02.Systems Analysis and Design.ppt

Rakesh S. PandyaRakesh S. Pandya

Systems Analysis & DesignSystems Analysis & Design

ObjectivesObjectivesWhat are information systems, and their purpose?What are information systems, and their purpose?What is the role an employee play in the What is the role an employee play in the

development and use of information systems?development and use of information systems?Who are information system users? How is the Who are information system users? How is the

definition changing in today’s environment?definition changing in today’s environment?What are systems analysis and design?What are systems analysis and design?Where do systems analysts work?Where do systems analysts work?What modern business and technology trends are What modern business and technology trends are

affecting information systems development?affecting information systems development?What are various steps in designing a system?What are various steps in designing a system?

2 Systems Analysis and Design - (RS Systems Analysis and Design - (RS Pandya)Pandya)

Information Systems (IS) & Information Systems (IS) & Information Technology (IT)Information Technology (IT)An information system (IS) is an arrangement An information system (IS) is an arrangement of people, data, processes, communications, of people, data, processes, communications, and information technology that interact to and information technology that interact to support and improve day-to-day operations in support and improve day-to-day operations in a business, as well as support the problem-a business, as well as support the problem-solving and decision-making needs of solving and decision-making needs of management and users.management and users.

Information technology (IT) is a contemporary Information technology (IT) is a contemporary term that describes the combination of term that describes the combination of computer technology (hardware and software) computer technology (hardware and software) with telecommunications technology (data, with telecommunications technology (data, image, and voice networks).image, and voice networks).


Stakeholders for SystemStakeholders for SystemA stakeholder is any person who has an A stakeholder is any person who has an

interest in an existing or new information interest in an existing or new information system. Stakeholders can be technical or system. Stakeholders can be technical or nontechnical workers.nontechnical workers.

For information systems, the stakeholders For information systems, the stakeholders can be classified as:can be classified as:System owners ( Department, User)System owners ( Department, User)System users (Self , Internal and External)System users (Self , Internal and External)Systems analysts (IT professionals, Sys. Systems analysts (IT professionals, Sys.

Owners)Owners)System designers (IT Professionals)System designers (IT Professionals)System buildersSystem buildersIT vendors and consultantsIT vendors and consultants


55 Systems Analysis and Design - (RS Pandya)Systems Analysis and Design - (RS Pandya)

Building Blocks (Pillars) of a SystemBuilding Blocks (Pillars) of a System

Approaches for System Approaches for System AnalysisAnalysis

Problem-SolvingProblem-SolvingTrue problem situations, either real or True problem situations, either real or

anticipated, that require corrective actionanticipated, that require corrective actionOpportunities to improve a situation Opportunities to improve a situation

despite the absence of complaints despite the absence of complaints Directives to change a situation Directives to change a situation

regardless of whether anyone has regardless of whether anyone has complained about the current situationcomplained about the current situation


Approaches for System Approaches for System AnalysisAnalysis

1. Identify the problem.1. Identify the problem.2. Analyze and understand the problem.2. Analyze and understand the problem.3. Identify solution requirements or 3. Identify solution requirements or

expectations.expectations.4. Identify alternative solutions and decide a 4. Identify alternative solutions and decide a

course of action.course of action.5. Design and implement the “best” solution.5. Design and implement the “best” solution.6. Evaluate the results. If the problem is not 6. Evaluate the results. If the problem is not

solved, return to step 1 or 2 as appropriate.solved, return to step 1 or 2 as appropriate.7 Systems Analysis and Design - (RS Systems Analysis and Design - (RS

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Business Trends and DriversBusiness Trends and DriversTotal quality management (TQM)Total quality management (TQM)Continuous process improvement (CPI)Continuous process improvement (CPI)Globalization of the economyGlobalization of the economyInformation technology problems and Information technology problems and

opportunitiesopportunitiesYear 2000 problem (Y2K)Year 2000 problem (Y2K)Euro currency directiveEuro currency directiveEnterprise resource planning (ERP)Enterprise resource planning (ERP)Electronic commerce (EC or E-commerce)Electronic commerce (EC or E-commerce)


The Systems Analyst as a The Systems Analyst as a FacilitatorFacilitator


Skills Required by Systems Skills Required by Systems AnalystsAnalysts

Working knowledge of information technologyWorking knowledge of information technologyComputer programming experience & Computer programming experience &

expertiseexpertiseGeneral business knowledgeGeneral business knowledgeProblem-solving skillsProblem-solving skillsInterpersonal communication skillsInterpersonal communication skillsInterpersonal relations skillsInterpersonal relations skillsFlexibility and adaptabilityFlexibility and adaptabilityCharacter and ethicsCharacter and ethicsSystems analysis and design skillsSystems analysis and design skills


INFORMATION SYSTEM INFORMATION SYSTEM BUILDING BUILDING BLOCKSBLOCKS


Building Blocks an Information Building Blocks an Information SystemSystem

The building blocks for an Information System can The building blocks for an Information System can be :be :

Data, Information, Process and their Interfaces .Data, Information, Process and their Interfaces .information technologyinformation technologyUsers at front- and back-office of the organizationUsers at front- and back-office of the organizationDescribe five classes of information system Describe five classes of information system

applications (transaction processing, management applications (transaction processing, management information, decision support, expert, and office information, decision support, expert, and office automation systems) and how they interoperate.automation systems) and how they interoperate.

Various groups of stakeholders in information Various groups of stakeholders in information system development.system development.

The focuses for information systems.The focuses for information systems.


