Week 1

The Analyst as a Business Problem Solver Analyst background: computer technology, object-oriented analysis and design, curiosity   Chief task: define problem and outline solution Challenge: develop alternatives consistent with corporate strategic Develop system requirements and design models Systems design models: databases, user interfaces, networks, operating procedures, conversion plans, and, software classes Object-Oriented Analysis and Design with the Unified Process

Figure 1-1 The Analyst’s Approach to Problem Solving Fig 1-1A Fig 1-1B Object-Oriented Analysis and Design with the Unified Process

Information Systems Information system: collects, processes, stores, and outputs information Subsystem: components of another system Components: hardware, software, inputs, outputs, data, people, and procedures Supersystem: collection of systems Automation boundary: separates automated part of system from manual (human) Object-Oriented Analysis and Design with the Unified Process

Information Systems and Component Parts Figure 1-3 Information Systems and Component Parts Object-Oriented Analysis and Design with the Unified Process

Types of Information Systems There are many types of information systems Six common systems are found in most businesses Business systems center around transactions Systems must adapt to changing technology Object-Oriented Analysis and Design with the Unified Process

Types of Information Systems Figure 1-5 Types of Information Systems Object-Oriented Analysis and Design with the Unified Process

Required Skills of the Systems Analyst Analysts manage issues ranging from technical to interpersonal Analyst must commit to lifelong learning Object-Oriented Analysis and Design with the Unified Process

Required Skills of the Systems Analyst Figure 1-6 Required Skills of the Systems Analyst Object-Oriented Analysis and Design with the Unified Process

Technical Knowledge and Skills Analysts should grasp many types of technology Analysts should be informed of tools and techniques Common software tools: IDEs and CASE Common techniques Project planning Cost-benefit analysis Architectural Analysis Object-Oriented Analysis and Design with the Unified Process

Business Knowledge and Skills Analysts should understand organizational structure Analysts should understand business concern Many analysts formally study business administration CIS and MIS majors often included in business colleges Object-Oriented Analysis and Design with the Unified Process

People Knowledge and Skills Knowledge of people centers around thinking and feeling People knowledge used to adapt systems to users Most critical skill: ability to listen empathetically Object-Oriented Analysis and Design with the Unified Process

The Environment Surrounding the Analyst Occupational environment is not fixed Analysts will encounter many types of technology Analysts will work in many locations Analysts are assigned a variety of job titles Object-Oriented Analysis and Design with the Unified Process

Types of Technology Wide range: from desktops to large scale information systems Variety of computers connected by complex networks Technology change is continuous Innovation often drives information system change Regular upgrades of knowledge and skills essential Object-Oriented Analysis and Design with the Unified Process

A Few Words about Integrity and Ethics Sense of personal integrity and ethics essential Analysts often encounter personal information Analysts encounter confidential proprietary information Keep confidential and sensitive information private Improprieties can ruin an analyst’s career Object-Oriented Analysis and Design with the Unified Process

The Traditional Predictive SDLC Approaches Five activities or phases in a project Planning, analysis, design, implementation, support Pure waterfall approach (predictive SDLC) Assumes project phases can be sequentially executed Project drops over the “waterfall” into the next phase Modified waterfall approach Tempers pure waterfall by recognizing phase overlap Informs many current projects and company systems Object-Oriented Analysis and Design with the Unified Process

SDLC Phases and Objectives Figure 2-3 SDLC Phases and Objectives Object-Oriented Analysis and Design with the Unified Process

The Waterfall Approach to the SDLC Figure 2-4 The Waterfall Approach to the SDLC Object-Oriented Analysis and Design with the Unified Process

The Newer Adaptive Approaches to the SDLC The spiral model: early form of adaptive SDLC Activities radiate from center starting point Prototypes are artifacts of each phase Iterative problem solving: repeats activities Several approaches to structuring iterations Define and implement the key system functions Focus on one subsystem at a time Define by complexity or risk of certain components Complete parts incrementally Object-Oriented Analysis and Design with the Unified Process

The Spiral Life Cycle Model Figure 2-6 The Spiral Life Cycle Model Object-Oriented Analysis and Design with the Unified Process

The Unified Process Life Cycle UP life cycle Includes (4) phases which consist of iterations Iterations are “mini-projects” Inception: develop and refine system vision Elaboration: define requirements and core architecture Construction: continue design and implementation Transition: move the system into operational mode Object-Oriented Analysis and Design with the Unified Process

Unified Process Object-Oriented Analysis and Design with the Unified Process

The Unified Process System Development Life Cycle Figure 2-8 The Unified Process System Development Life Cycle Object-Oriented Analysis and Design with the Unified Process

UP Phases and Objectives Figure 2-9 UP Phases and Objectives Object-Oriented Analysis and Design with the Unified Process

Methodologies and System Development Processes System development methodology Provides guidelines every activity in system development Includes specific models, tools, and techniques UP is a system development methodology Process is a synonym for methodology Methodologies supported with documentation Object-Oriented Analysis and Design with the Unified Process

