Windchill Risk and Reliability Desktop Help > Windchill RBD > RBD Interface > Block Diagram How-Tos > Calculating the Optimal Number of Spares for a Block
Calculating the Optimal Number of Spares for a Block
As described in Spares Optimizations, replacing a failed unit with a spare generally takes less time than repairing it. If you have assigned a spares pool to a block as described in Assigning a Spares Pool to a Block, you can calculate the optimal number of onsite and offsite spares to have on hand. You can also calculate the optimal replenishment level for spares.
1. In the RBD Table, select the diagram.
2. In the diagram, double-click the block to open its Calculation Properties window. For more information, see Block Calculation Properties.
3. On the Spares page, if a spares pool has not yet been selected for Spares Pool, then select one. For more information, see Assigning a Spares Pool to a Block.
4. Under Optimize on this page, for each optimization to perform, do the following:
a. Select its checkbox.
b. For Minimum and Maximum, enter the values to use.
5. To indicate the spares optimizations to perform for another block, do the following:
a. Use the navigation control at the top of the Calculation Properties window to select the block.
For information about using this control, see Changing the Active Object in the Properties Window.
b. If a window opens for indicating whether you want to save changes made to the current block, click Yes.
c. For the newly selected block, repeat steps 3 and 4.
6. Repeat step 5 for each block for which to specify spares optimizations.
7. When finished, click OK.
Prior to running RBD calculations, you must ensure that the appropriate values for optimizing spares are specified in the Spares Optimization Parameters window. For more information, see Spares Optimization Parameters Window. You can either specify values now or when you next run RBD calculations.
8. To specify values now, see Specifying Spares Optimization Parameters.
The next time you run RBD calculations, optimal quantities are calculated for spares and replenishment levels based on specified values prior to calculating RBD results. For more information, see Calculating RBD Results. You can view the optimal quantities for onsite spares, offsite spares, and replenishment levels on the Spares page in the block’s Calculation Properties window. For more information, see Block Calculation Properties.