The system key features:

• To limit the potentially harmful effects of the actions of the person doing the work by specifying safety precautions and setting limits to the duration and extent of the work.
  
  
• Allows those responsible for overall site safety to be aware of the various hazardous activities and to take a systematic overview which identifies interactions and allows priorities to be set for conflicting work tasks.
  
  
• Encourage formal and careful attention to safe systems of working, by requiring the signature of specified individuals who must confirm that all hazards have been identified and effective precautions taken.
  
  
• Encourage those responsible for overall site safety to plan the carrying out of tasks so that minimal inconvenience and interference is caused to other tasks or production.