Building Blocks an Information Building Blocks an Information SystemSystem


Data and InformationData and InformationData are raw facts about the organization Data are raw facts about the organization and its business transactions. Most data and its business transactions. Most data items have little meaning and use by items have little meaning and use by themselves.themselves.

Information is data that has been refined Information is data that has been refined and organized by processing and purposeful and organized by processing and purposeful intelligence. The latter, purposeful intelligence. The latter, purposeful intelligence, is crucial to the definition—intelligence, is crucial to the definition—People provide the purpose and the People provide the purpose and the intelligence that produces true information.intelligence that produces true information.


Information Systems & Information Systems & TechnologyTechnologyAn information system (IS) is an arrangement An information system (IS) is an arrangement of people, data, processes, communications, of people, data, processes, communications, and information technology that interact to and information technology that interact to support and improve day-to-day operations in support and improve day-to-day operations in a business as well as support the problem-a business as well as support the problem-solving and decision making needs of solving and decision making needs of management and users.management and users.

Information technology is a contemporary Information technology is a contemporary term that describes the combination of term that describes the combination of computer technology (hardware and software) computer technology (hardware and software) with telecommunications technology (data, with telecommunications technology (data, image, and voice networks).image, and voice networks).


Front-Office & Back-Office Front-Office & Back-Office Information SystemsInformation Systems

Front-office information systems support Front-office information systems support business functions that reach out to customers business functions that reach out to customers (or constituents).(or constituents).MarketingMarketingSalesSalesCustomer managementCustomer management

Back-office information systems support Back-office information systems support internal business operations and interact with internal business operations and interact with suppliers (of materials, equipment, supplies, suppliers (of materials, equipment, supplies, and services). and services). Human resourcesHuman resourcesFinancial managementFinancial managementManufacturingManufacturing Inventory controlInventory control


Front-Office & Back-Office Front-Office & Back-Office Information SystemsInformation Systems


Classes of Information Classes of Information SystemsSystems

Transaction processing systemsTransaction processing systemsManagement information systemsManagement information systemsDecision support systemsDecision support systemsExpert systemsExpert systemsOffice automation systemsOffice automation systems


Information Systems ApplicationsInformation Systems Applications


Information System Building Information System Building BlocksBlocks


The DATA FocusThe DATA Focus


The PROCESS FocusThe PROCESS Focus


The INTERFACE FocusThe INTERFACE Focus


Information System Building Information System Building BlocksBlocks


The Role of the Network in ISThe Role of the Network in IS


INFORMATION SYSTEM INFORMATION SYSTEM DEVELOPMENTDEVELOPMENT


Information System DevelopmentInformation System Development A system development process required to achieve the A system development process required to achieve the

Capability Maturity Model (CMM) for quality management.Capability Maturity Model (CMM) for quality management. Every system has its life cycle and development methodology.Every system has its life cycle and development methodology. There are eight basic principles of system development which There are eight basic principles of system development which

includes definition of problems, opportunities, and directives.includes definition of problems, opportunities, and directives. In early days there were traditional and basic phases of In early days there were traditional and basic phases of

system development. Every phase includes the purpose, system development. Every phase includes the purpose, inputs, and outputs.inputs, and outputs.

Later new methods of system development includes Later new methods of system development includes computer-aided systems engineering (CASE), application computer-aided systems engineering (CASE), application development environments (ADEs), and process and project development environments (ADEs), and process and project management technology as automated tools for system management technology as automated tools for system development.development.


Building Blocks for Information Building Blocks for Information System DevelopmentSystem Development


The CMM Process Management The CMM Process Management ModelModel

The Capability Maturity Model (CMM) is a framework The Capability Maturity Model (CMM) is a framework to assess the maturity level of an organization’s to assess the maturity level of an organization’s information system development and management information system development and management processes and products. It consists of five levels of processes and products. It consists of five levels of maturity as measured by a set of guidelines called maturity as measured by a set of guidelines called the key process areas.the key process areas.

Level 1Level 1 - - Initial:Initial: System development projects follow no prescribed System development projects follow no prescribed process.process.

Level 2Level 2 - - Repeatable:Repeatable: Project management processes and practices Project management processes and practices are established to track project costs, schedules, and functionality. are established to track project costs, schedules, and functionality.

Level 3Level 3 - - Defined: Defined: A standard system development process A standard system development process (sometimes called a “methodology”) is purchased or developed, and (sometimes called a “methodology”) is purchased or developed, and integrated throughout the information systems/services unit of the integrated throughout the information systems/services unit of the organization. organization.

Level 4Level 4 - - Managed:Managed: Measurable goals for quality and productivity are Measurable goals for quality and productivity are established. established.

Level 5Level 5 - - Optimizing:Optimizing: The standardized system development process The standardized system development process is continuously monitored and improved based on measures and data is continuously monitored and improved based on measures and data analysis established in Level 4. analysis established in Level 4.


Capability Maturity Model (CMM)Capability Maturity Model (CMM)


Life Cycle versus Life Cycle versus MethodologyMethodology

A system life cycle divides the life of an A system life cycle divides the life of an information system into two stages, information system into two stages, systems development and systems systems development and systems operation and support.operation and support.

A system development methodology is a A system development methodology is a very formal and precise system very formal and precise system development process that defines (as in development process that defines (as in CMM Level 3) a set of activities, methods, CMM Level 3) a set of activities, methods, best practices, deliverables, and best practices, deliverables, and automated tools that system developers automated tools that system developers and project managers are to use to develop and project managers are to use to develop and maintain information systems and and maintain information systems and software.software.


