14. CONTROLLING

INFORMATION

SYSTEMS

14. CONTROLLING

INFORMATION

SYSTEMS

14.1

THREATS TO INFORMATION SYSTEMS

THREATS TO INFORMATION SYSTEMS

HARDWARE FAILURE, FIREHARDWARE FAILURE, FIRE

SOFTWARE FAILURE, ELECTRICAL PROBLEMSSOFTWARE FAILURE, ELECTRICAL PROBLEMS

PERSONNEL ACTIONS, USER ERRORSPERSONNEL ACTIONS, USER ERRORS

ACCESS PENETRATION, PROGRAM CHANGESACCESS PENETRATION, PROGRAM CHANGES

THEFT OF DATA, SERVICES, EQUIPMENTTHEFT OF DATA, SERVICES, EQUIPMENT

TELECOMMUNICATIONS PROBLEMSTELECOMMUNICATIONS PROBLEMS

**

14.2

WHY SYSTEMS ARE VULNERABLEWHY SYSTEMS ARE VULNERABLE

• SYSTEM COMPLEXITYSYSTEM COMPLEXITY

• COMPUTERIZED PROCEDURES NOT COMPUTERIZED PROCEDURES NOT ALWAYS READ OALWAYS READ ORR AUDITEDAUDITED

• EXTENSIVE EFFEEXTENSIVE EFFECTCT OF DISASTEROF DISASTER

• UNAUTHORIZED UNAUTHORIZED ACCESS POSSIBLEACCESS POSSIBLE

**

14.3

VULNERABILITIESVULNERABILITIES

• RADIATION: Allows Recorders, Bugs to Tap SystemRADIATION: Allows Recorders, Bugs to Tap System• CROSSTALK: Can GCROSSTALK: Can Garble Dataarble Data

• HARDWARE: ImpropHARDWARE: Improperer Connections, Connections, Failure of Failure of ProtectiProtectionon CircuitsCircuits

• SOFTWARE: Failure SOFTWARE: Failure ofof Protection Features, Protection Features, Access Access Control, BouControl, Boundsnds ControlControl

• FILES: Subject to ThFILES: Subject to Theft,eft, Copying, Copying, Unauthorized Unauthorized AccessAccess

**

14.4

VULNERABILITIESVULNERABILITIES

• USER: Identification, Authentication, Subtle USER: Identification, Authentication, Subtle Software ModificationSoftware Modification

• PROGRAMMER: DisaPROGRAMMER: Disablesbles ProtectiveProtective Features; Reveals PrFeatures; Reveals Protectiveotective MeasuresMeasures

• MAINTENANCE STAFMAINTENANCE STAFF:F: DisablesDisables Hardware Hardware Devices; UDevices; Usesses Stand-aloneStand-alone Utilities Utilities

• OPERATOR: Doesn’t OPERATOR: Doesn’t Notify Supervisor, Notify Supervisor, Reveals Protective MReveals Protective Measureseasures

**

14.5

HACKERS & COMPUTER VIRUSES

HACKERS & COMPUTER VIRUSES

• HACKER: Person Gains Access to HACKER: Person Gains Access to Computer for Profit, Criminal Computer for Profit, Criminal Mischief, Personal PleasureMischief, Personal Pleasure

• COMPUTER VIRUS: Rouge Program; COMPUTER VIRUS: Rouge Program; Difficult to Detect; Spreads Rapidly; Difficult to Detect; Spreads Rapidly; Destroys Data; Disrupts Processing Destroys Data; Disrupts Processing & Memory& Memory

**14.6

ANTIVIRUS SOFTWAREANTIVIRUS SOFTWARE

• SOFTWARE TO DETECTSOFTWARE TO DETECT• ELIMINATE VIRUSESELIMINATE VIRUSES• ADVANCED VERSIONS RUN IN ADVANCED VERSIONS RUN IN

MEMORY TO PROTECT MEMORY TO PROTECT PROCESSING, GUARD AGAINST PROCESSING, GUARD AGAINST VIRUSES ON DISKS, AND ON VIRUSES ON DISKS, AND ON INCOMING NETWORK FILESINCOMING NETWORK FILES

**14.7

EFFECTS OF VIRUSESEFFECTS OF VIRUSES

62

41

38

30

24

23

20

9

4

3

0 10 20 30 40 50 60 70

LOSS OF PRODUCTIVITYLOSS OF PRODUCTIVITY

INTERFERENCE, LOCKUPINTERFERENCE, LOCKUP

CORRUPTED FILESCORRUPTED FILES

LOST DATALOST DATA

UNRELIABLE UNRELIABLE APPLICATIONSAPPLICATIONS

SYSTEM CRASHSYSTEM CRASH

LOSS OF CONFIDENCELOSS OF CONFIDENCE

LOST E-MAILLOST E-MAIL

CORRUPTED E-MAILCORRUPTED E-MAIL

THREAT OF JOB LOSSTHREAT OF JOB LOSS

PER CENT EFFECTEDPER CENT EFFECTED

BASED ON 600,000 MULTIPLE EFFECTS REPORTS

Source: Computerworld (1993)

