Software Modeling and Analysis (CS 284) PDF

Software Modeling and Analysis (CS 284) CS 211 College of Science and Computer Engineering...

Software Modeling and Analysis (CS 284) CS 211 College of Science and Computer Engineering Taibah University Yanbu Saudi Arabian First Semester 1443 2021-2022 Dr. Musab Kasim Alqudah Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 1 Object-Oriented Software Engineering Using UML, Patterns, and Java Chapter 2, Modeling with UML Application and Solution Domain  Application Domain (Requirements Analysis):  The environment in which the system is operating  Solution Domain (System Design, Object Design):  The available technologies to build the system Application Domain Solution Domain Application Domain Model System Model UML Package TrafficControl SummaryDisplay MapDisplay TrafficController FlightPlanDatabase Aircraft FlightPlan Airport TrafficControl Is the “system” part of the Domain or (part of) the Solution? Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 3 What is UML?  UML (Unified Modeling Language)  An emerging standard for modeling object-oriented software.  Resulted from the convergence of notations from three leading object-oriented methods:  OMT (James Rumbaugh)  OOSE (Ivar Jacobson)  Booch (Grady Booch)  Reference: “The Unified Modeling Language User Guide”, Addison Wesley, 1999.  Supported by several CASE tools  Rational ROSE  TogetherJ Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 4 UML: First Pass  You can model 80% of most problems by using about 20 % UML  We teach you those 20%  Use case Diagrams What system?  Describe the functional behavior of the system as seen by the user.  Class diagrams Are class diagrams of this sort about requirements or design?  Describe the static structure of the system: Objects, Attributes, Associations  Sequence diagrams Are sequence diagrams of this sort about requirements or design?  Describe the dynamic behavior between actors and the system and between objects of the system  Statechart diagrams Are StateCharts of this sort about requirements or design?  Describe the dynamic behavior of an individual object (essentially a finite state automaton)  Activity Diagrams Are activity diagrams of this sort about requirements or design?  Model the dynamic behavior of a system, in particular the workflow (essentially a flowchart) Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 5 Collaboration, Object, Component, Deployment diagrams in UML 1.x UML Core Conventions  Rectangles are classes or instances  Ovals are functions or use cases states  Instances are denoted with an underlined names  myWatch:SimpleWatch  Joe:Firefighter  Types are denoted with non underlined names  SimpleWatch  Firefighter  Diagrams are graphs  Nodes are entities  Arcs are relationships between entities Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 6 Use Case Diagrams  Used during requirements elicitation to represent external behavior  Actors represent roles, that is, a type of user of the system Passenger  Use cases represent a sequence of interaction for a type of functionality  The use case model is the set of all use cases. It is a complete description of the functionality of PurchaseTicket the system and its environment What would the functionality of the environment mean? Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 7 Actors  An actor models an external entity which communicates with the system:  User  External system  Physical environment  An actor has a unique name and an optional Passenger description.  Examples:  Passenger: A person in the train  GPS satellite: Provides the system with GPS coordinates course project? Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 8  Use Case A use case represents a class of functionality provided by the system as an event flow. A use case consists of: PurchaseTicket  Unique name  Participating actors  Entry conditions  Flow of events  Exit conditions  Special requirements Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 9 Use Case Diagram: Example Name: Purchase ticket Event flow: 1. Passenger selects the number of Participating actor: Passenger zones to be traveled. 2. Distributor displays the amount due. Entry condition: 3. Passenger inserts money, of at  Passenger standing in front of least the amount due. ticket distributor. 4. Distributor returns change.  Passenger has sufficient money to purchase ticket. 5. Distributor issues ticket. Exit condition:  Passenger has ticket.  Use case diagrams represent external behavior  Use case descriptions provide meat of model, not the use case diagrams.  All use cases need to be described for the model to be useful. Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 10  Class Diagrams = OO? TarifSchedule Trip Enumeration getZones() zone:Zone Price getPrice(Zone) * * Price: Price  Class diagrams represent the structure of the system.  Used  during requirements analysis to model problem domain concepts  during system design to model subsystems and interfaces  during object design to model classes. Is this from user’s point of view? Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 11 Classes TarifSchedule Table zone2price Enumeration getZones() Name Price getPrice(Zone) TarifSchedule zone2price Attributes Signature getZones() getPrice() Operations TarifSchedule  A class represent a concept  A class encapsulates state (attributes) and behavior (operations).  Each attribute has a type.  Each operation has a signature.  