Models Model abstract (separate) aspects of the real world Models come in many forms Physical analogs, mathematical, graphical System development models are highly abstract Depict inputs, outputs, processes, data, objects, interactions, locations, networks, and devices Unified Modeling Language (UML): standard notation PERT or Gantt charts: model project itself Object-Oriented Analysis and Design with the Unified Process

Some Models used in System Development Figure 2-10 Some Models used in System Development Object-Oriented Analysis and Design with the Unified Process

Tools Tool: software used to create models or components Example tools Project management software tools (Microsoft Project) Integrated development environments (IDEs) Code generators Computer-aided system engineering (CASE) Object-Oriented Analysis and Design with the Unified Process

Techniques Technique Example techniques Collection of guidelines Enables an analyst to complete an activity or task Example techniques Domain-modeling , use case modeling, software-testing, user-interviewing techniques, relational database design techniques Proven techniques are embraced as “Best Practices” Object-Oriented Analysis and Design with the Unified Process

Figure 2-13 Relationships of Models, Tools, and Techniques in a System Development Methodology Object-Oriented Analysis and Design with the Unified Process

The Unified Process as a System Development Methodology UP: object-oriented system development methodology UP should be tailored to organizational and project needs Project will be use case driven Object-Oriented Analysis and Design with the Unified Process

The Unified Process as a System Development Methodology (continued) Use case Activity that the system carries out Basis for defining requirements and designs UP defines disciplines within each phase Discipline: set of functionally related activities Iterations concatenate activities from all disciplines Activities in each discipline produce artifacts; models, documents, source code, and executables Object-Oriented Analysis and Design with the Unified Process

UP Life Cycle with Phases, Iterations, and Disciplines Figure 2-15 UP Life Cycle with Phases, Iterations, and Disciplines Object-Oriented Analysis and Design with the Unified Process

The UP Disciplines Six main UP development disciplines Each iteration Business modeling, requirements, design, implementation, testing, and deployment Each iteration Similar to a mini-project Results in a completed portion of the system Three additional support disciplines Project management, configuration and change management, and environment Object-Oriented Analysis and Design with the Unified Process

Business Modeling Purpose: understand business environment Three major activities part of business modeling Understand surroundings Create the system vision Create business models Object-Oriented Analysis and Design with the Unified Process

Requirements Objective: document business requirements Key drivers of activities: discovery and understanding Requirements discipline and business modeling map to traditional systems analysis Activities list Gather detailed information Define functional and nonfunctional requirements Develop user interface dialogs Evaluate requirements with users Object-Oriented Analysis and Design with the Unified Process

Design Objective: design system based on requirements Six major activities in the design discipline Design support services architecture and deployment environment Design the software architecture Design use case realizations Design the database Design the system and user interfaces Design the system security and controls Object-Oriented Analysis and Design with the Unified Process

Implementation Objective: build or acquire needed system components Implementation activities Build software components Acquire software components Integrate software components Object-Oriented Analysis and Design with the Unified Process

Testing Testing is critical discipline Testing activities Define and conduct unit testing Define and conduct integration testing Define and conduct usability testing Define and conduct user acceptance testing In UP, acceptance testing occurs throughout the building phase Object-Oriented Analysis and Design with the Unified Process

Deployment Goal: conduct activities to make system operational Deployment activities Acquire hardware and system software Package and install components Train users Convert and initialize data Deployment activities prominent in transition phase Object-Oriented Analysis and Design with the Unified Process

Project Management Most important support discipline Project management activities Finalize the system and project scope Develop the project and iteration schedule Identify project risks and confirm feasibility Monitor and control the project’s plan Monitor and control communications Monitor and control risks and outstanding issues Object-Oriented Analysis and Design with the Unified Process

Configuration and Change Management Configuration and change discipline pertains to: Requirements Design Source code Executables The two activities in this discipline Develop change control procedures Manage models and software components Object-Oriented Analysis and Design with the Unified Process

Environment Development environment includes Available facilities Design of the workspace Forums for team communication and interaction Environment discipline activities Select and configure the development tools Tailor the UP development process Provide technical support services Object-Oriented Analysis and Design with the Unified Process

Overview of Object-Oriented Concepts OOA views system as a collection of objects Object: entity capable of responding to messages Languages: Simula, C++, Java, C#, Visual Basic .NET Object-oriented design (OOD) Defines additional types of communication objects Shows how the objects interact to complete tasks Refines definition of objects for implementation Object-oriented programming (OOP): object coding Object-Oriented Analysis and Design with the Unified Process

Characteristics of Object-Oriented Systems Classes and Objects – A class is a template used to define and create objects. Every object is associated with a class. An object has attributes that describe the information about the object. Each object has behaviors that specify what the object can do. Methods and Messages – Methods implement an object’s behavior. A method is nothing more than an action that an object can perform. Messages are information sent to objects to trigger methods. Basically, a message is a function or procedure call from one object to another object. Object-Oriented Analysis and Design with the Unified Process

