Object Modeling Approach

Transcription

1 Object Modeling Approach

2 Defi e object mode Ide tify objects a d c asses Prepare data dictio ary Ide tify associatio s a d aggregatio s Ide tify attributes of objects a d i ks Orga ize a d simp ify usi g i herita ce Iterate a d refi e the mode Group c asses i to modu es Object Modeling Approach Start ith a prob em stateme t High- eve requireme ts

3 The Home Heating System Water Pump Water Valve Hot Water Burner Controller Home Fuel Valve Off Fuel On Control Panel Temp Sensor

4 Home Heating Requirements The purpose of the software for the Home Heating System is to control the heating system that heats the rooms of a house. The software shall maintain the temperature of each room within a specified range by controlling the heat flow to individual rooms. The soft are sha co tro the heat i each room The room sha be heated he the temperature is 2F be o desired temp The room sha o o ger be heated he the temperature is 2F above desired temp The f o of heat to each room sha be i dividua y co tro ed by ope i g a d c osi g its ater va ve The va ve sha be ope he the room eeds heat a d c osed other ise The user sha set the desired temperature o the thermostat The operator sha be ab e to tur the heati g system o a d off The fur ace must ot ru he the system is off

5 Home Heating Requirements The purpose of the software for the Home Heating System is to control the heating system that heats the rooms of a house. The software shall maintain the temperature of each room within a specified range by controlling the heat flow to individual rooms. Whe the fur ace is ot ru i g a d a room eeds heat, the soft are sha tur the fur ace o To tur the fur ace o the soft are sha fo o these steps ope the fue va ve tur the bur er o The soft are sha tur the fur ace off he heat is o o ger eeded i a y room To tur the fur ace off the soft are sha fo o these steps c ose fue va ve tur bur er off

6 Identify Object Classes Requirements Statements Extract Nouns Tentative Object Classes Eliminate Spurious Classes Object Classes Water Pump Candidate Classes Controller Hot Water furnace Burner Fuel Valve Fuel operator Home Heating System house thermostat room heating system temperature desired temp heat on-off switch Temp Sensor Home Control Panel Water Valve software range

7 Eliminate Bad Classes Redu da t c asses C asses that represe t the same thi g ith differe t ords Irre eva t c asses C asses e simp y do ot care about Vague c asses C asses ith i -defi ed bou daries Operatio s Seque ces of actio s are ofte mistake for c asses Ro es The ame of a c ass shou d ref ect hat it is, ot the ro e it p ays Imp eme tatio detai s Save that for imp eme tatio Attributes Thi gs that describe i dividua objects

8 Eliminate Classes Redundant Irrelevant Vague Attributes heating system Fuel software heat house desired temp user temperature Hot Water heat flow home Operations Roles range Implementation None None None Fuel Valve Water Pump furnace thermostat operator on-off switch Burner room Controller Home Heating System Temp Sensor Water Valve Control Panel

9 Classes After Elimination Fuel Valve Burner Water Pump Room Home Heating System Thermostat Furnace Temp Sensor Water Valve Operator on-off switch Controller Control Panel

10 Prepare Data Dictionary Water Ta k The storage ta k co tai i g the ater that circu ates i the system. Pump-1 The pump pumpi g ater from the Water Ta k to the radiators i the rooms

11 Possible Associations A room co sists of a thermometer a d a radiator Not much i formatio from the prose requireme ts A ot of i formatio from the system desig A radiator co sists of a va ve a d a radiator e eme t The home heati g system co sists of a fur ace, rooms, a ater pump, a co tro pa e, a d a co tro er The fur ace co sists of a fue pump a d a bur er The co tro pa e co sists of a o -off s itch a d a thermostat The co tro er co tro s the fue pump The co tro er co tro s the bur er The co tro er co tro s the ater pump The co tro er mo itors the temperature i each room The co tro er ope s a d c oses the va ves i the rooms The operator sets the desired temperature The operator tur s the system o a d off The co tro er gets otified of the e desired temperature

12 Object Model Home Heating System Control Panel Furnace Water Pump Runs On-Off Switch Thermostat Burner Fuel Valve Pushes Adjusts 1..* Room Notifies Operator Opens/Closes Ignites Water Valve Temp Sensor 1..* Monitor Actuates Controller

