Solid Cuts in MSSO

13/11/2014 Solid Cuts in MSSO

http://www.minesight.com/en-us/company/newsletters/may2012/solidcutsinmsso.aspx 1/5

May 2012

With the advent of version 4.5, MineSight Schedule Optimizer (MSSO) can now produce schedules based on solidcuts. Solid cuts can be useful as they negate the need to use a polygon to approximate mining geometry. Solidsrepresent the true area mined, and thus allow for a more accurate reflection of the reserve to be mined. Thisarticle will discuss the additional workflow steps required when you are scheduling solid cuts in MSSO.

The typical workflow for preparing reserves for MSSO follows these steps:

1. Cut Creation (Manual or using the Auto Cut Generation Tool) 2. Load Cuts to MineSight Interactive Planner (MSIP) Set 3. Assign Diglines using Digline Generator Tool (optional) 4. Compute MSSO Cycle Times using MineSight Haulage (optional) 5. Load Cut Reserves, Attributes, and Cycle Times to MSSO

When working with solids, we need to consider several different things at each of these steps in the workflow toensure that our data is prepared to work with scheduling in MSSO. The biggest consideration is that we mustdefine a new attribute, mssoLevel, to indicate to which level cuts belong. This information will be used forvertical precedence calculation in MSSO. At several places within the workflow we will take steps to ensure thatthis information gets populated to solid cuts automatically, allowing us to progress through the standard MSSOpreparation workflow without much extra effort.

In the new Auto Cut Generation plug-in, we are able to produce solid cuts using the Solids option.

While producing cuts using Auto Cut Generation, we can take the first step toward populating the mssoLevelattribute for each level of cuts. On the Naming tab, both $surfaceName and $gridPlane can be used as tokensfor defining the Material assigned to cuts at the Element level. Depending on whether you are using surfaces orgrid planes from a grid set to define your vertical slices in cut creation, you will choose the appropriate token toindicate the level number in the material that is assigned to each cut (See Figure 2 below). Later, when we areloading cuts to MSIP, we can automatically transfer this Material name to the mssoLevel attribute.



Note: The last level (by default, the lowest level) will not have a value assigned just by using the $surfaceName or$gridPlane token. The token value for the last level must be defined manually, by typing the value into theLeftover Solid Name field. In addition, if specified Material Names do not already exist, they will be createdautomatically during cut generation.

Hint: When using Auto Cut Generation with solids, some very small cuts can be created on the edge of the sourcesolids. It is recommended that very small cuts are either manually intersected with larger, neighboring cuts usingthe Intersect Solids Tool, or removed altogether if small enough to be inconsequential. Configuring the SelectionFilter to filter on solid volume can be useful for finding these very small cuts.

When loading cuts to MSIP it is important to remember to transfer the appropriate geometry attributes to MSSOattributes in the MineSight Planning Database (MSPD). There are often (but optionally) two attributes to bedefined at this point mssoPhase and mssoLevel. The mssoPhase is often assigned to the Object Name of theobject containing the cuts, or as the element name of each individual cut. If the process above was followed,mssoLevel will be assigned to each cut as a Material. If you are loading cuts directly in MSIP using the ImportMultiple function, you can align each MSSO attribute with its corresponding Geometry attribute on the AttribImport panel in MSIP. If you are using the em-ImportCutstoMSPD.pyz script to load cuts, you can align attributeson the Import tab.



Similar to when scheduling with polygonal cuts in MSSO, the Digline Generator will be used to define diglines forsolid cuts. When using the Digline Generator with solid cuts, it is important to remember that not all solid cutswill be visible in a given plan section through cuts. Thus, if you are digitizing leadlines based on a sectional viewthrough solid cuts, it is possible that the leadline will not pass through all cuts (see Figure 5 below). Rememberthat in order for a cut to be assigned to a digline using a leadline, the leadline must physically pass inside theboundary of the cut.



The Digline Generator will lend a hand with this issue. When assigning leadlines, it will divide cuts into specificPartitions depending on which leadline passes through them. Any orphaned cuts that were not assigned to aleadline will exist in their own partition. Highlighting each single cut partition in the Digline Generator willhighlight the small orphan cut in the viewer. Once these cuts are found, leadlines can be adjusted to includethem. Alternately, cuts could also be deleted or merged with larger neighbors.

Cycle Time Calculation in MSHaulage for solid cuts is nearly identical to the process used for polygonal cuts. Theprimary difference is in where material is sourced in MSHaulage. For polygonal cuts, material is assumed toexist at the center of a given cut, on the toe of the bench to which the cut belongs. Thus, for polygonal cuts, allmaterial is routed at the toe of the bench. For solid cuts, material exists at the center of the solid cut, without anyadjustment to the toe of a given bench. Thus, by default, material is routed at the midlevel for each cut.

Because material is routed at the midlevel of the solid cuts, you will need to ensure that source roads areavailable for all cuts in the IP set. This can be checked by using the IP Sourcing validation option in MSHaulage(Validation IP Sourcing).

Loading data into MSSO is nearly the same for solid cuts as it is for polygonal cuts. In the Project Setup, you willneed to define the mssoLevel attribute under the MSSO Attributes for the source. Then, in the Precedencepanel in MSSO, you will need to order the levels from top to bottom as shown below in Figure 6.

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Solid Cuts in MSSO