Collect/Assemble Work Items

This method of “routing” Work Items into an Activity lets you collect a number of Work Items from a number of places, before you start processing them.

For example you might want 12 bottles of whiskey and 1 box; you might need 100 units before you put them to the oven as a batch; or you will need a passenger and his suitcase to be present before you can open the suitcase at an airport security.

Only when the number of Work Items required have all been collected, the Activity will start work.

How to use Collect

Collect is a Routing In Discipline and can be found on the Activity’s Routing In dialog. By using the text box next to Collect, we define how many Work Items have to be collected from the highlighted Queue. The only building blocks from which an Activity can collect Work Items are Queues and Activities.

Collect Options

Do Not Collect Until All Available

This option tells the Activity not to collect ANY of the required Work Items from their feeding objects until all the required Work Items are available. This option is only available if all the feeding objects are Queues.


Matching causes the Activity to collect only items with identical label content (checking the “Matching” check box will allow you to select the label name to use). For example, at an Airport’s Security process, you can match a passenger with their suitcase. Unique Labels are commonly used for this purpose.


Assemble (the default) pulls together all the items collected into a single Work Item. Uncheck this box if you want all the Work Items kept separate. For example, in a manufacturing environment parts are assembled for goods to be produced.

Assembly time-in-system from:

When assembling Work Items, you can specify which of the individual Work Items will dictate the time in system result of the assembled unit. You can choose from the following options:

  • First collected: Use the time on the first Work Item collected
  • First in List: Uses the time on the Work Item that comes from the first source Object in the list of source Objects above.
  • Youngest: Uses the most recent time found on any of the collected Work Items
  • Oldest: Uses the time on the oldest of the collected Work Items
  • Set to Now: Uses the time that the final Work Item is collected (The time in system for the Work Item started at the time it was assembled at the Activity).
Label Values from

When assembling Work Items with different Label values, Simul8 has to make a choice of which of these values will be applied to the newly assembled item. Label Values of the final Assembled Work Items can be sourced from either:

  • The Work Items with the Highest label value (the default setting)
  • The Work Items with the Lowest label values.
  • The Selected Route: You can select the route highlighting one of the source Objects on the Routing In dialog.

Label / Sheet

Checking the Label / Sheet option will allow the activity to use Simul8 2015's Variable Collect feature. This will allow you to define how many Work Items that will be collected, based on another Work Item's label value.

Once Label / Sheet is selected, a dialog named Label and Sheet for Collect Routing In will appear.

Use the Select label dropdown to choose the label that will be referenced to control the collection of items.

Use the Select sheet dropdown to choose which spreadsheet to use, which will contain a matrix of how many Work Items need to be collected from each incoming queue.

Use the New button at the side of each dropdown to create a new label or sheet if you do not yet have any labels or spreadsheets in your simulation, or you wish to create a new label and sheet to use for Variable Collect.

High Volume If you use “collect” routing in with a high volume Activity then each Work Item does not count as 1 as the items are accumulated. Instead Simul8 looks at the quantity label on each Work Item an uses its value to determine how many Work Items to bring into the Activity. If necessary a Work Item will be split into two Work Items to leave some “quantity” in the queue and bring some into the Activity.

See Also