14.8

CONCERNS FOR BUILDERS & USERS

CONCERNS FOR BUILDERS & USERS

DISASTERDISASTER

BREACH OF SECURITYBREACH OF SECURITY

ERRORSERRORS**

14.9

DISASTERDISASTER

• LOSS OF HARDWARE, SOFTWARE, LOSS OF HARDWARE, SOFTWARE, DATA BY FIRE, POWER FAILURE, DATA BY FIRE, POWER FAILURE, FLOOD OR OTHER CALAMITYFLOOD OR OTHER CALAMITY

FAULT-TOLERANT COMPUTER FAULT-TOLERANT COMPUTER SYSTEMS: BACKUP SYSTEMS TO SYSTEMS: BACKUP SYSTEMS TO PREVENT SYSTEM FAILURE PREVENT SYSTEM FAILURE (Particularly On-line Transaction (Particularly On-line Transaction Processing)Processing)

**14.10

SECURITYSECURITY

POLICIES, PROCEDURES, POLICIES, PROCEDURES, TECHNICAL MEASURES TO TECHNICAL MEASURES TO

PREVENT UNAUTHORIZED ACCESS, PREVENT UNAUTHORIZED ACCESS, ALTERATION, THEFT, PHYSICAL ALTERATION, THEFT, PHYSICAL

DAMAGE TO INFORMATION DAMAGE TO INFORMATION SYSTEMSSYSTEMS

**

14.11

WHERE ERRORS OCCURWHERE ERRORS OCCUR

• DATA PREPARATIONDATA PREPARATION• TRANSMISSIONTRANSMISSION• CONVERSIONCONVERSION• FORM COMPLETIONFORM COMPLETION• ON-LINE DATA ENTRYON-LINE DATA ENTRY• KEYPUNCHING; SCANNING; OTHER KEYPUNCHING; SCANNING; OTHER

INPUTSINPUTS

**14.12

WHERE ERRORS OCCURWHERE ERRORS OCCUR

• VALIDATION VALIDATION

• PROCESSING / FILE MAINTENANCEPROCESSING / FILE MAINTENANCE

• OUTPUTOUTPUT

• TRANSMISSIONTRANSMISSION

• DISTRIBUTIONDISTRIBUTION

**

14.13

SYSTEM QUALITY PROBLEMSSYSTEM QUALITY PROBLEMS

• SOFTWARE & DATASOFTWARE & DATA• BUGS: Program Code Defects or ErrorsBUGS: Program Code Defects or Errors• MAINTENANCE: Modifying a System in MAINTENANCE: Modifying a System in

Production Use; Can take up to 85% of Production Use; Can take up to 85% of Analysts’ TimeAnalysts’ Time

• DATA QUALITY PROBLEMS: Finding, DATA QUALITY PROBLEMS: Finding, Correcting Errors; Costly; TediousCorrecting Errors; Costly; Tedious

**

14.14

COST OF ERRORS DURING SYSTEMS DEVELOPMENT CYCLE

COST OF ERRORS DURING SYSTEMS DEVELOPMENT CYCLE

1.001.00

2.002.00

3.003.00

4.004.00

5.005.00

6.006.00

CO

ST

SC

OS

TS

ANALYSIS PROGRAMMING POSTIMPLEMENTATION ANALYSIS PROGRAMMING POSTIMPLEMENTATION & DESIGN CONVERSION & DESIGN CONVERSION

14.15

CREATING A CONTROL ENVIRONMENT

CREATING A CONTROL ENVIRONMENT

CONTROLS: Methods, Policies, CONTROLS: Methods, Policies, Procedures to Protect Assets; Procedures to Protect Assets; Accuracy & Reliability of Records; Accuracy & Reliability of Records; Adherence to Management StandardsAdherence to Management Standards

• GENERALGENERAL• APPLICATIONAPPLICATION

**

14.16

GENERAL CONTROLSGENERAL CONTROLS• IMPLEMENTATION: Audit System Development IMPLEMENTATION: Audit System Development

to Assure Proper Control, Managementto Assure Proper Control, Management• SOFTWARE: Ensure Security, Reliability of SOFTWARE: Ensure Security, Reliability of

SoftwareSoftware• PROGRAM SECURITY: Prevent Unauthorized PROGRAM SECURITY: Prevent Unauthorized

Changes to ProgramsChanges to Programs• HARDWARE: Ensure Physical Security, HARDWARE: Ensure Physical Security,

Performance of Computer HardwarePerformance of Computer Hardware

**

14.17

GENERAL CONTROLSGENERAL CONTROLS• COMPUTER OPERATIONS: Ensure Procedures COMPUTER OPERATIONS: Ensure Procedures

Consistently, Correctly Applied to Data Storage, Consistently, Correctly Applied to Data Storage, ProcessingProcessing

• DATA SECURITY: Ensure Data Disks, Tapes DATA SECURITY: Ensure Data Disks, Tapes Protected from Wrongful Access, Change, Protected from Wrongful Access, Change, DestructionDestruction

• ADMINISTRATIVE: Ensure Controls Properly ADMINISTRATIVE: Ensure Controls Properly Executed, EnforcedExecuted, Enforced

