Systems Unit Flashcards
Planning - What is the context?
The current situation and problem
Planning - extent and limitations
Figuring out the exact features needed and not to save time
Planning - organisational issues
The legistics/ infrastructure that needs to be sorted out
For example, a school attendance system might be used on a sports
field, requiring a system that can run in a wireless network using
portable devices.
Planning - underlying technologies
What the code has to work with/ what is there
Examples: OS, hardware, wifi speed etc.
What is change management?
Making sure that the new code will work on the old infrastructure with easy turnover
Example problems include: old hardware not being good enough to run system
Compatibility - Legacy
The need to support old standards, if that is what is being used.
Compatibility - business mergers
During business mergers, the data is often stored in different formats. Which can result in data loss or recovery.
Compatbility - compatibility
the issue of whether two computer systems
can function together successfully
Implimentation - Remote (not on device) advantages
- Centralised (easy to update)
- Use thin clients (on device) meaning can run on large amount of devices with limited power
Implimentation -Local advantages`
Local is always faster than remote and could be used offline
What is software as a service?
“renting” software on a temporary basis,
rather than selling the software or the
software license.
Example: itunes being free but need to buy content
What is a direct changeover?
Immediate changeover of software, the old software is discarded.
What is a phased implimentation (change over)?
A gradual process where the use of the old system is reduced and use of the new system is increased
What is parallel running (changeover)?
When both system systems are running and supported simultaniously.
- Safest
- Double the work
Data migration - data structures problems
Incompatiblity between types of data from the old system.
For example an SQL database might not be able to run on an outdated version of java
Data migration - currency
Currency will not always be the same in a global system and might need to be converted or supported.
Types of testing
User acceptance (final step/client tesing), debugging (first/continous while programming), beta (small group tesing)
User documentation problems
- normal users are not interested in figuring out
- Bad documentation may cause frustrationand decreased productivity
- Software should conform to the norms, young programmers will try to make flashy unintuative software
Types of user training
Formal classes (face to face), online training (youtube/zooms), multimedia presentation (powerpoints)
Training - advantages of formal classes
Management can be sure everyone has the proper training
Training - online training advantages
Users can stay seated while they learn from anywhere
Training - multimedia presentations advantages
More enjoyable than a simple text manual
2 Causes of data loss
- Malicious
- natural disaster
Example consequences of data loss
no bank records => no money
incorrect password => you cannot log in, no access
incorrect birth date => can affect credit rating, medical treatment
lost purchase order => items do not get delivered
3 data loss prevention methods
Failover (2nd backup server), redundancy (batckups stored in a safe place), removeable media (less frequent backups to a seperate site).
What is a release?
A whole new version, which might need to be reinstalled.
Example windows 7 => windows 8
What is an update?
Small impovements or fixes often automatic
What is a patch?
Very small bug fixes, usually automatic
SLDC Step 1:
Requirements and analysis
SLDC Step 2:
Design
SLDC Step 3:
Implementation
SLDC Step 4:
Testing/operation
SLDC Step 5:
Maintanance
