Precedences are used to define the relationships between activities. They are used to control the mining sequence when the option Obey Dependencies / Precedences is used and they are also used for inventory reporting.

If Activity n is defined as a precedence of Activity m, then it is assumed that Activity n should be mined before Activity m. Also, when Activity n is scheduled in a record, then it will release Activity m in that same record. The exact percentage of Activity m that is released by Activity n will depend upon the released percentage that is specified for Activity n in the input path.

The only limitation on precedences is that an activity cannot be preceded by another activity with a larger activity number than itself. Precedences can only be applied to activities within a record. To define the relationships between the records, dependencies are used.

Setting up Precedences

Precedences are set in the Productive Activities window. To define Activity n as a precedence of Activity m, place the activity number for Activity n in the Precedence column for Activity m. Note that Activity 0 cannot be assigned any precedences.

In the following window, the activity called Clearing (activity number 1) is defined as a precedence of the activity called Waste Drilling (activity number 2). Similarly, the activity called Waste Drilling (activity number 2) is defined as a precedence of the activity called Waste Mining (activity number 3), and so on.

 
The order of mining the activities, defined by the above precedences, is as follows.

Implied Precedences

In the example above, as well as the precedences that have been defined, there are a number of implied precedences.

Since Clearing is a precedence of Waste Drilling and Waste Drilling is a precedence of Waste Mining, then by implication Clearing will be a precedence of Waste Mining.

This becomes important when a particular activity does not occur in a record. Using the previous example again, consider a record which can be free-dug and therefore does not require drilling. The record will contain the Clearing and Waste Mining activities, but not Waste Drilling. The implied precedence then comes into effect to ensure that Clearing becomes a precedence of Waste Mining, as illustrated below.

Multiple Precedences

Any activity can have more than one activity defined as a precedence. In the following window, the activities called Drilling (activity number 1) and Ripping (activity number 2) are both defined as precedences of the activity called Mining (activity number 3). Note that when an activity has multiple activity precedences, the activity numbers are separated by commas in the Precedence column.

These activity relationships are illustrated by the following flow chart. Note that there is no relationship defined between the Drilling and Ripping activities in this example.

Precedence for Multiple Activities

An activity can also be a precedence for more than one activity. In the following window, the activity called Drilling (activity number 1) is a precedence for both Waste Mining (activity number 2) and Ore Mining (activity number 3).

 

 
These activity precedences are illustrated by the following flow diagram. Note that there is no relationship defined for the Waste Mining and Ore Mining activities in this example.