34
Chapter 6 : Chapter 6 : Determining System Requirements Determining System Requirements

Chapter 6 : Determining System Requirementslms.mju.ac.th/courses/11/locker/system analysis and design/part06.pdf · Chapter 6 : Determining System Requirements. Performing Requirements

Embed Size (px)

Citation preview

Chapter 6 :Chapter 6 :Determining System RequirementsDetermining System Requirements

Performing Requirements Performing Requirements DeterminationDetermination

Gather information on what system Gather information on what system should do from many sourcesshould do from many sources

UsersUsersReportsReportsFormsFormsProceduresProcedures

Performing Requirements Performing Requirements DeterminationDetermination

Characteristics for gathering requirementsCharacteristics for gathering requirementsImpertinenceImpertinenceQuestion everythingQuestion everything

ImpartialityImpartialityFind the best organizational solutionFind the best organizational solution

Relaxation of constraintsRelaxation of constraintsAttention to detailAttention to detailReframingReframingView the organization in new waysView the organization in new ways

Performing Requirements Performing Requirements DeterminationDetermination

Components of an organization you Components of an organization you need to understand:need to understand:

The business objectives that drive what The business objectives that drive what and how work is doneand how work is doneThe information people need to do their The information people need to do their jobsjobsThe data (definition, volume, size) handled The data (definition, volume, size) handled within the organization to support the jobswithin the organization to support the jobsWhen, how, and by whom or what the data When, how, and by whom or what the data are moved, transformed, and storedare moved, transformed, and stored

Performing Requirements Performing Requirements DeterminationDetermination

The sequence and other dependencies The sequence and other dependencies among different dataamong different data--handling activitieshandling activitiesThe rules governing how data are handled The rules governing how data are handled and processedand processedPolicies and guidelines that describe the Policies and guidelines that describe the nature of the business and the market and nature of the business and the market and environment in which it operatesenvironment in which it operatesKey events affecting data values and when Key events affecting data values and when these events occurthese events occur

Traditional Methods for Determining Traditional Methods for Determining RequirementsRequirements

Interviewing and ListeningInterviewing and ListeningGather facts, opinions and speculationsGather facts, opinions and speculationsObserve body language and emotionsObserve body language and emotionsGuidelinesGuidelinesPlanPlan

ChecklistChecklistAppointmentAppointment

Be neutralBe neutralListenListenSeek a diverse viewSeek a diverse view

Traditional Methods for Determining Traditional Methods for Determining RequirementsRequirements

Steps in Interviewing :Steps in Interviewing :

1.Read Background Material1.Read Background Material2.Establish interviewing objectives2.Establish interviewing objectives3.Decide who to Interview3.Decide who to Interview4.Prepare the Interviewee4.Prepare the Interviewee5.Decide on Question types and Structure5.Decide on Question types and Structure

Traditional Methods for Determining Traditional Methods for Determining RequirementsRequirements

Interviewing (Continued)Interviewing (Continued)Interview QuestionsInterview Questions•• OpenOpen--EndedEnded

No preNo pre--specified answersspecified answers•• CloseClose--EndedEnded

Respondent is asked to choose from a set of specified Respondent is asked to choose from a set of specified responsesresponses

Additional GuidelinesAdditional Guidelines•• Do not phrase questions in ways that imply a wrong Do not phrase questions in ways that imply a wrong

or right answeror right answer•• Listen very carefully to what is being saidListen very carefully to what is being said•• Type up notes within 48 hoursType up notes within 48 hours•• Do not set expectations about the new systemDo not set expectations about the new system

Traditional Methods for Determining Traditional Methods for Determining RequirementsRequirements

Type of InterviewType of Interview

Unstructured Interview Unstructured Interview Structured InterviewStructured Interview

Traditional Methods for Determining Traditional Methods for Determining RequirementsRequirements

QuestionnairesQuestionnairesMore costMore cost--effective than interviewseffective than interviewsChoosing respondentsChoosing respondentsShould be representative of all usersShould be representative of all users•• Types of samplesTypes of samples

