Topic 7 - Control systems [HL]

Evaluation of control systems

This section looks at the advantages and disadvantages of control systems, including its moral and ethical implications.

This section is evaluates different systems. The first evaluation is for control systems in general and is followed by a comparison of centralized and distributed systems. Lastly the more specific implications on prisoner tagging, surveillance, CCTV and safety systems are discussed.



  • Computers can respond very rapidly to change.
  • Systems can run 24 hours a day, 365 days a year.
  • Control systems can operate in places that humans would find dangerous or awkward.
  • Outputs are consistent and error free.
  • Computers can process data quickly and machines can operate faster than humans.


  • The software for the control system is specialized and may cost a lot of money to develop
  • If the computer malfunctions the system will not work
  • If there is a power cut the system will not work
  • The computer can’t react to unexpected events like a human could. It can only respond in the way it has been programmed to.
  • It can cause some concern if total control for a system and the decisions are handed over to a computer.

Centralized vs. distributed systems

Centralized systems Distributed system
  • Single point of control
  • Access to all resources at one point
  • Relatively easy implementation
  • Higher reliability through multiple points of failure
  • Lower cost
  • Speed
  • Scalability
  • Data and resource sharing
  • Flexibility
  • Improved communication
  • Single point of failure
  • Potentially higher cost
  • Less power
  • Less flexibility
  • Harder to maintain
  • Less accessibility
  • Dependance on network bandwidth
  • More complex software
  • Security risks

Tagging prisioners


  • Government no longer needs to house or feed the prisoner in a prison so there is a cost saving.
  • Can be safer for the community as people who may not normally be sent to prison can be effectively monitored.
  • Families who rely on convicted person can continue to live with them and receive financial/emotional support.
  • There may be improved rehabilitation as offenders are not removed from society and put in a “criminal” environment.


  • Risk of devices being removed and prisoners offending.
  • Does not necessarily prevent any future crimes
  • System is expensive to set up.
  • System may not be reliable and there may be areas where the system does not cover.
  • Extra people are required to monitor and intervene when there are problems.
  • There may be privacy issues.
  • The security of the system is important as any hacking would reveal sensitive data



  • Preventing crime and even terrorism (NSA)
  • Potentially increased safety
  • More evidence for finding criminals
  • Superiors can ensure productivity, e.g. the boss tracking his employees, or the teacher ensuring that students work


  • Privacy concerns -> collection of user data from normal people, even if they don’t do anything (be it crime, or being unproductive)
  • Chance of misuse/abuse
  • Personal information is very sensitive and holds power -> can be used for criminal actions as blackmailing or even murder



  • Helps looking at different places at the same time
  • Helps maintain security
  • Video clips can be used as evidence for investigations
  • Lead to reduction in damages such as vandalism or theft
  • Can be conveniently monitored over the internet


  • Too many can intrude a person’s privacy
  • Doesn’t necessarily prevent crime
  • Misuse of captured pictures from public surveillance
  • Can be dangerous in the wrong hands, e.g. stalkers
  • Surveillance cameras can be hacked, which leads to misuse

Improved safety systems


  • Improve safety for users, e.g. passengers in a car
  • Can save lives
  • May open more job opportunities as skilled workers are needed for maintainance


  • Subject to technical failure, e.g. bugs
  • More complex and harder to maintain requires skilled workers, e.g. a car mechanic may not be able to repair the car, needing an electrical engineer