A System Life CycleA System Life Cycle


Principles of System Principles of System DevelopmentDevelopmentGet the owners and users involved.Get the owners and users involved.Use a problem-solving approach.Use a problem-solving approach.Establish phases and activities.Establish phases and activities.Establish standards.Establish standards.Justify systems as capital investments.Justify systems as capital investments.Don’t be afraid to cancel or revise Don’t be afraid to cancel or revise

scope.scope.Divide and conquer.Divide and conquer.Design systems for growth and change.Design systems for growth and change.


Phases of a Representative Phases of a Representative MethodologyMethodology


Overlap of System Development Overlap of System Development PhasesPhases


The The PIECESPIECES Problem-Solving Problem-Solving FrameworkFramework

PP the need to improve the need to improve PPerformanceerformance II the need to improve the need to improve IInformation (& data)nformation (& data)EE the need to improve the need to improve EEconomics, control conomics, control

costs, or increase profitscosts, or increase profitsCC the need to improve the need to improve CControl or securityontrol or securityEE the need to improve the need to improve EEfficiency of people fficiency of people

and processesand processesSS the need to improve the need to improve SService to customers, ervice to customers,

suppliers, partners, employees, etc.suppliers, partners, employees, etc.


FASTFAST System Development System Development PhasesPhases


Cross Life Cycle ActivitiesCross Life Cycle ActivitiesCross life cycle activities are activities that Cross life cycle activities are activities that overlap many or all phases of the overlap many or all phases of the methodology.methodology.

Fact-findingFact-finding

Documentation and presentationDocumentation and presentation

Feasibility analysisFeasibility analysis

Process and project managementProcess and project management


A repository is a database where system developers store all documentation, knowledge, and products for one or more information systems or projects.

Sharing Knowledge via a Sharing Knowledge via a RepositoryRepository


Alternative Methodology for Alternative Methodology for Systems DevelopmentSystems Development

Model-Driven Development (MDD)Model-Driven Development (MDD)Rapid Application Development (RAD)Rapid Application Development (RAD)Commercial Off-the-Shelf Software (COTS)Commercial Off-the-Shelf Software (COTS)Maintenance and ReengineeringMaintenance and Reengineering

or hybrids of the aboveor hybrids of the above


Model-Driven Development (MDD)Model-Driven Development (MDD)


Rapid Application Development Rapid Application Development (RAD)(RAD)


Commercial Off-the-Shelf (COTS)Commercial Off-the-Shelf (COTS)


Hybrid: Rapid Architected Hybrid: Rapid Architected DevelopmentDevelopment


Hybrid: Multiple ImplementationHybrid: Multiple Implementation


Hybrid: Staged Hybrid: Staged ImplementationImplementation


Maintenance and Reengineering Maintenance and Reengineering RouteRoute


Automated Tools and TechnologyAutomated Tools and Technology

Computer-aided systems engineering Computer-aided systems engineering (CASE)(CASE)

Application development environments Application development environments (ADEs)(ADEs)

Process and project managersProcess and project managers


CASE Tools CASE Tools (Computer Added Software Engineering (Computer Added Software Engineering Tools)Tools)Software Engineering is the establishment and use of sound Software Engineering is the establishment and use of sound engineering principles in order to obtain economically engineering principles in order to obtain economically software that is reliable and works efficiently on real software that is reliable and works efficiently on real machines.machines.CASE is an application of a systematic, disciplined, CASE is an application of a systematic, disciplined, quantifiable approach to the development, operation and quantifiable approach to the development, operation and maintenance of software i.e. the application of engineering to maintenance of software i.e. the application of engineering to software.software.CASE provides automation and aided design to developers in CASE provides automation and aided design to developers in almost every single developer program for the last couple almost every single developer program for the last couple decadesdecadesCASE Tool and Method Categories -CASE Tool and Method Categories -

Data ModellingData Modelling Model and Program TransformationModel and Program Transformation Refactoring toolsRefactoring tools Source code generationSource code generation Unified Modelling LanguageUnified Modelling Language DocumentationDocumentation49 Systems Analysis and Design - (RS Systems Analysis and Design - (RS

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CASE Tools CASE Tools (Computer Added Software Engineering (Computer Added Software Engineering Tools)Tools) ProcessProcess Provides the glue that holds the Provides the glue that holds the

layers together; enables rational and layers together; enables rational and timely development; provides a timely development; provides a framework for effective delivery of framework for effective delivery of technology; forms the basis for technology; forms the basis for management; provides the context management; provides the context for technical methods, work for technical methods, work products, milestones, quality products, milestones, quality measures, and change managementmeasures, and change management

MethodsMethods Provide the technical "how to" for Provide the technical "how to" for

building software; rely on a set of building software; rely on a set of basic principles; encompass a broad basic principles; encompass a broad array of tasks; include modeling array of tasks; include modeling activitiesactivities

ToolsTools Provide automated or semi-Provide automated or semi-

automated support for the process automated support for the process and methods (i.e., CASE tools)and methods (i.e., CASE tools)


ToolsTools

MethodsMethods

ProcessesProcesses

Quality Quality FocusFocus

CASE ArchitectureCASE Architecture


Activity cost distributionActivity cost distribution

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ADE ToolsADE ToolsApplication development environments (ADEs) Application development environments (ADEs) are integrated software development tools that are integrated software development tools that provide all the facilities necessary to develop provide all the facilities necessary to develop new application software with maximum speed new application software with maximum speed and quality. A common synonym is and quality. A common synonym is integrated integrated development environmentdevelopment environment (IDE) (IDE)

ADE facilities may include:ADE facilities may include: Programming languages or interpretersProgramming languages or interpreters Interface construction toolsInterface construction tools MiddlewareMiddleware Testing toolsTesting tools Version control toolsVersion control tools Help authoring toolsHelp authoring tools Repository linksRepository links


SYSTEMSSYSTEMSANALYSISANALYSIS


Objectives of Systems Objectives of Systems AnalysisAnalysis

Systems analysis includes Systems analysis includes preliminary investigation, preliminary investigation, problem analysis, problem analysis, requirements analysis, and requirements analysis, and decision analysis phasesdecision analysis phasesnumber of approaches for solving business number of approaches for solving business system problems. system problems. This relates with information system building This relates with information system building blocks, with inputs, outputs, techniques, and blocks, with inputs, outputs, techniques, and steps.steps.