ConvenientConvenientRandom sampleRandom samplePurposeful samplePurposeful sampleStratified sampleStratified sample

Traditional Methods for Determining Traditional Methods for Determining RequirementsRequirements

The Need for Sampling :

• Containing Cost

• Speeding up the data gathering

• Improve Effectiveness

• Reducing bias

Traditional Methods for Determining Traditional Methods for Determining RequirementsRequirements

QuestionnairesQuestionnairesDesignDesignMostly closedMostly closed--ended questionsended questionsCan be administered easyCan be administered easy

Vs. InterviewsVs. InterviewsInterviews cost more but yield more informationInterviews cost more but yield more informationQuestionnaires are more costQuestionnaires are more cost--effectiveeffective

Traditional Methods for Determining Traditional Methods for Determining RequirementsRequirements

Questionnaires formats :Questionnaires formats :1.Should not have over load question1.Should not have over load question2.Use attractive method and allow ample 2.Use attractive method and allow ample white spacewhite space3.If use open end question must have 3.If use open end question must have enough spaceenough space4.If use choice answer choose write clear 4.If use choice answer choose write clear instructioninstruction

Traditional Methods for Determining Traditional Methods for Determining RequirementsRequirements

Questionnaires formats :Questionnaires formats :5.Design the question in questionnaire 5.Design the question in questionnaire from the purposefrom the purpose6.Use the consistency for design 6.Use the consistency for design questionnaire approach questionnaire approach 7.Organize questionnaire by order and 7.Organize questionnaire by order and categorizecategorize8.Do not use the flexible question for the 8.Do not use the flexible question for the first of questionnairefirst of questionnaire

Traditional Methods for Determining Traditional Methods for Determining RequirementsRequirements

Type of Questionnaires Type of Questionnaires 1.Free format : used open end question 1.Free format : used open end question

in this questionnairein this questionnaire2.Fix format : used close end question in 2.Fix format : used close end question in

this questionnairethis questionnaire2.1 Multiple choice2.1 Multiple choice2.2 Rating question2.2 Rating question2.3 Ranking question2.3 Ranking question

Traditional Methods for Determining Traditional Methods for Determining RequirementsRequirements

Interviewing GroupsInterviewing GroupsAdvantagesAdvantages•• More effective use of timeMore effective use of time•• Enables people to hear opinions of others and to Enables people to hear opinions of others and to

agree or disagreeagree or disagreeDisadvantagesDisadvantages•• Difficulty in schedulingDifficulty in scheduling

Traditional Methods for Determining Traditional Methods for Determining RequirementsRequirements

Directly Observing UsersDirectly Observing UsersServes as a good method to supplement Serves as a good method to supplement interviewsinterviewsOften difficult to obtain unbiased dataOften difficult to obtain unbiased data•• People often work differently when being People often work differently when being

observedobserved

Type of Observing MethodsType of Observing Methods•• Observing by timeObserving by time•• Observing by activityObserving by activity

Traditional Methods for Determining Traditional Methods for Determining RequirementsRequirements

Structured Observation of the environmentStructured Observation of the environmentOffice locationOffice locationDesk positionDesk positionEquipment such as fileEquipment such as fileProps such as pen ,pencil Props such as pen ,pencil Journal such as NewspaperJournal such as NewspaperLighting and color in roomLighting and color in roomDress of Interviewee Dress of Interviewee

Analyzing Procedures and Other Analyzing Procedures and Other DocumentsDocuments

Types of information to be discovered:Types of information to be discovered:Problems with existing systemProblems with existing systemOpportunity to meet new needOpportunity to meet new needOrganizational directionOrganizational directionNames of key individualsNames of key individualsValues of organizationValues of organizationSpecial information processing circumstancesSpecial information processing circumstancesReasons for current system designReasons for current system designRules for processing dataRules for processing data

Analyzing Procedures and Other Analyzing Procedures and Other DocumentsDocuments

Four types of useful documentsFour types of useful documentsWritten work proceduresWritten work procedures

