Combiner Node
TLDR: Combiner nodes synchronize multiple incoming agents before one combined output can continue. Use them when parts, documents, orders, or approvals must come together before the next step starts.
When To Use A Combiner
Use a Combiner when the downstream process cannot begin until required inputs are present.
- Assembly: frame plus wheel set becomes a bicycle.
- Kitting: several picked items become one kit.
- Order fulfillment: item plus carton becomes one packed order.
- Administrative work: application plus documents becomes one review case.
Matching Modes
| Mode | Behavior | Use When |
|---|---|---|
| Any | Combine a simple count of arriving agents. | You only care that enough inputs are present. |
| Attribute | Match agents that share a value such as order id or case id. | Parts must belong to the same order. |
| Recipe | Require a specific mix of agent types and counts. | One frame plus two wheels plus one seat. |
Modeling Notes
Combiners can create blocking. If one required input is late, the available inputs wait. That is useful when you want to see whether the process is limited by synchronization rather than raw processing capacity.
Useful first experiment
After a Combiner creates waiting, test whether speeding up the slow feeder beats adding capacity after the merge.