Introduction to Systems Analysis and Design

Information Systems Engineering! Software Engineering! Information Systems Development! Systems Engineering! Systems Analysis and Design! Other names! Which one?

An idea Analysis Design and Implementation Completed Information System SYSTEMS ANALYSIS AND DESIGN

Systems Planning Systems Planning Systems Analysis Systems Analysis Systems Design Systems Design Systems Implementation Systems Implementation Systems Evolution Systems Evolution Planning Evolution Implementation Design Analysis

Name & Address Book Name & Address Book Course Registration Course Registration Student Grades Student Grades Payroll Payroll ATM machine ATM machine Check-Out Counters Check-Out Counters Order Fulfillment Order Fulfillment Securities Portfolio Management Securities Portfolio Management Space Shuttle Flight Space Shuttle Flight Election Results Election Results Video Games (Arcade and Home) Video Games (Arcade and Home) Q-Zar Laser Tag Q-Zar Laser Tag Business problems come in all sizes and shapes. For Example:

System group of interrelated components working together to achieve a common goal group of interrelated components working together to achieve a common goal ex: transportation system, university, information system ex: transportation system, university, information system natural systems vs. man- made systems natural systems vs. man- made systems

SYSTEM boundary inputs outputs processing controls feedback Name & Address System Automobile University Inventory Management Systems Model with Six Components

Water Vehicles Cruise Ship Staterooms Suprasystem System Subsystem Systems Model Hierarchy

An AUTOMATED INFORMATION SYSTEM IS – a type of manmade system – used by one or more persons – to help them accomplish some task or assignment that they have or assignment that they have – utilizes hardware and software people procedures data software hardware

DATA - input, output, or stored DATA - input, output, or stored FUNCTIONS - transformations or actions FUNCTIONS - transformations or actions BEHAVIOR - the observable effects of a request BEHAVIOR - the observable effects of a request Characteristics of an Information System DATAFUNCTIONS BEHAVIOR

INTRODUCTION Systems Analysis and Design is the process people use to create information systems Systems Analysis and Design is the process people use to create information systems people procedures data software hardware SA&D

 SYSTEMS ANALYSIS and DESIGN produces information systems that are:  used internally within the organization  sold commercially via mail order or retail store  imbedded in products INTRODUCTION

Data vs. Information data data –raw, unprocessed facts –ex: order entry data information information –data which has been summarized, aggregated, processed into a format suitable for decision- making –sales report summarizing orders by product category and region

Information System accepts data from the environment (inputs), manipulates the data (processing) to produce information (output) accepts data from the environment (inputs), manipulates the data (processing) to produce information (output) –IPO functions include input, processing, output, storage,and control functions include input, processing, output, storage,and control

Information Systems support transaction processing support transaction processing –order entry, payroll provide information to management provide information to management –sales reports, employee skills analysis support decision-making support decision-making –marketing planning information system

Information System Components people people procedures procedures data data hardware hardware software software

Information Systems: The System Environment internal environment or organizational context internal environment or organizational context –users, management, organization structure, policies, procedures external environment external environment –customers, suppliers, governmental regulatory agencies, competitors

The Systems Approach analysis analysis –reduces a complex problem to a set of components and develops a solution for each component synthesis synthesis –integrates the solutions for individual components into a single system

Systems Development Life Cycle an engineering model which is applied to the development of information systems in business organizations an engineering model which is applied to the development of information systems in business organizations stages and tasks to be completed during the stages are identified stages and tasks to be completed during the stages are identified used as a plan for developing information systems used as a plan for developing information systems

Three Stages of the SDLC Analysis Analysis –study existing systems and identify problems or opportunities –develop system requirements –provide alternative systems as solutions Design Design –use system requirements to design system outputs, inputs, databases and files, and processes –design will be used by the developer

Three Stages of the SDLC Implementation Implementation –develop and test new system –train users and refine documentation –install and evaluate system

Analysis Problem Detection Problem Detection Initial Investigation Initial Investigation Feasibility Study Feasibility Study Prototyping Prototyping Requirements Analysis Requirements Analysis Proposal Proposal

Design Detailed Design of: Detailed Design of: –Outputs –Inputs –Files and Databases –Processes and Behaviors

Implementation –Programming and Testing (or Software Purchase) –User Training –Conversion –System Changeover –System Evaluation