•• Describes how a job is performedDescribes how a job is performed•• Includes data and information used and created in the Includes data and information used and created in the

process of performing the job or taskprocess of performing the job or task

Business formBusiness form•• Explicitly indicate data flow in or out of a systemExplicitly indicate data flow in or out of a system

Report Report •• Enables the analyst to work backwards from the report to Enables the analyst to work backwards from the report to

the data that generated itthe data that generated it

Description of current information systemDescription of current information system

Analyzing Procedures and Other Analyzing Procedures and Other DocumentsDocuments

Other two types of documentsOther two types of documentsQuantitative DocumentQuantitative Document

•• Almost of data are numberAlmost of data are number•• Such as financial or accounting statementSuch as financial or accounting statement

Qualitative DocumentQualitative Document•• Almost of data are text Almost of data are text •• Such as businessSuch as business’’s policy Business visions policy Business vision

Example Example of A Work of A Work ProcedureProcedure

A Blank A Blank Invoice Invoice

(Business (Business Form)Form)

Financial Financial Highlights Highlights

ReportReport

Modern Methods for Determining Modern Methods for Determining RequirementsRequirements

Joint Application Design (JAD)Joint Application Design (JAD)Brings together key users, managers and Brings together key users, managers and systems analystssystems analystsPurpose: collect system requirements Purpose: collect system requirements simultaneously from key peoplesimultaneously from key peopleConducted offConducted off--sitesite

Joint Application Design (JAD)Joint Application Design (JAD)

ParticipantsParticipantsSession LeaderSession LeaderUsersUsersManagersManagersSponsorSponsorSystems AnalystsSystems AnalystsScribeScribeIS StaffIS Staff

Joint Application Design (JAD)Joint Application Design (JAD)

End ResultEnd ResultDocumentation detailing existing systemDocumentation detailing existing systemFeatures of proposed systemFeatures of proposed system

CASE Tools During JADCASE Tools During JADUpper CASE tools are used Upper CASE tools are used Enables analysts to enter system models directly Enables analysts to enter system models directly into CASE during the JAD sessioninto CASE during the JAD sessionScreen designs and prototyping can be done Screen designs and prototyping can be done during JAD and shown to usersduring JAD and shown to users

Joint Application Design (JAD)Joint Application Design (JAD)

Supporting JAD with GSSSupporting JAD with GSSGroup support systems (GSS) can be used Group support systems (GSS) can be used to enable more participation by group to enable more participation by group members in JADmembers in JADMembers type their answers into the Members type their answers into the computercomputerAll members of the group see what other All members of the group see what other members have been typingmembers have been typing

Business Process Reengineering Business Process Reengineering (BPR)(BPR)

Search for and implementation of Search for and implementation of radical change in business processes to radical change in business processes to achieve breakthrough improvements in achieve breakthrough improvements in products and servicesproducts and servicesGoalsGoals

Reorganize complete flow of data in major Reorganize complete flow of data in major sections of an organizationsections of an organizationEliminate unnecessary stepsEliminate unnecessary steps

Business Process Reengineering Business Process Reengineering (BPR)(BPR)

Goals (Continued)Goals (Continued)Combine stepsCombine stepsBecome more responsive to future changeBecome more responsive to future change

Identification of processes to reengineerIdentification of processes to reengineerKey business processesKey business processes•• Set of activities designed to produce specific Set of activities designed to produce specific

output for a particular customer or marketoutput for a particular customer or market•• Focused on customers and outcomeFocused on customers and outcome•• Same techniques are used as were used for Same techniques are used as were used for

requirements determinationrequirements determination

Business Process Business Process Reengineering (BPR)Reengineering (BPR)

Identify specific activities that can be Identify specific activities that can be improved through BPRimproved through BPRDisruptive technologiesDisruptive technologies

Technologies that enable the breaking of Technologies that enable the breaking of longlong--held business rules that inhibit held business rules that inhibit organizations from making radical business organizations from making radical business changeschanges

Quiz !!!!!!!!!!What are the different things between

Time observation and Activity observation???

Example for the open end question and close end question that use in questionnaires ????