Systems Analysis vs. Systems Analysis vs. Systems DesignSystems Design

Systems analysis Systems analysis is a problem-solving is a problem-solving technique that decomposes a system into its technique that decomposes a system into its component pieces for the purpose of studying component pieces for the purpose of studying how well those component parts work and how well those component parts work and interact to accomplish their purpose.interact to accomplish their purpose.Systems design Systems design (also called systems (also called systems synthesis) is a complementary problem-synthesis) is a complementary problem-solving technique (to systems analysis) that solving technique (to systems analysis) that reassembles a system’s component pieces reassembles a system’s component pieces back into a complete system - hopefully, an back into a complete system - hopefully, an improved system. This may involves adding, improved system. This may involves adding, deleting, and changing pieces relative to the deleting, and changing pieces relative to the original system. original system.


Systems Analysis involvesSystems Analysis involves


Context of Systems AnalysisContext of Systems Analysis


Model-Driven Analysis Model-Driven Analysis MethodsMethods

Model-driven analysis emphasizes the drawing of Model-driven analysis emphasizes the drawing of pictorial system models to document and validate pictorial system models to document and validate both existing and/or proposed systems. Ultimately, both existing and/or proposed systems. Ultimately, the system model becomes the blueprint for the system model becomes the blueprint for designing and constructing an improved system.designing and constructing an improved system.

A model is a representation of either reality or A model is a representation of either reality or vision. Just as “a picture is worth a thousand vision. Just as “a picture is worth a thousand words,” most models use pictures to represent the words,” most models use pictures to represent the reality or vision.reality or vision.


Model-Driven MethodsModel-Driven MethodsStructured analysis is a model-driven, process-centered Structured analysis is a model-driven, process-centered technique used to either analyze an existing system, define technique used to either analyze an existing system, define business requirements for a new system, or both. The models business requirements for a new system, or both. The models are pictures that illustrate the system’s component pieces: are pictures that illustrate the system’s component pieces: processes and their associated inputs, outputs, and files.processes and their associated inputs, outputs, and files.

Information engineering (IE) is a model-driven and data-Information engineering (IE) is a model-driven and data-centered, but process-sensitive technique to plan, analyze, centered, but process-sensitive technique to plan, analyze, and design information systems. IE models are pictures that and design information systems. IE models are pictures that illustrate and synchronize the system’s data and processes.illustrate and synchronize the system’s data and processes.

Object-oriented analysis (OOA) is a model-driven technique Object-oriented analysis (OOA) is a model-driven technique that integrates data and process concerns into constructs that integrates data and process concerns into constructs called objects. OOA models are pictures that illustrate the called objects. OOA models are pictures that illustrate the system’s objects from various perspectives such as structure system’s objects from various perspectives such as structure and behavior.and behavior.


A Simple Process ModelA Simple Process Model


A Simple Data ModelA Simple Data Model


A Simple Object ModelA Simple Object Model

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Accelerated Analysis MethodsAccelerated Analysis MethodsAccelerated analysis approaches emphasize Accelerated analysis approaches emphasize the construction of prototypes to more the construction of prototypes to more rapidly identify business and user rapidly identify business and user requirements for a new system.requirements for a new system.

A prototype is a small-scale, incomplete, but A prototype is a small-scale, incomplete, but workingworking sample of a desired system. sample of a desired system. Prototypes cater to the “I’ll know what I Prototypes cater to the “I’ll know what I want when I see it” way of thinking that is want when I see it” way of thinking that is characteristic of many users and managers.characteristic of many users and managers.


Accelerated Analysis MethodsAccelerated Analysis MethodsDiscovery prototyping (sometimes called Discovery prototyping (sometimes called requirements prototypingrequirements prototyping) is used to identify the ) is used to identify the users’ business requirements by having them react users’ business requirements by having them react to a quick-and-dirty implementation of those to a quick-and-dirty implementation of those requirements.requirements.

Rapid architecture analysis is an approach that Rapid architecture analysis is an approach that attempts to derive system models (as described attempts to derive system models (as described earlier in this section) from existing systems or earlier in this section) from existing systems or discovery prototypes.discovery prototypes. Reverse engineering technology reads the Reverse engineering technology reads the

program code for a database, application program code for a database, application program, and/or user interface and automatically program, and/or user interface and automatically generates the equivalent system model.generates the equivalent system model.