Encapsulation and Information Hiding – The ideas of encapsulation and information hiding are interrelated in OO systems. Encapsulation is the combination of process and data into a single entity. Information hiding suggests that only the information required to use a software module be published to the user of the module. Exactly how the module implements the required functionality is not relevant. Inheritance – This is used to identify higher-level or more general classes of objects. Common sets of attributes and methods can be organized into superclasses or parent classes. The relationship between the class and its superclass is known as a “Is A” relationship. For example, a heart surgeon “Is A” doctor. Subclasses or child classes inherit appropriate attributes and methods from the superclass above them in the class hierarchy. Object-Oriented Analysis and Design with the Unified Process

Polymorphism and Dynamic Binding – Polymorphism means that the same message can be interpreted differently by different classes of objects. Because we are not concerned with “how” something is done, we can simply send a message to an object and that object will be responsible for interpreting the message appropriately. Polymorphism is made possible through dynamic binding. Dynamic, or late binding, is a technique that delays typing the object until run-time. As such, the specific method that is actually being called is not chosen by the OO system until the system is running. This is in contrast to static binding where the object type is determined at compile time. Object-Oriented Analysis and Design with the Unified Process

Recognizing the Benefits of OO Development Original application of object-oriented technology Computer simulations Graphical user interfaces Rationale for use in information systems Benefits of naturalness Reusability   Object-Oriented Analysis and Design with the Unified Process

Objects Are More Natural OO approach mirrors human perception: objects moving through space OOA, OOD, and OOP imitate perceptual processes by modeling classes of objects Some system developers resist OO development New programmers are more receptive to OO approach System users appreciate object-orientation They discuss the objects involved in their work Hierarchies are common tools for organizing knowledge Object-Oriented Analysis and Design with the Unified Process

Classes of Objects Can Be Reused Classes of objects have a long shelf life Example: Customer class adaptability Reused in systems where customer objects needed Extended through inheritance to a new subclass Reused during analysis, design, or programming Classes may be stored, with implementation hidden, in class libraries Object-Oriented Analysis and Design with the Unified Process

Understanding Object-Oriented Concepts Object: thing with attributes and behaviors Types of objects User interface Problem domain objects Attributes are associated with data Behaviors are associated with methods, functions, and procedures Object-Oriented Analysis and Design with the Unified Process

Attributes and Methods in Problem Domain Objects Figure 2-18 Attributes and Methods in Problem Domain Objects Object-Oriented Analysis and Design with the Unified Process

Understanding Object-Oriented Concepts (continued) Class: defines what all objects of class represent Objects are instances of a class Customer object is an instance of a customer class Objects interact through messages Objects retain memory of transactions Object-Oriented Analysis and Design with the Unified Process

Order-processing system where objects interact by sending messages Figure 2-20 Order-processing system where objects interact by sending messages Object-Oriented Analysis and Design with the Unified Process

Understanding Object-Oriented Concepts (continued) Objects maintain association relationships Encapsulation: combining attributes and methods into one unit Information hiding: separating specification from implementation Inheritance: extending the characteristics of a class Polymorphism: ability for dissimilar objects to respond to the same message Object-Oriented Analysis and Design with the Unified Process

Superclasses and Subclasses Figure 2-22 Superclasses and Subclasses Object-Oriented Analysis and Design with the Unified Process

Tools to Support System Development CASE (Computer Aided System Engineering) Database repository for information system Set of tools that help analysts complete activities Sample artifacts: models, automatically generated code Variations on CASE Visual modeling tools Integrated application development tools Round-trip engineering tools Object-Oriented Analysis and Design with the Unified Process

A Case Tool Repository Contains All Information About the System Figure 2-24 A Case Tool Repository Contains All Information About the System Object-Oriented Analysis and Design with the Unified Process

Tools to Support System Development (continued) Microsoft Visio: emphasizes technical drawing Rational Rose CASE tool supporting object-oriented approach Strongly identified with  UP methodology Together Pioneers round-trip engineering synchronizes graphical models with generated program code Leverages UML diagrams Object-Oriented Analysis and Design with the Unified Process

Object-Oriented Analysis and Design with the Unified Process

Object-Oriented Analysis and Design with the Unified Process

Object-Oriented Analysis and Design with the Unified Process

Object-Oriented Analysis and Design with the Unified Process

Actor Generalization Actor generalization factors out behavior common to two or more actors into a parent actor. In order to determine if you have a situation that can use actor generalization, look for a high degree of commonality between actors. Do two actors communicate with the same set of use cases in the same way? If there is, you can factor out common actor behavior into a more generalized actor. You will have a parent actor and one or more descendent actors. The descendant actors inherit the roles and relationships to use cases held by the parent actor. You can substitute a descendent actor anywhere the parent actor is expected. Object-Oriented Analysis and Design with the Unified Process

Actor Generalization Object-Oriented Analysis and Design with the Unified Process

Use-Case Generalization Use-case generalization factors out behavior common to one or more use cases into a parent use case. It is used when you have one or more use cases that are really specializations of a more general use case. The child use cases represent more specific forms of the parent. The children may: inherit features from their parent use case; add new features; override (change) inherited features. Object-Oriented Analysis and Design with the Unified Process

Use-Case Generalization Object-Oriented Analysis and Design with the Unified Process