keybd INPUT yes screen OUTPUT lf ~\n 1 nolist fmt \n\N\n\T\n yes UseCase 1 yes general 2 degrees AddOns >StateDiagrams >ProcessDiagrams >InteractionDiagram AnalysisModel Go through use cases, abstracting all of the objects neded to satisfy the requirements, and the relationships between them. Interface objects define interfaces to actors. Entity objects model problem domain objects. Use one control objet per use case. AnAnalysisAndDesignPlan This plan combines elements of Jacobson's requirements analysis, with Booch's design descriptions. See >BasicPlan for a description of the basic elements of an analysis and design plan. See >AddOns for a list of tools that could be used as needed. See >PlanDeliverables for a summary of the deliverable items in the plan. See >PlanBenefits for benificial features of the plan. See >PlanDrawbacks for the downside. ApproachesToAnalysisAndDesign "Older Approaches" >Unstructured >Hatley_Pirbhai >Ward_Mellor "Newer Approaches" >Booch >Schlaer_Mellor >Jacobsen >CoadYourdon >Yourdon >WaldenNerson BasicPlan Analysis >UseCases -- give example >UserAndCommInterfaces >ObjectModel >AnalysisModel -- example Design >ClassOverview --example >ClassDefinitionAndInterfaces -- static view -- ex. >ObjectInteractionScenarios -- dynamic views --ex. Booch Strong on design. Surveys existing techniques for identifying objects and classes. ClassDefinitionAndInterfaces Detailed definitions of each class, including: detailed descriptions of encapsulated data elements, data types of encapsulated data, argument and return types of methods, detailed description of methods, suitable for coding. ClassesAndObjects Object -- A run time program unit that has state, behavior, and identity. State is a description of the values of data encapsulated by the object. Behavior is the collection of methods which access and/or change the state of the object. Identity is what distinguishes one object from another. An object is capable of receiving and acting upon messages from each of its methods. Class -- A specification in a programming language of the permissable states and behavior of one or more objects. We can think of the class as the means of defining and abstract data type, with its accessing functions and encapsulated data, and an object as an instance variable of the class. ClassOverview A textual or graphical overview of the classes necessary to implement a solution to the requirements, including: Class names Brief description of class purpose Attribute, or data names Service or method names Connections to other classes, including: associations & using relationships inheritance relationships generalization relationships CoadSays Look for structures, other systems, devices, things or events remembered, roles played, operational procedures, sites, organizational units. Consider and Challange classes and objects based on following criteria: needed rememberance needed behavior (usually) multiple attributes (usually) more than one object in a class always applicable attributes domain-based requirements not merely derived results CoadYourdon Simplified Booch. Has what has become a fairly standard class symbol. We tried the approach, and it is not rich enough in diagramming for real time work. CRCCards 3x5 card with class name, class responsibilities, and collaborators. Deliverables The deliverables can be constructed with CASE tools from Rational Software; or they may be produced with text and diagram editors, or with text and hypertext editors, according to the preference of the designer. DomainAnalysis Model the problem domain, identify classes and objects that are common to all applications. GoalOfSeminar Pique Interest in OOAD among developers. Illustrate a sample process. Supply references for further study. GoalsOfAnalysisAndDesign For our purposes, the goals of analysis and design are: 1) To create a specification of interacting software >ClassesAndObjects which utilize the target hardware to solve the problems posed by the product requirements. 2) To demonstrate that the design satisfies the product requirements, and mitigates the hazards forseen. 3) To communicate to developers the theory of operation of the software system designed. Hatley_Pirbhai Data and Control Flow, and State diagrams. home OOAD stands for Object Oriented Analysis and Design. This web outlines a seminar I will give on an improved software analysis and design process. >GoalOfSeminar >WhatIsAnalysisAndDesign >WhatIsItsStartingPoint >GoalsOfAnalysisAndDesign >ApproachesToAnalysisAndDesign >AnAnalysisAndDesignPlan >Presentation InformalTextualDescription Underline nows and verbs to get objexts, attributes and services. InteractionDiagram Traces the execution of an object scenario. Jacobson Requirements Analysis is strongest feature, especially use case analysis as preliminary for identifying objects and interactions implied by requirements. ObjectInteractionScenarios These are graphical or textual descriptions of how the methods work together to accomplish the main use cases in the system. ObjectModel How to identify the problem domain objects: >CRCCards >InformalTextualDescription Identify objects in use cases >DomainAnalysis >CoadSays PlanBenefits Specific benefits of process are: 1) The use cases not only facilitate analysis, they are also input to the validation plan, and can be used to verify the design, as well as the finished product. 2) Compilation of the use cases overlaps with the user interface work. Now the user interface work can serve multiple purposes...define the interface, and drive analysis. 3) Requirements model work blends into design work without discontinuity, as in some methods. 4) Flexibility of required deliverables augmented as needed by addons. PlanDeliverables Analysis UseCases --text descriptions >UserAndCommInterfaces >ObjectModel AnalysisModel -- graphical or text descr. Design ClassOverview --diagram or text ClassDefinitionAndInterfaces -- diagram or text ObjectInteractionScenarios -- diagram or descr. State transitions, process descriptions, and interaction diagrams as needed. PlanDrawbacks Use case analysis can get quite complicated and time consuming. Bill part of overhead to V&V, since it is input to the validation plan. Use CASE tool or database for repository. It may take longer to arrive at the appropriate set of abstractions than it would with a top down, structured analysis. On the other hand the abstractions are likely to be more robust. Presentation Present each piece of the plan, and illustrate it with examples as you go. ProcessDiagrams A simple flow chart of the main loop of all the processes employed by the system. ProposedMethodology Analysis begins with >UseCase, generates a >RequirementsObjectModel. UseCase database used to create validation plan, and do user interface work. In the design phase, develop a StaticSystemView, ObjectInteractionDiagrams or scenarios for significant interactions. Do a detailled class specification (including interfaces) Verify the design against the UseCase analysis. Schlaer_Mellor Analysis id data modeling. Design is strong on state machines. SomethingToTry StateDiagrams Describes the sequence of states through which objects go in the normal course of processing. These diagrams or hypertext descriptions would be used to describe in detail the action or interaction of methods within a class. Unstructured In unstructured Analysis and Design, you stew around in the requirements until the creative process happens. Then you start coding. UseCases Present Use Cases from Ivar's Book WaldenNerson These guys survey the OOAD literature, and then describe a software development process description called BON (Business Object Notation), which has 9 parts: DelineateSystemBorderline ListCandidateClasses SelectClassesAndGroupIntoClusters DefineClasses SketchSystemBehaviors DefinePublicFeatures RefineSystem Generalize CompleteAndReviewSystem Ward_Mellor Analysis is data and control flow. Design is Structure Charts, State Diagrams, and Data Relationship Modeling. WhatIsAnalysisAndDesign Analysis and design is that period between the time the problem is stated, and the time the solution is described. Typically, there is some kind of creative process that happens during this period. It results in an inkling of how to solve the stated problems. Analysis is the work that happens before the creative process. Design is what happens after the creative process. --------------------------------------------- According to Booch: In analysis we seek to model the world by discovering the classes and objects that form the vocabulary of the problem domain. In design, we invent the abstractions and mechanisms that provide the behavior that the model requires. WhatIsItsStartingPoint The starting point of analysis and design is the manner in which the problem is stated. Usually there is some kind of list of requirements. You might have an old system to examine. There may be discussions with users. Frequently ther is a workshop (QFD) Yourdon This is Yourdon's improvement on CoadYourdon. It is like CoadYourdon with a nod to state machines.