• SEGREGATION OF FUNCTIONS: Divide Tasks to SEGREGATION OF FUNCTIONS: Divide Tasks to Minimize RisksMinimize Risks

**

14.18

APPLICATION CONTROLSAPPLICATION CONTROLS

• INPUTINPUT

• PROCESSINGPROCESSING

• OUTPUTOUTPUT

**

14.19

INPUT CONTROLSINPUT CONTROLS

• INPUT AUTHORIZATION: Record, Monitor INPUT AUTHORIZATION: Record, Monitor Source DocumentsSource Documents

• DATA CONVERSION: Transcribe Data DATA CONVERSION: Transcribe Data Properly from one Form to AnotherProperly from one Form to Another

• BATCH CONTROL TOTALS: Count BATCH CONTROL TOTALS: Count Transactions Prior to and After ProcessingTransactions Prior to and After Processing

• EDIT CHECKS: Verify Input Data, Correct EDIT CHECKS: Verify Input Data, Correct ErrorsErrors

**

14.20

PROCESSING CONTROLSPROCESSING CONTROLS

ESTABLISH THAT DATA IS COMPLETE, ESTABLISH THAT DATA IS COMPLETE, ACCURATE DURING PROCESSINGACCURATE DURING PROCESSING

• RUN CONTROL TOTALS: Generate RUN CONTROL TOTALS: Generate Control Totals Before & After ProcessingControl Totals Before & After Processing

• COMPUTER MATCHING: Match Input Data COMPUTER MATCHING: Match Input Data to Master Filesto Master Files

**

14.21

OUTPUT CONTROLSOUTPUT CONTROLS

ESTABLISH THAT RESULTS ARE ESTABLISH THAT RESULTS ARE ACCURATE, COMPLETE, PROPERLY ACCURATE, COMPLETE, PROPERLY DISTRIBUTED DISTRIBUTED

• BALANCE INPUT, PROCESSING, OUTPUT BALANCE INPUT, PROCESSING, OUTPUT TOTALSTOTALS

• REVIEW PROCESSING LOGSREVIEW PROCESSING LOGS• ENSURE ONLY AUTHORIZED RECIPIENTS ENSURE ONLY AUTHORIZED RECIPIENTS

GET RESULTSGET RESULTS

**14.22

DEVELOPING A CONTROL STRUCTURE

DEVELOPING A CONTROL STRUCTURE

• COSTS: Can be Expensive to Build; COSTS: Can be Expensive to Build; Complicated to UseComplicated to Use

• BENEFITS: Reduces Expensive Errors, BENEFITS: Reduces Expensive Errors, Loss of Time, Resources, Good WillLoss of Time, Resources, Good Will

RISK ASSESSMENT: Determine RISK ASSESSMENT: Determine Frequency of Occurrence of Problem, Frequency of Occurrence of Problem, Cost, Damage if it Were to OccurCost, Damage if it Were to Occur

**

14.23

MIS AUDITMIS AUDIT

IDENTIFIES CONTROLS OF INFORMATION IDENTIFIES CONTROLS OF INFORMATION SYSTEMS, ASSESSES THEIR SYSTEMS, ASSESSES THEIR EFFECTIVENESSEFFECTIVENESS

• TRACE FLOW OF SAMPLE TRANSACTIONS; TRACE FLOW OF SAMPLE TRANSACTIONS; NOTE HOW CONTROLS WORKNOTE HOW CONTROLS WORK

• LIST, RANK WEAKNESSESLIST, RANK WEAKNESSES• ESTIMATE PROBABILITIES, IMPACTESTIMATE PROBABILITIES, IMPACT• REPORT TO MANAGEMENTREPORT TO MANAGEMENT

**

14.24

SOFTWARE QUALITY ASSURANCESOFTWARE QUALITY ASSURANCE

• USE PROVEN DEVELOPMENT METHODOLOGIESUSE PROVEN DEVELOPMENT METHODOLOGIES• RESOURCES ALLOCATION: How are Costs, Time, RESOURCES ALLOCATION: How are Costs, Time,

People Assigned During Development?People Assigned During Development?• SOFTWARE METRICS: Quantifiable System SOFTWARE METRICS: Quantifiable System

Measurements for Objective Software AssessmentMeasurements for Objective Software Assessment• TESTING: Walkthrough of Design Documentation, TESTING: Walkthrough of Design Documentation,

Debugging to Discover, Eliminate Defects, Data Debugging to Discover, Eliminate Defects, Data Quality Audit to Sample, Measure Accuracy, Quality Audit to Sample, Measure Accuracy, Completeness of DataCompleteness of Data

**

14.25

MANAGEMENT CHALLENGESMANAGEMENT CHALLENGES

• LARGE MULTI-USER NETWORKS LARGE MULTI-USER NETWORKS DIFFICULT TO SECUREDIFFICULT TO SECURE

• BALANCE DEGREE OF CONTROL, MAIN BALANCE DEGREE OF CONTROL, MAIN THREAT IS EXTERNALTHREAT IS EXTERNAL

• APPLY QUALITY ASSURANCE APPLY QUALITY ASSURANCE STANDARDSSTANDARDS

**

14.26