The quantity is how many CPU cores that the wM components have access to.
For your production environment, my guess is that you’re at the limit of your license with just one machine.
For the non-production environment, likely something similar.
For a given machine, you’re allowed to run as many instances as you want. As long all the instances have access to a max of 4 cores, however they are distributed and controlled, you’re good.
#Integration-Server-and-ESB#webMethods