Page 461 - ExtendSim User Guide
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Miscellaneous 435
Biasing flow
☞ If the model contains Merge and Diverge blocks that are only set to the Batch/Unbatch, Pro- portional, or Select modes, bias has no impact on the effective rates.
Non-fixed rule modes
The Distributional, Neutral, Priority, and Sensing modes do not use a fixed rule to obtain or distribute flow. Instead, they provide a certain degree of freedom about where the flow can be directed.
A Merge or Diverge block in Priority mode, for example, impacts the flow as follows:
• Taking into consideration how much flow it can get, the block will do its best to direct as much flow as possible to its top priority branches.
• However, the block just expresses a “preference” for where to send the flow; model condi- tions determine how well those preferences can be achieved and the top priority branches may not actually get the most flow.
☞ If the model contains any Merge or Diverge blocks set to the Distributional, Priority, or Sens- ing modes, the bias order must be specified. (There is no bias order required for the Neutral mode.)
Setting a Merge or Diverge block’s bias order
When set to the Distributional, Priority, or Sensing modes, the Merge and Diverge blocks must express a bias order. This is accomplished as follows:
1) Bydefault,theExecutiveissettoBiasorder:definedbySimulationOrder.Withthis setting, the bias order for each Merge and Diverge block is automatically determined based on Simulation Order. Simulation Order is set in the command Run > Simulation Setup > Continuous tab; the default is Flow order. It would be unusual to change the simulation order from the default Flow order. (For further information on Flow order, see “Simulation order” on page 92.)
2) YoucanalsodirectlyenterabiasorderforabiasingMergeorDivergeblock.Todothis, first change the Executive’s default setting from Bias order: defined by Simulation Order to Bias order: each block defines its own. Then do one of the following:
• In the block’s Model Set- tings tab, use the two array buttons (“<<” and “>>”) to change the block’s bias order. This also changes the block’s position in the tab’s bias order table.
• Or,intheExecutive’sDis-
crete Rate tab, select the
row that contains the
desired block, then use the
<< and >> arrows to
change its position in the
table. The bias order
changes when the position of the block in the table changes.
Model Settings tab
Discrete Rate

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