Groups
A “Group” is a collection of simulation objects.
Groups are created by selecting the simulation objects and clicking the right mouse button. Groups can also be created automatically when you use the Duplication Wizard. An alternative method is to create an empty group using the Groups button on the Build tab and then selecting New. Click Add to select the objects that are to be members of the Group.
Add objects to an existing Group by selecting the objects to be added and then right clicking. The menu will have a new option “Add to Group” that will allow you to nominate the Group to add the object to.
To change details of a Group use Groups button on the Build tab.
A simulation object can be present in multiple Groups simultaneously.
Limiting capacity in multiple objects with groups
The number of Work Items in a simulation object is limited to the capacity of that specific object. In Queues, capacity can be set to any positive whole number and for an Activity, you can set the replication number. But what if you want to limit the total number of Work Items in a number of Activities and Queues?
Say you have a straight production line consisting of 4 pairs of Queues and Activities, and you can only deal with 5 Work Items at any given time in this part of the simulation.
First, select all the objects in this part of your model and right click within the selected area. Click on ‘Create group’.
Secondly, select the Group and click on 'Properties'. Now assign a name to your Group and tick the box ‘Limit Work Items in group’. Specify the maximum number of Work Items that can be in the Group at any one time. (In this example there is a Group limit of 5 Work Items, so enter 5 in the field after this option.)
Confirm your changes and you will not have more than 5 Work Items in the group of 4 Activities and 4 Queues at any given time in your simulation model.
Index with Groups
Activities can be “tied” together so Work Items exit at exactly the same time. This is known as Indexing and is particularly useful for applications where a Takt time is required.
Access Index with Groups through the Activity dialog Routing Out > More. This requires the relevant Activities to be added to a Group.
When set, the Activity will only allow an item to leave when every other Activity in the Group has also finished their jobs. Hence every Activity in the Group will input and output at the same rate, regardless of the cycle time of the individual Activities.