Requirements Discovery MethodsRequirements Discovery MethodsRequirements discovery includes those Requirements discovery includes those

techniques to be used by systems analysts to techniques to be used by systems analysts to identify or extract system problems and identify or extract system problems and solution requirements from the user solution requirements from the user community.community. Fact-finding (or information gathering) is a Fact-finding (or information gathering) is a

classical set of techniques used to collect classical set of techniques used to collect information about system problems, opportunities, information about system problems, opportunities, solution requirements, and priorities. solution requirements, and priorities. SamplingSampling ResearchResearch ObservationObservation Questionnaires and surveysQuestionnaires and surveys InterviewsInterviews

Joint requirements planning (JRP) techniques use Joint requirements planning (JRP) techniques use facilitated workshops to bring together all of the facilitated workshops to bring together all of the system owners, system users, systems analysts, system owners, system users, systems analysts, and some systems designer and builders to jointly and some systems designer and builders to jointly perform systems analysis. perform systems analysis.


Business Process Redesign Business Process Redesign MethodsMethods

Business process redesign is the application Business process redesign is the application of systems analysis methods to the goal of of systems analysis methods to the goal of dramatically changing and improving the dramatically changing and improving the fundamental business processes of an fundamental business processes of an organization, independent of information organization, independent of information technology.technology.


Systems Analysis PhasesSystems Analysis PhasesPreliminary Investigation PhasePreliminary Investigation Phase

Problem Analysis PhaseProblem Analysis Phase

Requirements Analysis PhaseRequirements Analysis Phase

Decision Analysis PhaseDecision Analysis Phase


Preliminary Investigation Phase Preliminary Investigation Phase ContextContext


Preliminary Investigation Phase Preliminary Investigation Phase TasksTasks


Sample Request for System Sample Request for System ServicesServices


Problem StatementsProblem Statements


Problem Analysis Phase Problem Analysis Phase ContextContext


Problem Analysis Phase Problem Analysis Phase ContextContext


Cause-and-Effect AnalysisCause-and-Effect AnalysisCause-and-effect analysis is a technique in Cause-and-effect analysis is a technique in which problems are studied to determine which problems are studied to determine their causes and effects. their causes and effects. In practice, effects can be symptomatic of In practice, effects can be symptomatic of more deeply rooted or basic problems more deeply rooted or basic problems which, in turn, must be analyzed for causes which, in turn, must be analyzed for causes and effects until such a time as the causes and effects until such a time as the causes and effects do not yield symptoms of other and effects do not yield symptoms of other problems.problems.


System Improvement System Improvement ObjectivesObjectives

An objective is a measure of success. It is something An objective is a measure of success. It is something that you expect to achieve, if given sufficient resources.that you expect to achieve, if given sufficient resources.Reduce the number of uncollectible customer Reduce the number of uncollectible customer

accounts by 50 percent within the next year.accounts by 50 percent within the next year.Increase by 25 percent the number of loan Increase by 25 percent the number of loan

applications that can be processed during an eight-applications that can be processed during an eight-hour shift.hour shift.

Decrease by 50 percent the time required to Decrease by 50 percent the time required to reschedule a production reschedule a production lot when a workstation malfunctions.lot when a workstation malfunctions.

A constraint is something that will limit your flexibility A constraint is something that will limit your flexibility in defining a solution to your objectives. Essentially, in defining a solution to your objectives. Essentially, constraints cannot be changed.constraints cannot be changed.


Cause-and-Effect / System Cause-and-Effect / System Improvement ObjectivesImprovement Objectives

PROBLEMS, OPPORTUNITIES, OBJECTIVES, AND CONSTRAINTS MATRIX


Requirements Analysis Phase Requirements Analysis Phase ContextContext


Requirements Analysis Phase Requirements Analysis Phase TasksTasks


Business RequirementsBusiness RequirementsA functional requirement is a description of A functional requirement is a description of activities and services a system must activities and services a system must provide.provide.

A nonfunctional requirement is a A nonfunctional requirement is a description of other features, description of other features, characteristics, and constraints that define a characteristics, and constraints that define a satisfactory system.satisfactory system.


Logical System ModelsLogical System ModelsLogical system models depict Logical system models depict whatwhat a system a system is or is or whatwhat a system must do— a system must do—notnot how the how the system will be implemented. Because logical system will be implemented. Because logical models depict the models depict the essential essential requirements of requirements of a system, they are sometimes called a system, they are sometimes called essential essential system modelssystem models.. Process models (e.g., data flow diagrams)Process models (e.g., data flow diagrams)Data models (e.g., entity relationship Data models (e.g., entity relationship

diagrams)diagrams)Interface models (e.g., context diagrams)Interface models (e.g., context diagrams)Object models (e.g., Uniform Modeling Object models (e.g., Uniform Modeling

Language diagrams)Language diagrams)81 Systems Analysis and Design - (RS Systems Analysis and Design - (RS

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A Simple Interface ModelA Simple Interface Model


Requirements StatementRequirements Statement


Decision Analysis Phase Decision Analysis Phase ContextContext


Decision Analysis Phase Decision Analysis Phase TasksTasks


Feasibility AnalysesFeasibility AnalysesTechnical feasibility. Is the solution Technical feasibility. Is the solution

technically practical? Does our staff have technically practical? Does our staff have the technical expertise to design and build the technical expertise to design and build this solution?this solution?

Operational feasibility. Will the solution Operational feasibility. Will the solution fulfill the users’ requirements? To what fulfill the users’ requirements? To what degree? How will the solution change the degree? How will the solution change the users’ work environment? How do users users’ work environment? How do users feel about such a solution?feel about such a solution?

Economic feasibility. Is the solution cost-Economic feasibility. Is the solution cost-effective?effective?

Schedule feasibility. Can the solution be Schedule feasibility. Can the solution be designed and implemented within an designed and implemented within an acceptable time period? acceptable time period?


