A method of operating an industrial plant having processing units (311a-311f) that includes a wireless network including a network server, at least one router (325, 330), and a plurality of workers (1, 2, 3) including a first worker, comprising: providing a first handheld computing device having a wireless transceiver, a display and a processor programmed to implement a location-based service algorithm stored in non-transitory machine readable storage to the first worker, said location-based service algorithm implementing: obtaining location information that identifies a physical location for said first worker, and adding said location information to wireless transmissions of information by said first worker to others (2, 3) of said plurality of workers (1, 2, 3) and/or to said network server, said first handheld computing device downloading specific tasks and instructions from the network server and wirelessly receiving plant information provided by the network server that is a function of said physical location, plant information comprising a list of processing units (311a-311f) determined to be within a preprogrammed maximum distance of the first worker's physical location, said location-based service algorithm providing a task list for the first worker when the first worker is within a preprogrammed maximum distance of one or more predetermined locations in the plant, each predetermined location being that of a processing unit (311a-311f) at which a task is to be executed, whereby said handheld computing device automatically displays on the display a location of tasks to be executed by said first worker relative to said physical location, and said first worker performing at least one action guided at least in part by said instructions. providing a first handheld computing device having a wireless transceiver, a display and a processor programmed to implement a location-based service algorithm stored in non-transitory machine readable storage to the first worker, said location-based service algorithm implementing: obtaining location information that identifies a physical location for said first worker, and adding said location information to wireless transmissions of information by said first worker to others (2, 3) of said plurality of workers (1, 2, 3) and/or to said network server, obtaining location information that identifies a physical location for said first worker, and adding said location information to wireless transmissions of information by said first worker to others (2, 3) of said plurality of workers (1, 2, 3) and/or to said network server, said first handheld computing device downloading specific tasks and instructions from the network server and wirelessly receiving plant information provided by the network server that is a function of said physical location, plant information comprising a list of processing units (311a-311f) determined to be within a preprogrammed maximum distance of the first worker's physical location, said location-based service algorithm providing a task list for the first worker when the first worker is within a preprogrammed maximum distance of one or more predetermined locations in the plant, each predetermined location being that of a processing unit (311a-311f) at which a task is to be executed, whereby said handheld computing device automatically displays on the display a location of tasks to be executed by said first worker relative to said physical location, and said first worker performing at least one action guided at least in part by said instructions.