Chapter 1 - System Fundamentals Flashcards
(29 cards)
Purpose of a new system (4)
Increase productivity
Increase quality of output
Minimize costs
Reduce errors/flaws of existing system
Potential organizational issues of new system (4)
Lack of guiding organizational business strategies
Lack of stakeholder and end-user participation
Lack of attention to required training.
Lack of attention to design of tasks and jobs, allocation of information system tasks, and overall usability of system.
What is a feasibility report (6)
Used to decide whether proposed system should be implemented.
Evaluates system’s potential based on criteria:
Technical:
Economical
Legal
Operational
Scheduling criteria
Explain each criteria of feasibility report (5)
Technical: existing technology sufficient to support proposed system?
Economic: Cost effective?
Legal: conflicts between proposed system and laws?
Operational: existing practices/procedures sufficient to support operation + maintenance of new system?
Schedule: How long it takes to implement?
Compatibility issues of using legacy system to change system (2)
Old system’s data cannot convert to newer formats, or application cannot be upgraded.
Compatibility issues of business merger to change system (2)
Involves: combining two or more business entities.
Software may be incompatible so cannot operate on same computer or on computers linked by a computer network.
Difficulties in changing system (12)
User resistance: consumers don’t want change.
Omitted features: features may disappear from old system.
Performance issues: new system may be slower.
Incompatibility: new system may be incompatible with other systems that were previously in conjunction with old system.
Data loss: Data might be lost during migration process.
Cost: new software = costly
Different ways to switch system
Direct changeover
Parallel changeover
Pilot system
Phased conversion
Explain direct changeover
Unplug old, plug in new system simultaneously.
Ads: Immediate availability of new system.
Dads: No time to work out bugs, no backups in case of failure, abruptness hard on users.
Explain Parallel changeover
Run both systems simultaneously, inputting data into both systems.
Ads: Compare output of old and new system to verify and check for errors, backup available in case of failure, users can compare and give feedback.
Dads: costly to run both.
Explain Pilot system
New system implemented to small part of an org. and expanded to rest after verify it is correct.
Ads: all features tested full adoption, only small area affected.
Dads: no backup in case of failure for the small area.
Explain Phased conversion
Introduce features of new system gradually by replacing or adding one feature at a time.
Ads: users can adapt incrementally, low risk, backup available in case of failure.
Dads: takes more time to train, system change is long.
Problems of Data migration (5)
New system cannot read file format of old.
organization difference (e.g. collection vs. list)
Data may be valid in old, but rejected in new.
Data lost during migration.
Difference in conventions: (usually occurs during country change) (E.g. currency, date format, language…)
Explain Legacy system
System or applications no longer supported by their patent company, or unavailable for purchase.
E.g. nintendo 64
Local vs. Remote software
Local: runs on computer directly, depends on OS. Consumes resources locally. E.g. notes app from Apple. Updates are visible (manual or automatic).
Remote: A.k.a SaaS. Accessed through web browser. E.g. google docs, gmail. Any computer with browser can access, updates generally invisible.
Advantage and Disadvantage of SaaS
SaaS: delivery method where software and data hosted by remote center.
Ads: accessible from anywhere, cost-effective: only need browser, easy to add users, pay as you go: subscription model.
Dads: availability depends on provider, must abide to provider’s compliance standards, if data corrupted limited resources, lower performance compared to software running on local machine.
Types of software testing
Static testing: examine documentation, specs, plans. Verifies if planned system is right. Synonymous with verification.
Dynamic testing: testing during software running: code executed to check output is correct.
Alpha testing: internal team tests software.
Beta testing: small group of intended end-users test. Feedback collected, bugs fixed.
Black box testing: Test software without seeing code (e.g. use every feature on Word to see if they work as intended)
White box testing: conducted by software engineer, test code.
User-acceptance testing: finished system tested by end-users.
Types of user documentation
User documentation required when new system or software implemented to help users understand features.
Manuals
Online resources
Help file
Explain Verification and Validation in data input
Validation: evaluate data input, check it follows appropriate specs and is in reasonable limites (e.g. range check, type check…)
Verification: ensures data input is same as original source data (e.g. double keying…)
Different types of support
Email support
Embedded assistance
FAQs
Live chat session
Online portal
Remote desktop connections
How are staff and user trained
Online class, formal class, self-instruction.
Methods to prevent data loss
Failover systems: backup system with identical data and capabilities in case of failure. Common to places with frequent natural disasters.
Redundancy: having multiple identical resources to be used if primary resource fails.
Removable media: update removable hard drives with data for safe-keeping.
Off-site storage: store data in remote location (iCloud, different building).
Security: measures to protect physical storage devices from theft, damage.
Common causes of data
Hardware/software malfunction: external factors corrupting data.
Human error: accidental deletion or unplug during process.
Malicious software: software made to destroy or steal data.
Natural disasters: causes physical damage to physical storage. Power cuts.
Role of CPU
Brain of computer, processes instruction from programs and peripherals.