Candidate Systems MatrixCandidate Systems Matrix

(Continued)87 Systems Analysis and Design - (RS Systems Analysis and Design - (RS Pandya)Pandya)

Candidate Systems Matrix Candidate Systems Matrix (concluded)(concluded)


Feasibility MatrixFeasibility Matrix


INPUT DESIGN AND INPUT DESIGN AND PROTOTYPINGPROTOTYPING


Input Design & PrototypingInput Design & Prototyping


Data Capture, Entry, and Data Capture, Entry, and ProcessingProcessing

Data capture Data capture is the identification and acquisition of is the identification and acquisition of new data (at its source).new data (at its source).

Source documents are forms used to record business Source documents are forms used to record business transactions in terms of data that describe those transactions in terms of data that describe those transactions.transactions.

Data entry Data entry is the process of translating the source is the process of translating the source data or document (above) into a computer readable data or document (above) into a computer readable format.format.Data processing Data processing is all processing that occurs on the is all processing that occurs on the data after it is input from a machine readable form. data after it is input from a machine readable form.

In batch processing, the entered data is collected into files In batch processing, the entered data is collected into files called batches and processed as a complete batch.called batches and processed as a complete batch.

In on-line processing, the captured data is processed In on-line processing, the captured data is processed immediatelyimmediately

In remote batch processing, data is entered and edited on-In remote batch processing, data is entered and edited on-line, but collected into batches for subsequent processing.line, but collected into batches for subsequent processing.


Taxonomy for Computer InputsTaxonomy for Computer Inputs


Data CaptureData Capture Data EntryData Entry Data ProcessingData Processing

KeyboardKeyboard

Data usually Data usually captured on a captured on a business form that business form that is the source is the source document for input.document for input.

Data can be Data can be collected real time collected real time also. also.

Data entered via Data entered via keyboard. This is keyboard. This is the most common the most common input method input method prone to data prone to data errors.errors.

OLD – Batch processing OLD – Batch processing method and submitting method and submitting outputs to user.outputs to user.

NEW – Data being NEW – Data being processed online as processed online as soon as it has been soon as it has been keyed.keyed.

MouseMouse

Same as above.Same as above. Mouse serves as a Mouse serves as a pointing device for pointing device for screen with GUI screen with GUI facilities. It can be facilities. It can be used in used in conjunction with conjunction with keyboard.keyboard.

Same as above.Same as above.

Faster use for online Faster use for online and real time data and real time data processing.processing.

Touch Touch ScreenScreen

Same as above.Same as above. Used for command Used for command rather than data rather than data entry.entry.

Can be used for Can be used for handwriting data handwriting data entry.entry.


ProcesProcesssMethodMethod

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Taxonomy for Computer InputsTaxonomy for Computer Inputs



Point of Point of SaleSale

Data is captured at Data is captured at Point of Sales on Point of Sales on line either thru line either thru keyboard or barcode keyboard or barcode reader. reader.

ATM, Barcode ATM, Barcode reader or on line reader or on line keyboards. Direct keyboards. Direct data entry.data entry.

Data is almost always Data is almost always processed immediately processed immediately for online inquiry or for online inquiry or transaction. transaction.

SoundSoundDate is captured as Date is captured as close to the source close to the source as possible even as possible even when the customer when the customer is remotely located.is remotely located.

Data is entered Data is entered using touch tones using touch tones (e.g. telephones) (e.g. telephones) with limited with limited options.options.

Processing of data is Processing of data is immediate for online immediate for online inquiry or transaction.inquiry or transaction.

SpeechSpeechSame as above.Same as above. Data (or Data (or

commands) are in commands) are in the form of the form of speech.speech.


Optical Optical MarkMark

Data is recorded on Data is recorded on optical scan sheets optical scan sheets as marks or as marks or precisely formed precisely formed letters, numbers letters, numbers and punctuation.and punctuation.

Eliminates the Eliminates the need for data need for data entry.entry.

Data is processed in a Data is processed in a batch form.batch form.


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Taxonomy for Computer Taxonomy for Computer InputsInputs



Magnetic linkMagnetic link

Data is usually pre-Data is usually pre-recorded on forms recorded on forms that are that are subsequently subsequently completed by the completed by the customer.customer.

A magnetic ink A magnetic ink reader reads the reader reads the magnetized data. magnetized data. (e.g. MICR (e.g. MICR cheques)cheques)

Data is almost Data is almost always processed as always processed as batch.batch.

ElectromagnetiElectromagneticc

Date is recorded Date is recorded directly on the directly on the object to be object to be described by data.described by data.

Data is Data is transmitted by transmitted by radio frequency.radio frequency.

Processing of data is Processing of data is immediate for online immediate for online inquiry or inquiry or transaction.transaction.

SmartcardSmartcardSame as above.Same as above. Data is read by Data is read by

smartcard smartcard readers.readers.


BiometricBiometric

Unique human Unique human characteristics characteristics become data (e.g. become data (e.g. finger prints, eye finger prints, eye retina, voice etc.)retina, voice etc.)

Data being Data being captured by captured by biometric sensor biometric sensor (used at security, (used at security, medical centers). medical centers).

Data is processed Data is processed immediately.immediately.


