Method for Periodically Determining Time-to-Service

A method for periodically determining time-to-service of a submersible machine, wherein the machine for each periodically determination is associated with a calendar-time-to-service and a running-time-to-service, wherein the running-time-to-service is based on a running-time-left before service is required and a historic utilization rate of the machine,

• wherein the method is characterized by performing the following steps during each periodically determination:
• updating at least one of said calendar-time-to-service and said running-time-to-service, by:
• monitoring a first operational parameter (OP1) having effect on the calendar-time-to-service,
• comparing the first operational parameter value (OP1) with a default first operational parameter value (D-OP1), wherein a deviation in said comparison provides a calendar-time adjustment-factor that is proportional to the deviation,
• adjusting the calendar-time-to-service based on said calendar-time adjustment-factor, and
• monitoring a second operational parameter (OP2) having effect on the running-time-left of the machine,
• comparing the second operational parameter value (OP2) with a default second operational parameter value (D-OP2), wherein a deviation in said comparison provides a running-time adjustment-factor that is proportional to the deviation,
• adjusting the running-time-to-service based on said running-time adjustment-factor, and
• thereafter setting the time-to-service of the machine equal to the shortest of the calendar-time-to-service and the running-time-to-service.