Skip to 0 minutes and 15 secondsIn order to make decisions or to embed the logic and the real-life problems using this software we can drag and drop a diamond shape called Decide. This Decide module or Decision module would take us to two destinations based on chance, if we say 40% of it users would go this way 60% would go this way two-way chance. Or, it could be by conditions and this conditions would be based on a variable value that we defined using the assigned module. Or, it could be using the attributes; whether the passenger tickets are type of economy or business class. Or, it could be based on the entity type. We have another type of decision. We call it decision based on an expression.

Skip to 1 minute and 7 secondsSo, if we drag and drop the Decide module we should be able to decide based on a condition and if our condition is an attribute then we can decide whether to go to destination one, if our attributes set to one, or destination two, if our attribute set to two. Or, if it's based on variable then we can make our decision based on the variable. So, for example any entities greater than or equal to three should go to the first destination 'Leave' otherwise the rest of the entities could go to the second destination which is 'Dispose 4'. To run the model we can see entity number one less than three, less than three, three or greater, three or greater.

Skip to 2 minutes and 23 secondsSo, this Decide module can be placed here to decide whether to select destination one or destination two. In this type of decision we have a decision based on chances. So, 'Decide', 'Decide based on chance' in which we can set this to 75%, to say 75% of entities to go to the 'Leave' destination, 25%, or the rest, will go to the other destination. Once we run the model you should be able to see the effect of adding this decision module and it's very important to have a logic embedded in our real-life problem.

The Decision module

This module allows for decision-making processes in the system.

It includes options to make decisions based on one or more conditions (eg at a quality inspection point, if the entity type is pass or fail) or based on one or more probabilities (eg 75%, true; 25%, false).

Typical uses include dispatching a faulty part for rework, branching accepted vs. rejected checks, or sending priority customers to a dedicated process.

Conditions can be based on:

  • Attribute values (eg change the status of a product after inspection to either pass or fail)
  • Variable values (eg counting up to 10 boxes to fit on a pallet with a capacity for 10 boxes only)
  • The entity type (eg differentiating between economy class or business class booking types)

There are two exit points out of the Decide module when its specified type is either 2-way by chance or 2-way by condition. There is one exit point for ‘true’ entities and one for ‘false’ entities.

When the N-way by chance or by condition type is specified, multiple exit points are shown for each condition or probability and a single ‘else’ exit. The number of entities that exit from each type (true/false) is displayed for 2-way by chance or by condition modules only.

Share this video:

This video is from the free online course:

Simulation for Logistics: An Introduction

Coventry University