13 Object Model Home Heating System Control Panel Furnace Water Pump Runs On-Off Switch Thermostat Burner Fuel Valve Pushes Adjusts 1..* Room 1..* Notifies Operator Heats Opens/Closes Ignites Water Valve Temp Sensor Actuates 1..* Monitor Controller

14 Attributes Thermostat desired-temp On-Off switch setting Temp Sensor temperature

15 Final OO Model Home Heating System Control Panel Furnace Water Pump Runs On-Off Switch Thermostat Burner Fuel Valve Notifies setting desired-temp Pushes Adjusts Operator 1..* Room Heats 1..* Opens/Closes Ignites Water Valve Temp Sensor Actuates temperature 1..* Monitor Controller

16 Iterate the Model Keep o doi g this u ti you, your customer, a d your e gi eers are happy ith the mode Iterate

17 Operation vs Method Operation: specifies object behavior Service: represe ted by set of oper s. Message: object requests executio of a oper. from a other object by se di g it mesg. Method: mesg is matched up ith method defi ed by the c ass to hich the receivi g object be o gs (or a y of its superc asses) Operations of c ass are pub ic services offered by c ass. Methods of its c asses are the imp eme tatio s of these operations.

18 OO Using UML: Dynamic Models Defining how the objects behave

19 Overview The object mode describes the structure of the system (objects, attributes, a d operatio s) The dy amic mode describes ho the objects cha ge state (ho the attributes cha ge) a d i hich order the state cha ges ca take p ace Severa mode s used to fi d the appropriate dy amic behavior I teractio diagrams Activity diagrams State Diagrams Uses fi ite state machi es a d expresses the cha ges i terms of eve ts a d states

20 Interaction Diagrams

21 We Will Cover Why i teractio diagrams? Seque ce diagrams Capturi g use-cases Dea i g ith co curre cy Co aboratio diagrams Whe to use hat Whe to use i teractio diagrams

22 Co aboratio diagrams High ight the structure of the compo e ts (objects) i vo ved i the i teractio Different Types of Interaction Diagrams A I teractio Diagram typica y captures a use-case A seque ce of user i teractio s Sequence diagrams High ight the seque ci g of the i teractio s bet ee objects

23 Home Heating Use-Case Use case: Power Up Actors: Home Owner (initiator) Type: Primary and essential Description: The Home Owner turns the power on. Each room is temperature checked. If a room is below the the desired temperature the valve for the room is opened, the water pump started, the fuel valve opened, and the burner ignited. If the temperature in all rooms is above the desired temperature, no actions are taken. Cross Ref.: Requirements XX, YY, and ZZ Use-Cases: None

24 Sequence Diagrams Use * to A Home denote Owner: the On-Off Switch: the Controller: a Room: iterationthe Water Pump: HomeOwner OnOffSwitch Controller Room WaterPump Use the left column to offer comments about the messages System On poweron() *[for all rooms] tempstatus:=checktemp() Synchronous message [tempstatus == low] pumpon() Response to synchronous message [tempstatus == low] openvalve() [tempstatus == low] startburner() Guard for message

25 Example from Fowler An Entry Window: Window An Order: Order An Order: Order A Stock Item: StockItem prepare() *[for all order lines] prepare() hasstock := check() [hasstock] remove() needsreorder := needstoreorder() [needsreorder] new [hasstock] new A Reorder Item: ReorderItem A Delivery Item: DeliveryItem

26 Concurrency new a Transaction new a Transaction Coordinator new a first Transaction Checker new ok a second Transaction Checker alldone? ok allvalid alldone?

