Plant Usage - Assumed Daily Rate

• The calculation of the Assumed Daily Rate is fundamental to the scheduling of Plant Service Order Start Dates, and is the average usage of a Plant Item, in the units recorded by the meter. It is automatically updated as a result of meter readings that have been entered

• Meter readings will be entered for a Plant Item as they come to hand. For some plant this may be a structured daily recording, whilst for other plant the readings may be received on a very irregular basis.

• For non Calendar Based meters (e.g. Kms, Hours etc), we record an Activate Meter Reading against each Plant Service Order. This is the meter reading at which the service under the PSO is due. By calculating this Assumed Daily Rate average usage, we can accurately determine on what date this meter reading will be reached.

The calculation involved is:

• (Activate Meter Reading – Latest Meter Reading) / Assumed Daily Rate = a number of days.
• This number of days + the date of the latest meter reading, = the expected Start Date for this service

There are a number of rules and scenarios that apply to this calculation. Examples are given for each scenario in the Plant Meter Readings section which follows:

The basic Assumed Daily Rate calculation is:

• Total Days since the first meter reading = date of this reading - date of first reading
• Total Distance since the first reading = this reading – first reading
• Assumed Daily Rate = Total Distance / Total Days

If the entry of a meter reading results in a change to the Assumed Daily Rate of more than the 'Assumed Daily Rate Change Threshold' the user will be prompted as to whether to accept the change or not. This is to allow some control over this value. E.g. there may have been some abnormal usage over a few days, but if this will not be the future pattern then you may not wish to change the rate.
There are Control Parameters which control whether the user is warned of this or not.

Note the use of the 'Records for Assumed Daily Rate' entered against the Plant Item Meter. This is the default number of the most recent meter reading records to be used in the calculation of the Assumed Daily rate for this meter. If the usage pattern changes over time, you may want the Assumed Daily Rate to be calculated only on the more recent usage pattern. The 'Records for Assumed Daily Rate' default to 999, but can be changed.

IMPORTANT:
The Assumed Daily Rate calculation makes no allowance for weekends or days not being worked. The number of days is simply a calendar difference between meter reading dates. Whilst this will give variances in the Assumed Daily Rate across small time periods, the average will be realistic across longer periods. The system setup required to control the usage recording at a more detailed level is unrealistic.
Remember that the use of the Assumed Daily Rate is primarily to calculate the recommended start date for a particular service. This date can be reported on, and can be changed.