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Input Implementation devicesInput Implementation devicesKeyboardKeyboardMouseMousePoint-of-sale terminalsPoint-of-sale terminalsSound and speechSound and speechAutomatic data captureAutomatic data capture

Optical mark recognition (OMR)Optical mark recognition (OMR)Bar codesBar codes

Optical character recognition (OCR)Optical character recognition (OCR)Magnetic Ink character reader Magnetic Ink character reader Electromagnetic transmissionElectromagnetic transmissionSmart cards readerSmart cards readerBiometric reader and sensor Biometric reader and sensor


GuidelinesGuidelinesInput DesignInput DesignCapture only variable data.Capture only variable data.Do not capture data that can calculated or Do not capture data that can calculated or

stored in computer programs as constants.stored in computer programs as constants.Use business codes for appropriate attributes.Use business codes for appropriate attributes.Source Document / Form DesignSource Document / Form DesignInclude instructions for completing the form.Include instructions for completing the form.Minimize the amount of handwriting.Minimize the amount of handwriting.Data to be entered (keyed) should be Data to be entered (keyed) should be

sequenced so that it can be read like a book, sequenced so that it can be read like a book, that is, top-to-bottom and left-to-right.that is, top-to-bottom and left-to-right.

When possible, based input design on known When possible, based input design on known metaphors.metaphors.


Design of Data Entry FormDesign of Data Entry Form(Bad Format)(Bad Format)


Design of Data Entry FormDesign of Data Entry Form(Good Format)(Good Format)


Metaphoric Screen DesignMetaphoric Screen Design


Internal Controls for InputsInternal Controls for InputsEach input, and the total number of inputs Each input, and the total number of inputs

should be monitored (to minimize the risk of should be monitored (to minimize the risk of lost transactions).lost transactions).For batch processingFor batch processing

Use batch control slipsUse batch control slipsUse one-for-one checks against post-processing Use one-for-one checks against post-processing

detail reports detail reports For on-line systemsFor on-line systems

Log each transaction as it occursLog each transaction as it occursAssign each transaction a confirmation number Assign each transaction a confirmation number

(common in web-based systems)(common in web-based systems)Validate all dataValidate all data

Existence checksExistence checksData type checksData type checksDomain checksDomain checksCombination checksCombination checksSelf-checking digitsSelf-checking digitsFormat checksFormat checks


GUI Components (or Controls)GUI Components (or Controls)Common GUI controlsCommon GUI controls

Text boxesText boxesRadio buttonsRadio buttonsCheck boxesCheck boxesList boxesList boxesDrop down listsDrop down listsCombination boxesCombination boxesSpin boxesSpin boxesButtonsButtonsHyperlinksHyperlinks

Advanced controlsAdvanced controlsDrop down calendarsDrop down calendarsSlider edit controlsSlider edit controlsMasked edit controlsMasked edit controlsEllipsis controlsEllipsis controlsAlternate numerical spinnersAlternate numerical spinnersCheck list boxesCheck list boxesCheck tree boxesCheck tree boxes


Input Design ProcessInput Design Process Identify system inputs and review logical Identify system inputs and review logical

requirements.requirements. Select appropriate input Select appropriate input

components/controls.components/controls. As necessary, design any source documents.As necessary, design any source documents. Design, validate and test inputs using some Design, validate and test inputs using some

combination of:combination of:• Layout tools (e.g., hand sketches, spacing charts, or Layout tools (e.g., hand sketches, spacing charts, or

CASE tools.CASE tools.• Prototyping tools (e.g., spreadsheet, PC DBMS, 4GL)Prototyping tools (e.g., spreadsheet, PC DBMS, 4GL)


OUTPUT DESIGN AND PROTOTYPINGOUTPUT DESIGN AND PROTOTYPING


Output Design & PrototypingOutput Design & Prototyping


Internal OutputsInternal OutputsInternal outputs are intended for the internal Internal outputs are intended for the internal

system owners and system users within an system owners and system users within an organization.organization.

Detailed reports present information with little Detailed reports present information with little or no filtering.or no filtering.

Summary reports categorize information for Summary reports categorize information for managers who do not want to wade through managers who do not want to wade through details.details.

Increasingly presented inn graphical formats Increasingly presented inn graphical formats using charts.using charts.

Exception reports filter detailed information Exception reports filter detailed information before presenting it. before presenting it.


Detailed ReportDetailed Report


Summary ReportSummary Report


Exception ReportException Report


External OutputsExternal OutputsExternal outputs leave an organization.External outputs leave an organization.Intended for customers, suppliers, Intended for customers, suppliers,

partners, or regulatory agencies.partners, or regulatory agencies.Turnaround documents are external outputs Turnaround documents are external outputs

that eventually re-enter the system as inputsthat eventually re-enter the system as inputsMost “bills” and invoices include a stub to be Most “bills” and invoices include a stub to be

returned by the customer with payment.returned by the customer with payment.


External DocumentExternal Document


Turnaround DocumentTurnaround Document


Taxonomy for Computer OutputsTaxonomy for Computer Outputs


Internal OutputInternal Output(Reporting) (Reporting)

Turnaround Turnaround Output Output

(Reporting)(Reporting)External OutputExternal Output(Transactions) (Transactions)

PrinterPrinter

Detailed summary or Detailed summary or exception print outs exception print outs for internal usages.for internal usages.

e.g. Management e.g. Management ReportsReports

Business Business transaction outputs transaction outputs on business forms on business forms or invoices(as or invoices(as input) input) e.g. phone bills, e.g. phone bills, invoicesinvoices

Business transactions Business transactions outputs on business outputs on business forms (as processed forms (as processed output)output)e.g. cheques, dividend e.g. cheques, dividend warrant etc.warrant etc.

ScreenScreenSame as above but Same as above but outputs cab be outputs cab be viewed on monitors.viewed on monitors.

Same as above but Same as above but outputs and outputs and transactions can be transactions can be viewed and entered viewed and entered on monitors.on monitors.

Same as above but Same as above but outputs and outputs and transactions can be transactions can be viewed and entered on viewed and entered on monitors.monitors.

