Systems Analysis, Design, Testing, and Implementation Vocabulary
System Life Cycle, Analysis & Documentation
Analysis Research Methods:
Questionnaires allow fast response collection, respondent anonymity, and low costs, but have low return rates and generic questions.
Interviews allow detailed one-to-one probing and answer evaluation, but are time-consuming and can introduce interviewer bias.
System Specification:
Defines general system requirements, identifies and justifies required hardware and software, and specifies system capabilities.
System Implementation Strategies:
Direct Changeover: Old system is immediately replaced. Benefits are immediate with lower staffing costs, but carries high risk of complete data loss if the system fails.
Parallel Running: Old and new systems operate together until verified. Safe with gradual staff training, but expensive due to running duplicate systems and staff.
Pilot Changeover: System is implemented branch by branch. Limits failure risk to one branch and makes changeover easier to manage.
Phased Implementation: System is introduced one process or module at a time.
Testing Strategies & Data Types:
Test Strategy: High-level developer guidelines explaining testing methodology, techniques, and module scope before test execution.
Test Plan: Operational plan detailing specific test objectives, schedules, assigned testers, test data, expected outcomes, and remedial actions.
Normal Test Data: Typical valid data within acceptable range limits.
Extreme Test Data: Valid data situated precisely on the boundary of acceptability (for example, and for a range of to ).
Abnormal Test Data: Data outside acceptable limits or of incorrect data types.
System Documentation:
Technical Documentation: Assists programmers and analysts in maintaining, updating, or repairing software (contains algorithms, file structures, flowcharts, variable lists, validation routines, and hardware/software requirements).
User Documentation: Assists end-users in operating software (contains user guides, installation steps, error messages, FAQs, and troubleshooting guides).
ePublications: Digital documentation featuring embedded multimedia, internal/external hyperlinks, searchability, auto-page turning, and lower distribution costs.
Data Verification, Validation & Layout Design
Data Verification Methods:
Visual Verification: Checking entered data against the original paper source document to prevent copying errors.
Double Data Entry: Entering data twice by different operators to ensure exact matching.
Data Validation Routines:
Format Check: Verifies correct pattern (for example,
dd/mm/yyyyfor dates).Range Check: Verifies data falls within lower and upper bounds (for example, month range to ).
Length Check: Verifies exact character counts.
Type / Character Check: Ensures data contains only valid character types (for example, numeric integers only).
Presence Check: Ensures a field is not left blank or null.
Check Digit: An extra calculated digit added to verify code integrity.
Data Encoding & Design Features:
Coding Data: Shortens data entries (for example, country codes like NZL for New Zealand or model codes like H/P/E) to save storage space, speed up data entry, and enable faster searching.
Form and Report Design: Requires clear fonts, sufficient contrast, logical question flow, clear headings/subheadings, and appropriate use of white space.
Recognition Systems & Direct Data Entry
Direct Data Entry (DDE) Technologies:
MICR (Magnetic Ink Character Recognition): Reads magnetic ink on cheques; human-readable, resistant to fraud and photocopies.
OMR (Optical Mark Recognition): Reads positions of marks in designated areas (for example, multiple-choice exam sheets, lottery tickets).
OCR (Optical Character Recognition): Converts scanned text images into editable electronic characters (used in document conversion and number plate recognition).
RFID (Radio Frequency Identification): Uses radio signals between reader antennas and microchips; reads contactless data through barriers without direct line-of-sight and processes multiple tags simultaneously.
Barcodes & QR Codes: Barcodes require direct optical line-of-sight. QR codes store more data in less physical space, are read from multiple angles, and link directly to digital media.
Biometric Systems:
Types: Fingerprints, handprints, iris scans, retina scans, facial recognition, voice recognition, vein geometry.
Effectiveness: Highly secure as physical traits are unique, impossible to forget/lose, and require physical presence; however, hardware is costly, setup is time-consuming, false reads occur if injured/dirty, and data cannot be reset if compromised.
Sensors, Microprocessor Control & Robotics
Microprocessor Control Loop:
Sensors continuously send physical readings (for example, temperature, light, proximity, timer) to the microprocessor.
Microprocessor compares sensor data against pre-set stored values.
If readings diverge from target values, the microprocessor transmits control signals to an actuator.
Actuator operates physical output devices (for example, switching heaters/ovens on/off, opening/closing car park barriers, applying automated vehicle brakes).
Process repeats continuously in real time.
Industrial & Agricultural Robotics:
Benefits: Operates continuously (), operates safely in hazardous or sterile environments, delivers superior accuracy and output consistency, and lowers long-term production costs.
Drawbacks: High capital purchase and maintenance costs, causes worker redundancy, leads to skill loss (de-skilling), and causes total process shutdown during software or hardware failures.
Computer Modelling & Simulation
Applications & Purpose:
Used for structural testing (bridges), weather forecasting, traffic junction timing, and flight/vehicle simulations.
Key Benefits:
Safer than real-life testing (avoids human injury or bridge collapse during extreme tests).