27 Another Example a Home Owner the On-Off Switch the Controller the Water Pump System On poweron() *[for each room in house] new a Room checktemp() [templow] pumpon() [templow] openvalve() [templow] startburner() templow

28 Comment the Diagram When the owner turns the system on a Home Owner the On-Off Switch the Controller the Water Pump the on switch notifies the controller System On poweron() The controller creates a room object for each room in the building The rooms sample the temperature in the toom every 5 s. When a low temp is detected the room notifies the controller. *[for each room in house] new [templow] pumpon() [templow] openvalve() [templow] startburner() templow a Room checktemp() MH

29 Example from Fowler An Entry Window: Window An Order: Order An Order: Order A Stock Item: StockItem prepare() *[for all order lines] prepare() hasstock := check() [hasstock] remove() needsreorder := needstoreorder() [needsreorder] new [hasstock] new A Reorder Item: ReorderItem A Delivery Item: DeliveryItem

30 Collaboration Diagrams :Order Entry Window 1 : prepare() :Order 2 : *[for all order lines]: prepare() 3 : hasstock := check() 5 : needsreorder := needstoreorder() 7 : [hasstock] :new Winter line : Order Line 4 : [hasstock]: remove() Winter stock : Stock Item 6 : [needsreorder]: new :Delivery Item a Reorder Item MH

31 Conditional Behavior Somethi g you i e cou ter tryi g to capture comp ex use-cases The user does something. If this something is X do this If this something is Y do something else If this something is Z Sp it the diagram i to severa Sp it the use-case a so Use the co ditio a message Cou d become messy Remember, clarity is the goal!

32 Comparison Both diagrams capture the same i formatio Peop e just have differe t prefere ces We prefer seque ce diagrams They c ear y high ight the order of thi gs I va uab e he reaso i g about mu ti-taski g Others ike co aboratio diagrams Sho s the static structure o Very usefu he orga izi g c asses i to packages We get the structure from the C ass Diagrams

33 When to Use Interaction Diagrams Whe you a t to c arify a d exp ore si g e use-cases i vo vi g severa objects Quick y becomes u ru y if you do ot atch it If you are i terested i o e object over ma y use-cases -- state transition diagrams If you are i terested i ma y objects over ma y use cases -- activity diagrams

34 State Diagrams

35 State Machi es We Will Cover A a ter ate ay of capturi g sce arios olarge c asses of sce arios Sy tax a d Sema tics Whe to use state machi es

36 Events, Conditions, and States Eve t: somethi g that happe s at a poi t i time o Operator presses se f-test butto o The a arm goes off Co ditio : somethi g that has a duratio o The fue eve is high o The a arm is o State : a abstractio of the attributes a d i ks of a object (or e tire system) o The co tro er is i the state se f-test after the se f-test butto has bee pressed a d the reset-butto has ot yet bee pressed o The ta k is i the state too- o he the fue eve has bee be o eve - o for a arm-thresho d seco ds

37 Making a Phone Call Scenario Context for example: (shorter version) To make a ca, the ca er ifts receiver. The ca er gets a dia to e a d the ca er dia s digit (x). The dia to e e ds. The ca er comp etes dia i g the umber. The ca ee pho e begi s ri gi g at the same time a ri gi g begi s i ca er pho e. Whe the ca ee a s ers the ca ed pho e stops ri gi g a d ri gi g e ds i ca er pho e. The pho es are o co ected. The ca er ha gs up a d the pho es are disco ected. The ca ee ha gs up.

38 Partial Class Diagram Line 1 Connected by 1 Caller Phone 1 Connected by Callee 1

39 Event Trace Phone:Caller Line:theLine Phone:Callee caller lifts receiver dial tone begins dials digit (3) dial tone ends dials digit (2) dials digit (3) dials digit (4) dials digit (5) ringing tone tone stops phones connected phones disconnected callee hangs up phone rings callee answers ringing stops phones connected caller hangs up phones disconnected

40 State Diagram for Scenario on-hook Idle off-hook Dial tone digit(x) digit(x) Dialing Ringing Connected valid-number Disconnected called-phone-answers called-phone-hangs-up

41 Scenario 2 Phone:Caller Line:theLine Phone:Callee caller lifts receiver dial tone begins dials digit (3) dial tone ends dials digit (2) dials digit (3) dials digit (4) dials digit (5) busy tone caller hangs up

42 Modified State Machine on-hook Idle off-hook Dial tone digit(x) Busy tone digit(x) number-busy routed Ringing Dialing valid-number Connecting Connected Disconnected called-phone-answers called-phone-hangs-up

43 Conditions Sometimes the state transitions are conditional digit(x) Dialing digit(x) on-hook digit(x) [x = 8] Busy tone Dial tone (external) Idle off-hook Dial tone valid-number number-busy Ringing routed digit(x) [x!= 8] Dialing Connecting digit(x) valid-number

