Hi Ricardo,
The maximum amount will be defined by your license. This number can be found by opening up the License Manager. At the bottom of the window Is the number of simultaneous modules the license is set for.
However, we recommend keeping this number low. You can also give some consideration to the types of modules you will run on the server. If you have long running and/or process intensive jobs, you should probably keep this num ber to 1 so all server resources can be devoted to completing the jobs as quick as possible. With much smaller, quick running, less intensive modules, you can set this number to 2 or 3. When Alteryx runs a module, it can consume a lot of the server's resources in order to process the job. Adding another module to that mix and, depending on the specs of the server and the resources left, both jobs may start competing for them, extending out the how long it would normally take to complete the job.
I hope this helps