Nine Activities of the SDLC systems planning systems planning feasibility study feasibility study requirements determination requirements determination conceptual design conceptual design

Nine Activities of the SDLC physical design, prototyping, construction and testing or purchase and testing, and integration physical design, prototyping, construction and testing or purchase and testing, and integration conversion conversion training training implementation implementation evolution for enhancement and maintenance evolution for enhancement and maintenance

Systems Development Catalysts user demand motivated by problems with existing systems user demand motivated by problems with existing systems –errors, efficiency, compatibility, need for system enhancements technology push technology push –new technologies motivate the development of systems to take advantage of new technologies –ex: CNA is replacing its mainframe systems with client-server systems

Systems Development Catalysts strategic pull strategic pull –new business strategies “pull” an organization into developing new systems –ex: new focus on global markets

Systems Development Goals ProjectManagementSystemQualtiy OrganizationalRelevance

System Quality functionality functionality –the system performs functions reliably, clearly, and efficiently –reliable systems are relatively error-free –clear systems have consistent and predictable functions –efficient systems execute functions with an acceptable speed

System Quality flexibility flexibility –the system is flexible and adaptive to change –the system is adaptible if components are loosely coupled –procedural flexibility is achieved when procedures are easily adapted to accommodate organizational changes –the system is portable if it can operate in a variety of environments

System Quality maintainability maintainability –the system is easily maintained if a modular design and appropriate documentation facilitate system updates and modifications

Project Management deliver a high quality system deliver a high quality system –on-time –within-budget –high level of user commitment

Organizational Relevance increase organizational efficiency increase organizational efficiency increase organizational effectiveness increase organizational effectiveness provide strategic value provide strategic value

Introduction to Systems Analysis and Design Part 2

Problems tend to have poorly defined BOUNDARIES, initially Problems tend to have poorly defined BOUNDARIES, initially Problem SOLUTIONS are artificial Problem SOLUTIONS are artificial Problems are DYNAMIC Problems are DYNAMIC Problem solutions require INTERDISCIPLINARY knowledge and skills Problem solutions require INTERDISCIPLINARY knowledge and skills Systems Analyst’s KNOWLEDGEBASE is continually expanding Systems Analyst’s KNOWLEDGEBASE is continually expanding Systems Analysis and Design is a highly COGNITIVE activity Systems Analysis and Design is a highly COGNITIVE activity Working with PEOPLE Working with PEOPLE What makes Systems Analysis and Design a difficult process?

Systems Analyst interactions with people during Systems Analysis & Design SYSTEMS ANALYST Users* Steering Committee* Vendors Programmers & Tech. Staff Database Administrators Managers* * = Stakeholders Systems Analyst may be acting as a Project Manager for some of these interactions.

What does a Systems Analyst do? Studies the problems and needs of an organization looking for improvement opportunities: Studies the problems and needs of an organization looking for improvement opportunities: increasing revenue/profit increasing revenue/profit decreasing costs decreasing costs improving quality of service improving quality of service add new system capabilities to enhance company’s competitiveness add new system capabilities to enhance company’s competitiveness

What is a Systems Analyst responsible for? What is a Systems Analyst responsible for? Effective and efficient: Effective and efficient: CAPTURE of input data CAPTURE of input data PROCESSING & STORAGE of data PROCESSING & STORAGE of data DELIVERY of timely and accurate information DELIVERY of timely and accurate information

Concepts & Principles Environments/Tools Problem Solving & People Skills Methods & Techniques Methodologies Skills and Competencies of a Systems Analyst Functional Business Knowledge Functional Business Knowledge Verbal & written communication skills Verbal & written communication skills Systems Analysis and Design Systems Analysis and Design work experience work experience PLUS:

Analyst Skills Required help users to determine requirements help users to determine requirements technical knowledge in a field which is constantly changing technical knowledge in a field which is constantly changing abstract or cognitive skills abstract or cognitive skills problem solving skills problem solving skills people skills people skills communication skills communication skills

Role of the Systems Analyst analyze current systems and propose new systems analyze current systems and propose new systems communicate effectively with programmers and users communicate effectively with programmers and users develop information requirements develop information requirements determine technical specifications determine technical specifications project management project management

