Rehandle group allocation

A rehandle group defines a set of material movements from a stockpile to another node, such as a crusher. The movements are termed “rehandle” because they involve relocating previously placed material. Performing rehandle for the movements within a group is treated as an activity.

Configuration steps

Rehandle groups are defined in Site Management > Material Flow Diagram.

For more information about rehandle groups, refer to Rehandle groups (rehandle movements).

Rehandle rate factor

When a resource is assigned to a rehandle group, a Rehandle Rate Factor field appears in its configuration. This field defines the percentage of the resource’s rehandle production rate that will be applied during a given period.

Example calculation

If a resource has:

Then the actual production rate for that period is 600 × 0.85 = 510 t/h

Varying factors across periods

Resources can have varying time usage factors, resulting in operating times or production rates that ramp up or down over periods. The factors could vary over days, weeks, or months, and so on.

For each factor, the default expression is simply 100%, making the value consistent across each period – resulting in a static operating time or production rate (ignoring any activity area rates).

Using a dynamic expression, or by manually overriding periodic values, you can make the time usage factors vary across periods.

Dynamic expression

A factor’s default expression sets its value across all periods. The expression must return a factor, between 0 and 1, representing a percentage of time (e.g., 0.85 = 85%).

The expression can evaluate certain attributes of a period to derive a value.

Field

Type

Description

Period Duration

Number

Duration of the current period

Period Finish

Date Time

End date of the current period

Period Id

Text

Identifier of the current period

Period Name

Text

Name of the current period

Period Number

Number

Sequence number of the current period. The first period is counted from 1.

Period Start

Date Time

Start date of the current period

The expression can also reference custom calendar fields. A calendar field returns its value for the current period.

Expression examples

Consider this example, which uses the following calendar:

Number

1

2

3

4

5

6

7

Name

Sun

Mon

Tues

Wed

Thur

Fri

Sat

For the given resource, to automatically vary the entered production rates, based on attributes of each period, the following expressions are entered:

Field

Default Expression

1

2

3

4

5

6

7

Availability

IIF(PeriodNumber < 3, .9, 1)

90%

90%

100%

100%

100%

100%

100%

Use the function IIF(logicalTest, valueIfTrue, valueIfFalse)
If the period number is below 3, use 90%. Otherwise, use 100%.

Utilisation

IIF(PeriodNumber >= 2 And PeriodNumber <= 4, 0.95, 1)

100%

95%

95%

95%

100%

100%

100%

If the period number is equal to or between 2 and 4, use 95%. Otherwise, use 100%.

Efficiency

IIF(InStr(1, PeriodName, "Sat") > 0 Or InStr(1, PeriodName, "Sun") > 0, 0.8, 1)

80%

100%

100%

100%

100%

100%

80%

Use the functions IIF and InStr(startIndex, inputString, searchString)
1 is the starting position (the beginning of the string). Within the PeriodName field, search for the Sat and Sun substrings. If those strings are identified, use 80%. Otherwise, use 100%.

Rate Factor

IIF(PeriodNumber <= 5, Choose(PeriodNumber, 0.8, 0.85, 0.9, 0.95, 0.96), 1)

80%

85%

90%

95%

96%

100%

100%

Use the functions IIF and Choose(index, choice1, choice2…)
If the period number is equal to or less than 5, use the period number as an index to select the factor from a list. Otherwise, use 100%.

Overrides

You can override any resource field value. Overriding fields is useful when:

To override a field, select it, then enter a new value. Overridden fields and values are highlighted in orange.

Field

Default Expression

1

2

3

4

5

6

7

Availability

1

100%

100%

90%

100%

100%

100%

100%

Utilisation

.95

95%

95%

95%

96%

96%

96%

96%

Efficiency

.95

95%

100%

95%

95%

95%

95%

95%

Rate Factor

1

100%

100%

100%

100%

100%

100%

100%

An example of overriding fields

On the right-click menu of a cell, you can select these options:

Copy from Excel

You can copy multiple lines of cells from Excel and paste them into the table cells to rapidly populate the fields.