44 Operations (AKA Actions) Idle Actio s are performed he a tra sitio is take or performed hi e i a state Actio s are termi ated he eavi g the state on-hook on-hook on-hook on-hook Busy tone do/ busy tone on-hook on-hook / disconnect line on-hook off-hook Dial tone do/ sound dial tone Ringing Connected digit(x) Disconnected Dialing Connecting digit(x) number-busy valid-number routed do/ find connection do/ ring bell called-phone-answers / connect line called-phone-hangs-up / disconnect line

45 Hierarchical State Machines Group states ith simi ar characteristics E ab es i formatio hidi g Simp ifies the diagrams on-hook Make Call Idle Establish call Busy tone do/ busy tone on-hook / disconnect line on-hook off-hook number-busy dial(x) [x is a digit] Dialing Connected Disconnected Dial tone do/ sound dial tone valid-number Connecting do/ find connection routed Ringing do/ ring bell dial(x) called-phone-answers / connect line called-phone-hangs-up / disconnect line on-hook dial(x) [x = *] Voice Mail

46 Information Hiding on-hook on-hook / disconnect line on-hook Idle off-hook dial(x) [x is a digit] Make Call Establish call Connected Disconnected Dial tone do/ sound dial tone called-phone-answers / connect line called-phone-hangs-up / disconnect line on-hook dial(x) [x = *] Voice Mail Establish call number-busy Busy tone do/ busy tone Dialing valid-number Connecting do/ find connection routed Ringing do/ ring bell dial(x)

47 Concurrency Some states represe t severa co curre t co cepts Co curre cy is supported by the state machi es Co curre t state machi es are separated by dashed i es Visual Alarm On Aural Alarm On Alarms Disabled out-of-bounds-event Alarms Enabled reset visual-on reset aural-on Off Off

48 State Machines - Summary Eve ts i sta ces i time Co ditio s co ditio s over time States abstractio of the attributes a d associatio s Tra sitio s Takes the state machi e from o e state to the ext o Triggered by eve ts o Guarded by co ditio s o Cause actio s to happe I ter a actio s somethi g performed i a state Hierarchies a o s abstractio a d i formatio hidi g Para e ism mode s co curre t co cepts

49 When to use State Machines Whe you a t to describe the behavior of o e object for a (or at east ma y) sce arios that affect that object Not good at sho i g the i teractio bet ee objects Use i teractio diagrams or activity diagrams Do ot use them for a c asses Some methods prescribe this Very time co sumi g a d questio ab e be efit

50 HERE

51 Coming up with the State Diagrams

52 Modeling Approach Prepare sce arios Work ith the customer Start ith orma sce arios Add ab orma sce arios Ide tify eve ts (ofte messages) Group i to eve t c asses Dra some seque ce diagrams Fi d objects ith comp ex fu ctio a ity you a t to u dersta d better Bui d a state diagram for the comp ex c asses

53 Scenario-1 Room Controller Fuel Valve Burner Water Pump request-temp Every 5s respond-temp open-valve Temp Low Every 5s Temp Normal open-water-valve request-temp respond-temp close-water-valve start-burner pump-on pump-off stop-burner close-valve

54 Scenario-1, v2 Room Controller Fuel Valve Burner Water Pump request-temp Every 5s respond-temp Temp Low open-water-valve open-valve start-burner pump-on request-temp Every 5s Temp Normal respond-temp pump-off close-water-valve close-valve stop-burner

55 Scenario-2 Every 5s Desired temp change Every 5s Temp Low Every 5s Control Panel Room request-temp respond-temp desired-temp-change request-temp respond-temp Controller open-water-valve request-temp respond-temp open-valve Fuel Valve start-burner pump-on pump-off Burner Water Pump Temp Normal close-water-valve close-valve stop-burner

56 Scenario-2, v2 Every 5s Desired temp change Every 5s Temp Low Every 5s Control Panel Room request-temp respond-temp desired-temp-change request-temp respond-temp Controller open-water-valve request-temp respond-temp open-valve Fuel Valve start-burner pump-on pump-off Burner Water Pump Temp Normal close-watervalve close-valve stop-burner