The class name is the only mandatory information. Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 12 Instances tarif_1974:TarifSchedule zone2price = { {‘1’,.20}, {‘2’,.40}, {‘3’,.60}}  An instance represents a phenomenon.  The name of an instance is underlined and can contain the class of the instance.  The attributes are represented with their values. Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 13 Actor vs Instances  What is the difference between an actor , a class and an instance?  Actor:  An entity outside the system to be modeled, interacting with the system (“Passenger”)  Class:  An abstraction modeling an entity in the problem domain, must be modeled inside the system (“User”) Would you agree?  Object:  A specific instance of a class (“Joe, the passenger who is purchasing a ticket from the ticket distributor”). Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 14 Associations TarifSchedule TripLeg Enumeration getZones() Price Price getPrice(Zone) * * Zone  Associations denote relationships between classes.  The multiplicity of an association end denotes how many objects the source object can legitimately reference. Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 15  1-to-1, 1-to-many, many-to-many Associations Point Country Has-capital City Polygon name:String * name:String * x: Integer y: Integer draw() One-to-one association One-to-many association Company StockExchange Lists * * tickerSymbol StockExchange * Lists 1 Company tickerSymbol SX_ID Bernd Bruegge & Allen H. Dutoit Many-to-Many Associations Object-Oriented Software Engineering: Using UML, Patterns, and Java 16  Aggregation  An aggregation is a special case of association denoting a “consists of” hierarchy.  The aggregate is the parent class, the components are the children class. Exhaust system Exhaust system 1 0..2 1 0..2 Muffler Tailpipe Muffler Tailpipe diameter diameter diameter diameter  A solid diamond denotes composition, a strong form of aggregation where components cannot exist without the aggregate. (Bill of Material) TicketMachine 3 ZoneButton Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 17 Inheritance Button CancelButton ZoneButton  The children classes inherit the attributes and operations of the parent class. What else?  Inheritance simplifies the model by eliminating redundancy. Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 18  Object Modeling in Practice: Class Identification Class Identification: Name of Class, Attributes and Methods Foo Betrag CustomerId “Dada” Foo Deposit() Withdraw() Betrag Betrag GetBalance() CustomerId CustomerId Deposit() Deposit() Withdraw() Withdraw() GetBalance() GetBalance() Account Betrag CustomerId Naming is important! Deposit() Is Foo the right name? Withdraw() GetBalance() Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 19 Object Modeling in Practice ctd Account Betrag Customer Bank AccountId CustomerId Name Name Deposit() CustomerId Withdraw() GetBalance() 1) Find New Objects 2) Iterate on Names, Attributes and Methods Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 20 Object Modeling in Practice: A Banking System Account Betrag Customer Bank AccountId CustomerId AccountId * Has Name Name Deposit() CustomerId Withdraw() GetBalance() 1) Find New Objects 2) Iterate on Names, Attributes and Methods 3) Find Associations between Objects 4) Label the assocations 5) Determine the multiplicity of the assocations Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 21 Practice Object Modeling: Iterate, Categorize! Account Bank Customer Name * Amount * Has Name AccountId CustomerId AccountId Deposit() What should these do? Withdraw() GetBalance() CustomerId() Savings Checking Mortgage Account Account Account Withdraw() Withdraw() Withdraw() Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 22 Packages  A package is a UML mechanism for organizing elements into groups (usually not an application domain concept)  Packages are the basic grouping construct with which you may organize UML models to increase their readability. DispatcherInterface Notification IncidentManagement  A complex system can be decomposed into subsystems, where each subsystem is modeled as a package Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 23 UML sequence diagrams  Used during requirements analysis  To refine use case descriptions TicketMachine  to find additional objects (“participating Passenger objects”) selectZone()  Used during system design  to refine subsystem interfaces  Classes are represented by columns  Messages are represented by arrows  Activations are represented by narrow insertCoins() rectangles  Lifelines are represented by dashed lines pickupChange() pickUpTicket()  UML sequence diagram represent behavior in terms of interactions.  Useful to find missing objects.  Time consuming to build but worth the investment.  Complement the class diagrams (which represent structure). Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 24  Nested messages ZoneButton TarifSchedule Display Passenger selectZone() lookupPrice(selection) price displayPrice(price) Dataflow …to be continued...  The source of an arrow indicates the activation which sent the message  An activation is as long as all nested activations  Horizontal dashed arrows indicate data flow  Vertical dashed lines indicate lifelines Is this from user’s point of view? Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 25  Iteration & condition …continued from previous slide... ChangeProcessor CoinIdentifier Display CoinDrop Passenger *insertChange(coin) lookupCoin(coin) price Iteration displayPrice(owedAmount) [owedAmount 40M lines of code  A single programmer cannot manage this amount of code in its entirety.  Code is not easily understandable by developers who did not write it  We need simpler representations for complex systems  Modeling is a means for dealing with complexity Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 37  Self-reading Example: street map 1. Abstraction 2. Decomposition 3. Hierarchy Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 38  Self-reading Systems, Models and Views  A model is an abstraction describing a subset of a system  A view depicts selected aspects of a model  A notation is a set of graphical or textual rules for depicting views  Views and models of a single system may overlap each other Examples:  System: Aircraft  Models: Flight simulator, scale model  Views: All blueprints, electrical wiring, fuel system Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 39  Self-reading Systems, Models and Views Flightsimulator Blueprints Aircraft Model 2 View 2 View 1 System View 3 Model 1 Electrical Wiring Scale Model Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 40  Self-reading Models, Views and Systems (UML) * * System Model View Described by Depicted by What does this rectangle mean? Airplane: System Scale Model: Model Flight Simulator: Model Blueprints: View Fuel System: View Electrical Wiring: View Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 41  Self-reading Concepts and Phenomena Phenomenon  An object in the world of a domain as you perceive it  Example: The lecture you are attending  Example: My black watch Concept  Describes the properties of phenomena that are common.  Example: Lectures on software engineering  Example: Black watches Concept is a 3-tuple: loose  Name (To distinguish it from other concepts)  Purpose (Properties that determine if a phenomenon is a member of a concept)  Members (The set of phenomena which are part of the concept) Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 42  Self-reading Concepts and phenomena Name Purpose Members Clock A device that measures time.  Abstraction  Classification of phenomena into concepts  Modeling  Development of abstractions to answer specific questions about a set of phenomena while ignoring irrelevant details. Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 43 Models for Plato’s and Aristotle’s Views of Reality Plato Aristotle  Material reality is a second-class Aristotle accepted the reality of Forms as  subordinate type of reality. nonmaterial entities.  The first-class type is a “form”  However, he could not accept Plato’s idea, Forms lie behind every thing or in that these Forms were not real. the world. Forms can be abstract nouns like “beauty” or “mammal”  Instead of two separate worlds, one for or concrete nouns like “tree” or Forms and one for Particulars, Aristotle “horse”. had only one world, a world of particular things.  There is an important difference between the world of forms and  Particular things according to Aristotle particulars. Forms are nonmaterial, have a certain permance about them, even particulars are material. Forms are while they are subject to change: A tree permanent and changeless. changes colors without ceasing to be a Particulars are changing. tree. A horse grows in size without ceasing to be a horse.  Forms can be acquired intellectually through a “dialectic”  What is the root of this permancence? It is process that moves toward the the thing’s internal form, which minds highest understanding of reality detect, when they penetrate beyond the through the interaction of questions thing’s changing attributes. So for and answers. Aristotle, reality is thus made up of particularviewpoints Using UML, we can illustrate Platon’s and Aristotle’s things that are each very composed of easily form antdn matter.. and see their differences as well Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 44 Model for Plato’s View of Reality Plato  Material reality is a second- class subordinate type of reality. Reality  The first-class type is a “form” Forms lie behind every thing or in the world. Forms can be abstract nouns like “beauty” or “mammal” or concrete nouns like “tree” or “horse”. *  There is an important difference Thing between the world of forms and particulars. Forms are nonmaterial, particulars are material. Forms are permanent and changeless. Particulars are changing.  Forms can be acquired Particular Form intellectually through a “dialectic” process that moves toward the highest understanding of reality Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 45 Model Aristotle’s Views of Reality Aristotle  Aristotle accepted the reality of Forms as nonmaterial entities.  However, he could not accept Plato’s idea, that these Forms were Reality not real.  Instead of two separate worlds, one for Forms and one for Particulars, Aristotle had only one world, a world of particular things.  Particular things according to * Aristotle have a certain permance Substance about them, even while they are subject to change: A tree changes colors without ceasing to be a tree. A horse grows in size without ceasing to be a horse.  