Order Triggers
An order trigger is a reorder point over the work sitting at one node. Set one on an Activity or a Queue and it watches how many entities of a chosen type are there. When the count drops below your level, it places an order, and the entities arrive through an Ordered Arrival after that arrival’s lead time.
It is the producer half of the ordered arrival: the arrival says how replenishment turns up, the trigger says when to ask for it. The tab is identical on an activity and on a queue.
This is not connected to the Inventory node, and it does not send a signal. It counts entities at this node and it schedules an arrival. Inventory items have their own separate reorder settings on the Items tab.
What a trigger holds
Section titled “What a trigger holds”| Field | What it sets |
|---|---|
| Target Signal | The entity type to count, chosen from the entities that reach this node through an ordered arrival. It also picks the arrival that will fulfil the order |
| Reorder Level | The count the node must drop below before an order is placed |
| Order Qty | How many entities the arrival creates |
| Place order at start | Fires one order at the very beginning of the run, with no lead time |
You can only add a trigger when the model already has an ordered arrival for an entity that reaches this node, and each ordered arrival takes at most one trigger, so build the arrival first.
What is counted
Section titled “What is counted”The count is everything of that entity type at this node right now: the entities inside it plus the entities in its waiting queue. ProcessModel then adds whatever is already on order and compares the total with your level. The test is strictly below, so a level of 5 orders at 4 and not at 5.
Adding what is on order matters: orders in transit are netted out, so a slow lead time cannot cause the same order to be placed over and over while the first is still coming.
When it is evaluated
Section titled “When it is evaluated”Every time an entity leaves this node, and at that moment only. Optionally once more at the start of the run if you tick Place order at start, which is a one-off.
It does not re-evaluate on arrival, on a schedule, or when anything else in the model changes. That is worth knowing when tuning a model: a node whose flow stops completely also stops checking its own reorder point, and the level it was sitting at when the last entity left is the level it stays at.
Setting the lead time
Section titled “Setting the lead time”The delay between placing an order and the entities appearing is the lead time on the ordered arrival, not a field here. Give it a number or a distribution.
It cannot reference an entity: no entity exists at the moment an order is placed, so an attribute or an Entity. reference in a lead time stops the run. Use a fixed value, a distribution, or a variable.
Related
Section titled “Related”- Ordered Arrival: how the replenishment arrives, and where the lead time lives
- Activity and Queue: the two nodes that carry this tab