[Bamboo Knowledge Base]
Bamboo's concurrent builds feature allows you to build a plan concurrently on several agents. You might find this useful if a plan is likely to be triggered again before the current build completes.
You can configure a default value for the maximum number of builds of a plan that your Bamboo server can run concurrently, using the Bamboo administration console. This value is a default – it can be overridden on the Miscellaneous tab of a plan's configuration.
You need to be a Bamboo administrator to configure concurrent builds.
To configure the number of concurrent builds of a plan allowed by Bamboo: