lem en t Comparable

n ow sig n atu re is void sort(Comparable arr[])

in sid e m ethod , we can say

if (arr[i].compareTo(arr[j]) < 0) ....

�� API class Arrays provides useful static methods for arrays

(search, sort, fill with value, etc.)

API Sorting Method

one of the methods:static void sort(Comparable[] a)

This class is in the API package java.util.

��

Using Arrays.sort

Employee company[] = new Employee[SIZE];

// code to fill company array

Arrays.sort(company);

T his is leg al becau se the Employee class im p lem en ts Comparable

S orts the array accord in g to compareTo m ethod in Employee

S o p erson owed the least m on ey com es first,p erson owed the m ost m on ey com es last

�� Recall Java's rules about constructors.

Rule 1: If your class has no constructors at all, Java creates default: no parameters, does nothing. All fields left at 0 or null.

Topic 2: Details About Constructors

Rule 2: You can define your own constructor, or lots of overloadedconstructors with different numbers & types of parameters.

Rule 3: If you define any constructors, you don't get the default. Ifyou want a no-parameter constructor in addition to others, youmust write it yourself.

� ��

public class C {int x;... // no constructors in this class

}...

C obj = new C(); // legal, obj.x = 0

Example

public class C {int x;public C (int val) { x = val; }....

}...

C obj1 = new C(13); // legal, obj1.x = 13C obj2 = new C(); // illegal!

� ��

You've seen that you may call the constructor of parent class using keyword super.

Calling "super" constructor

public Salesperson(String empName, String empTitle, double empWage, double empRate) {

super(empName, empTitle, empWage); // Employee constructorrate = empRate;

} // end constructor

In fact, Java requires a call to a parent constructor.If you don't make one as first line of child class' constructor,

Java adds call to super().

� �� What if parent class doesn't have a no-parameter constructor?

Potential Problem

public Salesperson(String empName, String empTitle, double empWage, double empRate) {

name = empName;title = empTitle;wage = empWage;rate = empRate;

} // end constructor

compiler inserts call to super().

super();

But parent class (Employee) has only 1 constructor and it takes3 parameters! Result: weird error message.

�� You must either:

• give the parent class a no-parameter constructor OR• make sure all child class constructors call super()

as first statement

Moral

��

Review For Midterm

Topics:– O O P ( som e r e v ie w , som e n e w )– U M L– S of t w a r e P r oce ss

L og ist ics:– M on d a y in se ct ion w h ere y o u are reg istered– w il l b e 2 d if f e r e n t v e r sion s– m a y b r in g a " ch e a t sh e e t " ( 8 . 5 x 1 1 " , b ot h sid e s)– w e w il l b e st r ict a b ou t n oise & m ov e m e n t– pol icy : w e w il l n ot r e v ie w pa pe r s w it h

• e r a se r sm u d g e s• w h it e -ou t

��

UML "Cheat Sheet" (1)

Employee

name: Stringwage: double

pay(hours: double)amountToPay(): double

class diagram

Mary: Executive

name = "Mary"wage = 35

object diagram

Employee Officeoccupant workplace

worksIn

association with name, roles, quantifiers

1..* 1

� ��


A r r ow s:

��

� � ��

� � � � � � � � ��

� � � � � � � ��

� � ��

��

��


Abstract Classes & Methods: use italics or write "abstract"

I n terf ace: use < < in terf ace> > stereoty p e or

rep resen t by sm all circle ( n o m ethods shown )

CD

Song

*

1..*

track number qualifier

Resource

Skill

*

*Experience

association class

��

Use Case Diagram

circles are "use cases"stick figures are "actors"non-human actor:

box with <<actor>>

��

Sequence Diagram

! "# $! &% '(

)% * + ! ,.- ! % / / '0 1% ' 2 ! &% '

1% ' 2 ! &% ' $ 34(

1% ' 2 ! &% ' ' )4# $ 1 5 "! -

Customer Cashier CookPlace order

Give money

Send foodAnnounce price

Give food

Request food

Ask for more money

[until enough money]

cisc 323 introduction to software...

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