Computer Science

Computer Science

1. Computer systems

   • Input>Process>Output
     • Storage

2. Reliability: How long it is likely to run before breaking

   • Measured in:
     • MTBF
       • Mean time between failure: The average time before a system breaks
     • System availability
       • The percentage of time the system is running for
   • Can make a system more reliable by
     • Hardware redundancy
       • When you have a spare piece of equipment to replace something that breaks
     • RAID
       • Redundant array of independent disks: When you have spare hard drives that come into play when one breaks
     • Disaster recovery
       • A plan that a business has in case something happens to their systems

3. Professional standards

   • System development lifecycle
     • Planning
     • Analysis
     • Design
     • Implementation
     • Maintenance
   • Standards of coding
     • Sections should be intended
     • Comments should explain the part of code
     • Variables should have meaningful names
   • Documentation
     • Flow charts should follow rules
     • Logic diagrams should use correct symbols
   • Health and safety
     • Standardised safety laws and rules
     • Display screen regulations add extra laws for people working in IT