...
Click Manage Jenkins > Manage Plugins > Available.
Select MultiJob.
Click Download now and install after restart to automate the downloading of the MultiJob plugin, and installing it, and then restarting the Jenkins server.
Click Manage Jenkins > Configure System.
Enter the number of executors [RC1] you want, in # of executors.
Click Create Job, andselect MultiJob Project.
Click Build > Add build step > MultiJob Phase.
From the Job Execution Type list, select Running phase jobs in parallel.
Click Build to run the MultiJob Project job.
...