Measurements are recorded against Equipment Object parameters, in IFS/Service and Maintenance.
Measurement values can be used by the maintenance planning system - Preventive Maintenance and Condition Based Maintenance. The readings can also be used for analytical purposes- to track the performance of equipment, look for trends in usage, etc.
Each measurement has a Measurement Type. When a reading is entered, it is validated - depending upon the validation, it is given the relevant measurement type. If the reading is invalid and requires correction - the outcome of the correction process will include changes to the measurement type. Only Valid readings are used by the system for maintenance planning purposes.
|
Measurement Type |
Usage |
Description |
|
Recorded Reading |
Valid reading |
The reading taken is valid, both technically (the value/registration date, and their relationship to other readings) and objectively (the reading has been accepted as usable or relevant) |
|
After Meter Change |
Technical reading |
The reading that has been taken at the conclusion of a change of a meter. When a meter has been changed, two readings are required - one from the old meter, before removal, another from the new meter, on meter start up. The new meter value is recorded as a type ‘After Meter Change’. If the meter is recording an Accumulated type parameter, this will ensure that the total value for the parameter is not affected by the meter change process. It is assumed that there is no increment in value between the values of 'Before Meter Change' and 'After Meter Change'. |
|
Meter Rollover |
Technical reading |
When an incrementing meter is used that has a finite reading scale, if the total accumulated value exceeds the maximum scale value, the meter will typically ’roll over’ - starting again at zero. If such an event has occurred, the next reading will usually be lower than the previous value. E.g. roll over at 100 000. Last reading - 95 000. New reading - 5 000. The actual total value is 105 000 - this is not visible on the meter, due to the roll over, but by indicating to the system that the meter has rolled over, all readings subsequent of this event will be cumulative on the roll over value. A record is made in the measurement history of the measurement type ‘Meter rollover’ to indicate that the event occurred, but it is dated with an estimated date, as the actual rollover date will not be known. For this reason, the reading is not used for analytical purposes. |
|
Before Meter Change |
Valid reading |
The reading that has been taken at the start of a change of a meter. Two readings are taken - the old meter last reading, and new meter, initial reading. Only one of these is required, for analytical purposes, so the old meter last reading is recorded, to ensure the total increment can be calculated, for Accumulated measurements, but is not used for maintenance planning purposes. |
|
Meter Setup |
Technical reading |
The reading used to record the meter ID and/or the meter start value - when a meter is setup. For a new parameter, the ID may be recorded, before any meter reading is taken. For an existing meter, that has not got an ID recorded - this is used when only the meter ID is being added to the record. |
|
Preliminary Reading |
Invalid reading |
The reading taken that is considered invalid. When a reading is entered, it is validated against the parameter attributes, and against other readings. It may fail validation for one or more of a number of reasons. Examples are - for an accumulated type parameter - the value is lower than the previous reading, the reading is higher than the declared meter roll-over value. It may be that the reading is actually incorrect - or it may be correct, but only in the context of another action - e.g. reporting a meter change. A Preliminary reading will require correction - it should not be left as a Preliminary reading. All readings dated to follow on from a Preliminary Reading will also be classified as Preliminary, as it is not possible to validate them, until the first preliminary reading is corrected. |
|
Incorrect Reading |
Invalid reading |
The reading taken has been judged to be invalid, and incorrect. Incorrect readings are not deleted - they are retained, but classified as incorrect, so that it is clear what readings have been taken, by whom, and when. This potentially assists with fault finding and auditing.. |
A meter may have an identity. It is possible that a meter is also registered as an Equipment Object, but typically, it is not an individual object. The meter identity may be generic (make/model of meter), or may be unique (serial number). The measurement system supports the recording of a meter ID, to assist with the tracking of meters, the detection/prevention of fraud and to detect meter changes.
The test point/parameter on a serial or functional object has an attribute ‘Meter ID Required’. This is set to either ‘Mandatory’, ‘Optional’ or ‘Not Used’. Depending upon the setting of this attribute, when a reading is taken, and when meters are changed, the meter ID will either be required, be optional to enter, or the meter ID field will be inactive.
Once a Meter ID has been set against a parameter, it is automatically recorded against each subsequent reading. It can then only be changed via the Meter Change process.
When a new test point/parameter is created, it is potentially a representation of a physical meter. The meter may already exist, or may be installed (in new or used condition) at the same time as the system record is created.
During the lifetime of the equipment, a meter may fail and need replacing, or a replacement meter may be fitted with enhanced capabilities.
The measurement reading process therefore has to be able to deal with these situations - either in a planned way (e.g. the technician is replacing the meter, and needs to report this to the system at the same time), or in reaction to a change having already happened (e.g. the technician takes a reading and discovers that the meter has been changed by someone else, unknown to them, since the previous reading)
Meter setup and change is supported by two functions
The Setup/Change Meter dialog is used to support initial meter setup, or initial parameter setup. Its purpose is to allow input of a start value (for a parameter that has no existing readings) and a meter ID, where this is known. It also supports the reporting of a meter ID at a later date - once readings are in progress - where only the ID is to be reported (e.g. paper records exist of the meter IDs, these now need to be entered into the system against existing parameters)
The dialog is also used to support meter changes, once measurements have commenced. The details of the new meter are entered (start value, meter ID if relevant, changeover date) and the final reading value is taken from the old meter. This allows for the two readings and the meter change details to all be entered in one dialog.
The Manage Preliminary Reading assistant is used for readings that have failed validation. If a meter has been changed without taking a measurement/recording the change, the following reading might be set as incorrect. E.g. the previous reading was 8500, the new reading is 150 - the parameter is of an Accumulated type, so the new reading should have been greater than 8500. One of the options in correcting the reading, via the assistant, is to report a meter change. In this example - the meter may have been part of some ancillary equipment - a contractor replaced the equipment - the meter built into it has therefore changed.
Meters used for accumulated type parameters may have a maximum limit for their reading. An example is a car odometer - traditionally these ‘roll-over’ at 99 999 km or miles - so 101 500 km would display as 001500 km, with no indication that the meter has rolled over/flipped. To support the management of roll-over meters, it is necessary to register the rollover value of the meter, against the test point/parameter, and then to report the first reading after the meter has flipped, as having rolled over. This enables the total accumulated value to be maintained accurately.
The Meter roll-over value is recorded on the Serial or Functional Object/Testpoints/Parameter. It can also be set from within the Manage Preliminary Reading assistant - e.g. the rollover value has not been set, the meter has rolled over, the new reading has to be corrected, and the rollover value needs to be recorded, as part of this process.
A reading may be incorrect for a variety of reasons - typically, it has been entered in error - e.g. entering a reading against the wrong parameter, mistyping, entering the wrong reading date. If a reading is detected as invalid on entry, it is set as a ‘Preliminary Reading’. One of the options in correcting this is to mark the reading as Incorrect. Optionally, a replacement corrected reading can also be entered in the dialog, if required.
Some readings will not be detected as invalid - they can only be judged as incorrect because of local knowledge. for example - a reading may have been entered that is too high - only the operator realise this. Therefore a recorded reading can also be processed, as incorrect.
Readings that have failed validation, and need to be set as incorrect, are dealt with using the Manage Preliminary Reading assistant.
Readings that have been registered as valid Recorded Reading, but then need to be set as incorrect, are dealt with using the Mark as Incorrect dialog.