Saves time and financial resources compared to physical prototyping.
Evaluates complex "what-if" scenarios across multiple variables rapidly.
Drawbacks:
High software development costs; accuracy is entirely dependent on programmer input and cannot replicate every real-world variable.
Expert Systems
Primary Components:
User Interface: Displays questions and captures user inputs (commonly Y/N responses).
Knowledge Base: Repository of domain facts and rules accumulated from human experts.
Rules Base: Structured set of logical conditional criteria applied to data.
Inference Engine: Reasoning processing engine that searches the knowledge base using the rules base to deduce new facts.
Explanation System: Details step-by-step logic used to reach conclusions.
Applications: Medical disease diagnosis, oil/mineral prospecting, financial/tax advice, car engine fault diagnosis, strategy games, career recommendations.
Sources of Incorrect Diagnosis: Incorrect data pre-loaded into the knowledge base, user entering false symptoms, or novel/unstored medical conditions.
Banking, Shopping & Online Services
Automated Teller Machines (ATMs) & Banking:
ATM Processing: Reads debit card chip via PIN pad/reader, verifies account status and PIN against bank database, scans cheque using MICR/OCR, checks funds, and dispenses receipts/cash.
Internet Banking vs In-Branch: Internet banking offers access, eliminates travel, and provides better rates; in-branch banking provides face-to-face assistance and cash handling, but involves queuing and limited opening hours.
Retail Systems (POS & EFTPOS):
Automated Stock Control: Barcode scanned at Point of Sale (POS) -> database queried -> item stock reduced -> if stock level reaches or drops below re-order threshold, an automated re-order signal is dispatched to warehouse systems.
Contactless EFTPOS Processing: Terminal checks transaction limit -> reads card chip via RFID/NFC -> contacts customer's bank to verify card and funds -> transmits authorization code -> transfers funds -> updates merchant terminal.
System Life Cycle, Analysis & Documentation
Analysis Research Methods:
Questionnaires allow fast response collection, respondent anonymity, and low costs, but suffer from low return rates, generic questions, and inability to observe body language.
Interviews allow detailed one-to-one probing and answer evaluation, but are time-consuming and can introduce interviewer bias.
Observation involves watching staff use the current system to identify inputs, processes, outputs, and errors, though the Hawthorne effect may reduce reliability.
System Analysis & Specification:
Identifies inputs, processing, outputs, data flow, and existing problems of the current system.
Defines general system requirements, identifies and justifies required hardware and software, and specifies required system capabilities.
System Implementation Strategies:
Direct Changeover: Old system is immediately replaced. Benefits are immediate with lower staffing costs and single-system operation, but carries high risk of complete data loss if the system fails.
Parallel Running: Old and new systems operate simultaneously until verified. Safe with gradual staff training and backup availability, but expensive due to duplicate hardware, software, and staffing requirements.
Pilot Changeover: System is implemented branch by branch. Limits failure risk to one branch, making changeover easier to manage and staff training localized.
Phased Implementation: System is introduced one process or module at a time.
Testing Strategies, Plans & Data Types:
Test Strategy: High-level developer guidelines explaining testing methodology, techniques, and module scope before test execution.
Test Plan: Operational plan detailing specific test objectives, schedules, assigned testers, test data, expected outcomes, actual outcomes, and remedial actions.
Normal Test Data: Typical valid data within acceptable range limits (for example, for a range of to ).
Extreme Test Data: Valid data situated precisely on the boundary of acceptability (for example, and for a range of to ).
Abnormal Test Data: Invalid data outside acceptable limits or of incorrect data types (for example, numbers below , above , or non-numeric characters).
System Evaluation:
Compares the final solution against original user requirements to verify all objectives are met.
Identifies limitations or errors arising during testing and implementation.
Evaluates user feedback (such as beta testing responses) and measures task completion efficiency compared to the old system.
System Documentation:
Technical Documentation: Assists programmers and analysts in maintaining, updating, or repairing software (contains algorithms, file structures, program listings, flowcharts, variable lists, validation routines, and hardware/software requirements).
User Documentation: Assists end-users in operating software and troubleshooting (contains user guides, installation steps, error messages, FAQs, and troubleshooting guides).
ePublications: Digital documentation featuring embedded multimedia, internal/external hyperlinks, searchability, auto-page turning, and lower production costs compared to printed booklets.
Data Verification, Validation & Layout Design
Data Verification Methods:
Visual Verification: Checking entered data against the original paper source document to prevent copying or transcription errors.
Double Data Entry: Entering data twice by different operators to ensure exact matching via system comparison.
Data Validation Routines:
Format Check: Verifies correct pattern (for example,
dd/mm/yyyyfor dates).Range Check: Verifies data falls within lower and upper bounds (for example, month range to ).
Length Check: Verifies exact character counts (for example, exactly characters for a barcode).
Type / Character Check: Ensures data contains only valid character types (for example, numeric integers only).
Presence Check: Ensures a field is not left blank or null.
Check Digit: An extra calculated digit added to verify code integrity.