What is the root of this Form Matter permancence? It is the thing’s internal form, which minds detect, when they penetrate beyond the thing’s changing attributes. So for Aristotle, reality is thus made up of particular Bernd Bruegge & things that are each Object-Oriented Software Engineering: Using UML, Patterns, and Java Allen H. Dutoit 46 composed of form antdn matter.. Comparison of Plato’s and Aristotle’s Views Plato Aristotle Reality Reality * * Thing Substance Form Matter Particular Form Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 47  The Relationship  relationships represent exceptional or seldom invoked cases.  The exceptional event flows are Passenger factored out of the main event flow for clarity.  Use cases representing exceptional flows can extend more than one PurchaseTicket use case.  The direction of a relationship is to the extended use case OutOfOrder TimeOut Cancel NoChange Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 48  The Relationship  relationship represents behavior that is factored Passenger out of the use case.  behavior is factored out for reuse, not because PurchaseMultiCard it is an exception. PurchaseSingleTicket  The direction of a relationship is to the using use case (unlike relationships). CollectMoney NoChange Cancel Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 49 Concepts in software: Type and Instance  Type:  An abstraction in the context of programming languages  Name: int, Purpose: integral number, Members: 0, -1, 1, 2, -2,...  Instance:  Member of a specific type  The type of a variable represents all possible instances the variable can take The following relationships are similar:  “type” “instance”  “concept” “phenomenon” Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 50 Abstract Data Types & Classes  Abstract data type  Special type whose implementation is hidden Watch from the rest of the system. time  Class: date  An abstraction in the context of object- oriented languages SetDate(d)  Like an abstract data type, a class encapsulates both state (variables) and behavior (methods)  Class Vector CalculatorWatch  Unlike abstract data types, classes can be calculatorState defined in terms of other classes using EnterCalcMode() inheritance InputNumber(n) Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 51  From Problem Statement To Object Model Is this a “problem”? Problem Statement: A stock exchange lists many companies. Each company is uniquely identified by a ticker symbol Class Diagram: StockExchange * * Company Lists tickerSymbol problem statement = requirement? = domain description? Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 52 From Problem Statement to Code Is this a “problem”? Problem Statement : A stock exchange lists many companies. Each company is identified by a ticker Symbol Class Diagram: StockExchange * * Company Lists tickerSymbol Java Code public class StockExchange { private Vector m_Company = new Vector(); Where is the design, then? }; public class Company { public int m_tickerSymbol; private Vector m_StockExchange = new Vector(); }; Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 53 Qualifiers Without qualification 1 * File Directory filename With qualification 1 0…1 Directory filename File  Qualifiers can be used to reduce the multiplicity of an association. Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 54 UML first pass: Use case diagrams Package Use case Watch Actor ReadTime SetTime WatchUser WatchRepairPerson ChangeBattery Use case diagrams represent the functionality of the system from user’s point of view Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 55  UML first pass: Class diagrams Class diagrams represent the structure of the system Association Class Multiplicity Watch 1 1 1 1 2 1 2 1 PushButton LCDDisplay Battery Time state blinkIdx load now push() blinkSeconds() release() blinkMinutes() blinkHours() stopBlinking() referesh() Attribute Operations Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 56  UML first pass: Sequence diagram Actor Object :Watch :LCDDisplay :Time :WatchUser pressButton1() blinkHours() pressButton1() blinkMinutes() Message pressButton2() incrementMinutes() refresh() pressButtons1And2() commitNewTime() stopBlinking() Activation Lifeline Sequence diagrams represent the behavior as interactions Is this from user’s point of view? Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 57  UML first pass: Statechart diagrams for objects with interesting dynamic behavior Event State Initial state [button2Pressed] [button1&2Pressed] BlinkHours IncrementHrs [button1Pressed] Transition [button1&2Pressed] [button2Pressed] BlinkMinutes IncrementMin. [button1Pressed] [button1&2Pressed] [button2Pressed] BlinkSeconds IncrementSec. StopBlinking Final state Represent behavior as states and transitions Is this from user’s point of view? Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 58 Other UML Notations UML provide other notations that we will be introduced in subsequent lectures, as needed.  Implementation diagrams  Component diagrams  Deployment diagrams  Introduced in lecture on System Design  Object constraint language  Introduced in lecture on Object Design These are from UML 1.x Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 59 What should be done first? Coding or Modeling?  It all depends….  Forward Engineering:  Creation of code from a model  Greenfield projects  Reverse Engineering:  Creation of a model from code  Interface or reengineering projects  Roundtrip Engineering:  Move constantly between forward and reverse engineering  Useful when requirements, technology and schedule are changing frequently Bernd Bruegge & Allen H. Dutoit Object-Oriented Software Engineering: Using UML, Patterns, and Java 60