57 Dynamic Model Water Pump pump-on On Off pump-off Fuel Valve Open open-valve close-valve Closed Burner On start-burner stop-burner Off

58 More Dynamic Model Water-Valve open-water-valve/ wv-open Valve Room Temp-Sensor Idle request-temp temp-report(x)/ respond-temp(x) close-water-valve/ wv-close Processing Request

59 Even More Dynamic Model TemperatureControl Controller respond-temp(x)[x>desired-temp+2]/stop-heating timeout(5s)/ request-temp Temp-Low Temp-Normal timeout(5s)/ request-temp respond-temp(x)[x<desired-temp-2]/start-heating HomeHeatingSystemControl timeout(1s)/ pump-on,open-water-valve All-Running Burner-On timeout(1s)/start-burner Fuel-Open start-heating/open-valve All-Off stop-heating/ pump-off,close-water-valve Water-Off Fuel-Off timeout(1s)/stop-burner timeout(1s)/close-valve

60 Even More Dynamic Model, v2 TemperatureControl Controller respond-temp(x)[x>desired-temp+2]/stop-heating timeout(5s)/ request-temp Temp-Low Temp-Normal timeout(5s)/ request-temp respond-temp(x)[x<desired-temp-2]/open-water-valve,start-heating HomeHeatingSystemControl timeout(1s)/ pump-on,open-water-valve All-Running Burner-On timeout(1s)/start-burner Fuel-Open start-heating/open-valve All-Off stop-heating/ pump-off,close-water-valve Water-Off Fuel-Off timeout(1s)/stop-burner timeout(1s)/close-valve, close-water-valve

61 Identify Key Operations Operatio s from the object mode Accessi g a d setti g attributes a d associatio s (ofte ot sho ) Operatio s from eve ts A eve ts represe t some operatio Operatio s from actio s a d activities Actio s a d activities represe t some processi g activity ithi some object Operatio s from fu ctio s Each fu ctio typica y represe t o e or more operatio s Shoppi g ist operatio s I here t operatio s ( hat shou d be there)

62 Complete OO Model Home Heating System Control Panel operating() target-temp() Furnace Water Pump pump-on() pump-off() Runs Notifies On-Off Switch Thermostat setting desired-temp 1..* Room Pushes Adjusts Operator Burner Start-burner() Stop-burner) open-water-valve() close-water-valve() 1..* room-temp() 1..* Water Valve Temp Sensor temperature open-valve() close-valve() Ignites Heats Fuel Valve Monitor Opens/Closes Controller start-heating() stop-heating()

63 Iterate the Model Keep o doi g this u ti you, your customer, a d your e gi eers are happy ith the mode Iterate

64 Activity Diagrams

65 We Will Cover History of activity diagrams i UML A high y perso a perspective Activity diagrams S im a es Whe to use activity diagrams Whe ot to

66 Activity Diagrams Sho s ho activities are co ected together Sho s the order of processi g Captures para e ism Mecha isms to express Processi g Sy chro izatio Co ditio a se ectio of processi g

67 Why Activity Diagrams Very good questio Not part of a y previous (UML re ated) method To make UML more i c usive of busi ess mode i g eeds Suitab e for mode i g of busi ess activities UML a d OO is becomi g more preva e t i busi ess app icatio s Object frame orks are maki g a i road Stay ithi o e deve opme t approach a d otatio Notatio simi ar to process mode i g a guages

68 Coffee Example Find Beverage [no coffee] Decision no coke] [ [no soda] [found coffee] [found soda] [found coke] Put Coffee in Filter Add Water to Reservoir Get Cups Get can of soda Get Can of Coke Put Filter in Machine Turn On Machine ^coffepot.turnon Brew Coffee Drink Beverage Pour Coffee MH

69 HACS Use-Cases Use case: Distribute Assignments Actors: Instructor (initiator), Student Type: Primary and essential Description: The Instructor completes an assignment and submits it to the system. The instructor will also submit the delivery date, due date, and the class the assignment is assigned for. The system will at the due date mail the assignment to the student. Cross Ref.: Use-Cases: Requirements XX, YY, and ZZ Configure HACS must be done before any user (Instructor or Student) can use HACS