Data Encoding & Design Features:
Coding Data: Shortens data entries (for example, country codes like NZL for New Zealand or model codes like H/P/E) to save storage space, speed up data entry, reduce errors, and enable faster searching.
Form and Report Design: Requires clear fonts, sufficient contrast, logical question flow, clear headings/subheadings, input masks, drop-down lists/radio buttons, and appropriate use of white space.
Recognition Systems, Direct Data Entry & Malware
Direct Data Entry (DDE) Technologies:
MICR (Magnetic Ink Character Recognition): Reads magnetic ink on cheques; human-readable, highly secure, and resistant to fraud or photocopies.
OMR (Optical Mark Recognition): Reads positions of marks in designated areas (for example, multiple-choice exam sheets, lottery tickets).
OCR (Optical Character Recognition): Converts scanned text images into editable electronic characters (used in document conversion and Automated Number Plate Recognition).
RFID (Radio Frequency Identification): Uses radio signals between reader antennas and microchips; reads contactless data through barriers without direct line-of-sight and processes multiple tags simultaneously.
Barcodes & QR Codes: Barcodes require direct optical line-of-sight and read one item at a time. QR codes store more data in less space, are read from multiple angles, and link directly to digital media.
Biometric Systems:
Types: Fingerprints, handprints, iris scans, retina scans, facial recognition, voice recognition, vein geometry.
Effectiveness: Highly secure as physical traits are unique, impossible to lose or forget, and require physical presence; however, hardware is costly, setup is time-consuming, false reads occur if injured or dirty, and data cannot be reset if compromised.
Malware & Security Risks:
Computer Viruses: Malicious software code that attaches to files and replicates itself across systems.
Effects: Fills hard drive space, slows processing, causes random reboots/pop-ups, deletes files, or disables anti-virus programs.
Prevention: Installing and regularly updating anti-virus software, scanning attachments prior to download, and avoiding untrusted emails.
Sensors, Microprocessor Control & Robotics
Microprocessor Control Loop:
Sensors continuously send physical readings (for example, temperature, light, proximity, pressure) to the microprocessor.
Microprocessor compares sensor data against pre-set stored values.
If readings diverge from target values, the microprocessor transmits control signals to an actuator.
Actuator operates physical output devices (for example, switching heaters on/off, operating car park barriers, applying automated vehicle brakes).
Process repeats continuously in real time.
Industrial & Agricultural Robotics:
Benefits: Operates continuously (), operates safely in hazardous or sterile environments, delivers superior accuracy and output consistency, and lowers long-term production costs.
Drawbacks: High capital purchase and maintenance costs, causes worker redundancy, leads to skill loss (de-skilling), and causes total process shutdown during software or hardware failures.
Computer Modelling & Simulation
Applications & Purpose:
Used for structural testing (bridges), weather forecasting, traffic junction timing, flight/vehicle simulations, and global warming predictions.
Key Benefits:
Safer than real-life testing (avoids human injury or structural collapse during extreme test scenarios).
Saves time and financial resources compared to physical prototyping.
Evaluates complex "what-if" scenarios across multiple variables rapidly.
Drawbacks:
High software development costs; accuracy is entirely dependent on programmer input and cannot replicate every real-world variable.
Expert Systems
Primary Components:
User Interface: Displays questions and captures user inputs (commonly Y/N responses).
Knowledge Base: Repository of domain facts and rules accumulated from human experts.
Rules Base: Structured set of logical conditional criteria applied to data.
Inference Engine: Reasoning processing engine that searches the knowledge base using the rules base to deduce new facts.
Explanation System: Details step-by-step logic used to reach conclusions.
Applications:
Medical disease diagnosis, oil/mineral prospecting, financial/tax advice, car engine fault diagnosis, strategy games, and career recommendations.
Sources of Incorrect Diagnosis:
Incorrect data pre-loaded into the knowledge base, user entering false symptoms, or novel/unstored medical conditions.
Banking, Shopping & Online Services
Automated Teller Machines (ATMs) & Banking:
ATM Processing: Reads debit card chip via PIN pad/reader, verifies account status and PIN against bank database, scans cheque using MICR/OCR, checks funds, and dispenses receipts/cash.
Internet Banking vs In-Branch: Internet banking offers access, eliminates travel, and provides better rates; in-branch banking provides face-to-face assistance and cash handling, but involves queuing and limited opening hours.
Retail Systems (POS & EFTPOS):
Automated Stock Control: Barcode scanned at Point of Sale (POS) -> database queried -> item stock reduced -> if stock level reaches or drops below re-order threshold, an automated re-order signal is dispatched to warehouse systems.
Contactless EFTPOS Processing: Terminal checks transaction limit -> reads card chip via RFID/NFC -> contacts customer's bank to verify card and funds -> transmits authorization code -> transfers funds -> updates merchant terminal.
Online Shopping & Booking Systems:
Features: availability, virtual shopping baskets/checkout, global customer reach, automated order receipts/e-tickets, and immediate seat or item availability updates.