Requirements Specification (3) General Model of Information Systems Engineering ( “ Partnership ” ) Stakeholder Information Technology Staff Analysis Design and Implementation Requirements (1) Continued Involvement (5) Information System (6) Problem Definition Skills (2) Problem Solution Skills (4)

Systems Analysis and Design Activities and Deliverables ANALYSIS Activities: Systems Planning Feasibility Study (optional) Requirements Determination User Acceptance Prototyping (optional) Deliverables: Requirements Specification Prototype (optional) DESIGN Activities: Deliverable: Physical Design Prototyping (optional) Software Construction/Purchase User Documentation Testing Training User Acceptance Conversion Implementing the system Information System Project Management Continuous Documentation Two on-going activities

Labor intensive Labor intensive smallest team = you smallest team = you next smallest team = you and one other (user) next smallest team = you and one other (user) average team = systems analysts and users average team = systems analysts and users articulation of the business problem is difficult articulation of the business problem is difficult users and systems analysts come in all sizes and shapes users and systems analysts come in all sizes and shapes Systems Analysis and Design Projects

Problems Problems Opportunities Opportunities Directives Directives Where Do Systems Analysis and Design Projects Come From?

Who Initiates Projects? users users management management systems analysts systems analysts need to comply with new industry regulations or standards need to comply with new industry regulations or standards steering committees steering committees clients or customers clients or customers

Models, Methodologies, Techniques, Tools model model –abstract representation of reality methodology methodology –systematic description of the sequence of activities required to solve a problem –ex: Booch’s object-oriented methodology

Models, Methodologies, Techniques, Tools tool tool –software product or quantative method that supports a technique –ex: Visio for drawing diagrams techniques techniques –specific activities associated with and used to implement a methodology –ex: data flow diagram

Traditional Approaches to the SDLC sequential SDLC sequential SDLC –project is divided into stages and each stage is completed before the next is started waterfall SDLC waterfall SDLC –linear approach with significant overlap between stages iterative SDLC iterative SDLC –feedback method with the ability to return to a previous stage

Four Major Categories of Models enterprise model enterprise model –graphically represents organizational entities and the relationships between entities –ex: affinity diagrams, workflow diagrams process model process model –graphical representation of the functions of a system –ex: data flow diagrams, program structure (hierarchy) charts

Four Major Categories of Models data model data model –graphical representation of system data and the relationships between data elements –ex: entity relationship diagram object model object model –represents system classes, attributes, relationships, and methods

Two Systems Development Paradigms 1. traditional development methods 1. traditional development methods –process-oriented, functional approach »Structured Methods –data-oriented »Information Engineering 2. object-oriented methods 2. object-oriented methods –define objects, attributes, and methods

Planning Planning Feasibility Study (optional) Feasibility Study (optional) Requirements Determination Requirements Determination Conceptual Design Conceptual Design Physical Design and/or Purchase (prototype) Physical Design and/or Purchase (prototype) Conversion - old to new Conversion - old to new Training Training Implementation Implementation Evolution - maintenance & enhancements Evolution - maintenance & enhancements SYSTEMS DEVELOPMENT LIFE CYCLE (SDLC) Analysis Design

Traditional SDLC Methodologies Sequential or Traditional SDLC 1. Planning for an information system 2. Feasibility Study (optional) 3. Requirements Determination (gathering) 4. Conceptual design 5. Physical design and/or purchase and/or prototyping 6. Conversion from current system to new/changed system 7. Training 8. Implementation 9. Evolution for enhancements and maintenance Waterfall or Staircase SDLC Planning Feasibility Study Requirements Determination Conceptual Design Physical Design Conversion Training Implementation Evolution

Traditional SDLC Methodologies Planning Feasibility Study Requirements Determination Conceptual Design Physical Design Conversion Training Implementation Evolution Iterative SDLC Risk Analysis Spiral SDLC SDLC Activities Verification/Test

The system is for the user The system is for the user A methodology- such as the SDLC - should be used A methodology- such as the SDLC - should be used Systems analysis and design is iterative and overlapping Systems analysis and design is iterative and overlapping Information systems are capital investments Information systems are capital investments Project manager can cancel a project Project manager can cancel a project Documentation is important all along the way Documentation is important all along the way Senior management approval/support is very important Senior management approval/support is very important Principles to Guide Systems Analysis & Design