70 Activity Diagrams for Use Write Assignment Cases [submission time] Write Solution Submit Assignment Mail Assignment Solve Assignment Submit Solution Submit Solved Assignment Grade Assignment Mail Solution Review Solution Hit the Pub

71 Swimlanes (Who Does What?) Instructor HACS Student Write Assignment [submission time] Write Solution Submit Assignment Mail Assignment Solve Assignment Submit Solution Submit Solved Assignment Grade Assignment Mail Solution Review Solution Hit the Pub

72 When to Use Activity Diagrams Usefu he A a yzi g a use case (or co ectio of use cases) U dersta di g orkf o i a orga izatio Worki g ith mu ti-threaded app icatio s o For i sta ce, process co tro app icatio s Do ot use activity diagrams o To figure out ho objects co aborate o See ho objects behave over time

73 Approaching a Problem Where do we start? How do we proceed?

74 Where Do We Start? (Early Requirements) Start ith the requireme ts Capture your goa s a d possib e co strai ts E viro me ta assumptio s Use-case a a ysis to better u dersta d your requireme ts Fi d actors a d a first rou d of use-cases Start co ceptua mode i g Co ceptua c ass diagram I teractio diagrams to c arify use-cases State diagrams to u dersta d major processi g

75 How Do We Continue? (Late Requirements) Refi e use-cases Possibly some real use-cases o Usi g i terface mockups Refi e (or restructure) your c ass diagram Based o your hard are architecture o For i sta ce, c ie t server Refi e a d expa d your dy amic mode U ti you are comfortab e that you u dersta d the required behavior Ide tify most operatio s a d attributes

76 How Do We Wrap Up? (Design into Implementation) Refi e the c ass diagram based o p atform a d a guage properties Navigabi ity, pub ic, private, etc C ass ibraries Ide tify a operatio s Not the trivia get, set, etc. Write a co tract for each operatio Defi e a co ectio of i varia ts for each c ass Imp eme t

77 Requirements Products Specificatio docume t Agreeme t bet ee customer a d deve oper Va idatio criteria for soft are Pre imi ary users ma ua Prototype If user i teractio is importa t If resources are avai ab e Revie by customer a d deve oper Iteratio is a most a ays required

78 Analysis: Steps to follow Obtai a prob em stateme t Deve op use cases (depict sce arios of use) Bui d a object mode a d data dictio ary Deve op a dy amic mode state a d seque ce diagrams Verify, iterate, a d refi e the mode s Produce a a ysis docume t (e.g., SRS)

79 Use Cases High- eve overvie of system use Ide tify sce arios of usage Ide tify actors of the system: Exter a e tities (e.g., users, systems, etc.) Ide tify system activities Dra co ectio s bet ee actors a d activities Ide tify depe de cies bet ee activities (i.e., exte ds, i c udes)

80 Analysis: Object Model Orga izatio of system i to c asses co ected by associatio s Sho s the static structure Orga izes a d decomposes system i to more ma ageab e subsystems Describes rea or d c asses a d re atio ships

81 Analysis: Object Model Object mode precedes the dy amic mode because static structure is usua y better defi ed ess depe de t o detai s more stab e as the system evo ves

82 Analysis: Object Model I formatio comes from The prob em stateme t a d use cases Expert k o edge of the app icatio domai oi tervie s ith customer oco su tatio ith experts ooutside research performed by a a yst Ge era k o edge of the rea or d

83 Object Model: Steps to follow Ide tify c asses a d associatio s ou s a d verbs i a prob em descriptio Create data dictio ary e try for each Add attributes Combi e a d orga ize c asses usi g i herita ce

84 Analysis: Dynamic model Sho s the time depe de t behavior of the system a d the objects i it Expressed i terms of states of objects a d activities i states eve ts a d actio s State diagram summarizes permissib e eve t seque ces for objects ith importa t dy amic behavior

85 Dynamic Model: Steps to follow Use cases provide sce arios of typica i teractio seque ces Ide tify eve ts bet ee objects (Seque ce Diagram) Prepare a eve t trace for each sce ario Bui d state diagrams Match eve ts bet ee objects to verify co siste cy

86 Analysis: Iteration A a ysis mode i require mu tip e passes to comp ete Look for i co siste cies a d revise Look for omissio s/vague ess a d revise Va idate the fi a mode ith the customer