This system lets the users to track their position with GPS and/or NFC, automatically set up an alarm timer on a period appropriate for the current hazardous location and trigger a sequence of actions when the timer expires or the position remains unchanged.
The system consists of a mobile application running on mobile phones communicating to the server via HTTP protocol. To achieve high reliability two servers are executing the same tasks and a worker’s state is monitored on both servers and on the mobile phone.