Point-of-Point-of-SaleSale

TerminalsTerminals

Information printed Information printed or displayed on a or displayed on a special purpose special purpose terminals dedicated terminals dedicated for specific business for specific business function.function.

e.g. shift schedule, e.g. shift schedule, railway inquiry etc.railway inquiry etc.

Information printed Information printed or displayed on a or displayed on a special purpose special purpose terminals dedicated terminals dedicated for specific for specific business business transaction.transaction.

e.g. at grocery e.g. at grocery shop, credit card shop, credit card etc.etc.

Information printed or Information printed or displayed on a special displayed on a special purpose terminals purpose terminals dedicated for specific dedicated for specific business transaction.business transaction.

e.g. at bank or on ATM e.g. at bank or on ATM machine account machine account balances are balances are displayed.displayed.

DistributioDistributionnDeliveryDelivery

Taxonomy for Computer OutputsTaxonomy for Computer Outputs


Internal OutputInternal Output(Reporting) (Reporting)

Turnaround Output Turnaround Output (Reporting)(Reporting)

External OutputExternal Output(Transactions) (Transactions)

MultimediaMultimedia(audio or (audio or

video)video)

Information Information transformed into transformed into speech for internal speech for internal users.users.

Information transformed Information transformed into speech for external into speech for external users who respond with users who respond with speech or tone input speech or tone input data.data.

Information Information transformed into transformed into speech for speech for external users.external users.

E-mailE-mailDisplayed Displayed messages related messages related to internal to internal business business information.information.

Displayed messages Displayed messages intended to initiate intended to initiate business transaction.business transaction.

Messages related Messages related to business to business transactions.transactions.

HyperlinksHyperlinks

Web-based links to Web-based links to internal internal information thru information thru HTML or XML HTML or XML formats.formats.

Web-based links Web-based links incorporated into Web-incorporated into Web-based input pages to based input pages to provide users with provide users with access to additional access to additional information.information.

Web-based links Web-based links incorporated into incorporated into Web-based Web-based transactions. transactions.

MicroficheMicrofiche

Archival of internal Archival of internal management management reports to reports to microfilm that microfilm that requires minimal requires minimal physical storage physical storage space. space.

Not applicable unless Not applicable unless there is an internal need there is an internal need to active turnaround to active turnaround documents.documents.

Not applicable Not applicable unless there is an unless there is an internal need for internal need for copies of external copies of external reports.reports.

DistributioDistributionnDeliveryDelivery

Output Implementation MethodsOutput Implementation MethodsPrinted outputPrinted output

Tabular output presents information in columns.Tabular output presents information in columns.Zoned output places text and numbers into Zoned output places text and numbers into

designated “areas”designated “areas”Screen outputScreen output

Graphic output is the use of pictorial charts to Graphic output is the use of pictorial charts to convey information in ways that demonstrate convey information in ways that demonstrate trends and relationships that cannot be easily trends and relationships that cannot be easily seen in tabular formats.seen in tabular formats.

Point-of-sale terminalsPoint-of-sale terminalsMultimediaMultimediaE-mailE-mailHyperlinksHyperlinksMicrofilmMicrofilmOr microficheOr microfiche


Output Design GuidelinesOutput Design GuidelinesOutputs should be simple to read and interpret.Outputs should be simple to read and interpret.

Every output must have a title.Every output must have a title. Every output should time and date stamped.Every output should time and date stamped. Reports and screens should include headings.Reports and screens should include headings. Fields and columns should be clearly labeled.Fields and columns should be clearly labeled. Reports should include legends for all abbreviations.Reports should include legends for all abbreviations. Use information hiding to expand and contract information.Use information hiding to expand and contract information. Information should never have to be manually edited.Information should never have to be manually edited. Information should be balanced across the page or screen.Information should be balanced across the page or screen. Provide for easy navigation within information.Provide for easy navigation within information. Avoid computer jargon and most error messages.Avoid computer jargon and most error messages.

The timing of outputs is important.The timing of outputs is important.The distribution of (or access to) outputs must The distribution of (or access to) outputs must

be sufficient to assist all relevant users.be sufficient to assist all relevant users.Outputs must be acceptable to the system users Outputs must be acceptable to the system users

who will receive them.who will receive them.


Output Design ProcessOutput Design Process Identify system outputs and review logical Identify system outputs and review logical

requirements.requirements.Specify physical output requirements.Specify physical output requirements.As necessary, design any preprinted forms.As necessary, design any preprinted forms.Design, validate and test outputs using Design, validate and test outputs using

some combination of:some combination of:o Layout tools (e.g., hand sketches, spacing Layout tools (e.g., hand sketches, spacing

charts, or CASE tools.charts, or CASE tools.o Prototyping tools (e.g., spreadsheet, PC Prototyping tools (e.g., spreadsheet, PC

DBMS, 4GL)DBMS, 4GL)o Code generating tools (e.g., report writer)Code generating tools (e.g., report writer)



A Simple Object ModelA Simple Object Model


StudentStudent-ID Master-ID Master-Name-Name-Grade Point Average-Grade Point Average

AdmissionAdmissionSpecialization subjectSpecialization subjectRequest for ClassesRequest for ClassesChange of AddressChange of AddressResultResultCollage leaving Collage leaving CertificateCertificate

CourseCourse-Subject-Subject-Number-Number-Title-Title-Credit-Credit

Create a CourseCreate a CourseDelete from Course Delete from Course mastermasterChange in Course masterChange in Course master

Documents

02.Systems Analysis and Design.ppt