Production: Assigning a press to a job

We have more than one press that can run the job, how is the press assigned and scheduled in PrintJobManager? 
So the situation is your shop has more than one press that could run the job. Whether you are asking how to assign a job to a press, or how to assign a press to a job, it's really the same thing. The larger question is how is the job assigned to a specific press when there are more than one press that could be used?
Product Engines and Presses
In PrintJobManager, a job's production steps, equipment, and raw materials are assigned automatically by the product price engine (for example: Postcard, or Banner, or Business Card, etc.) used to generate the job or estimate. Built into the product engine will be a printing option (for example 1/1 and 4/4, etc.). Tied to this printing option will be the press you intend to use for producing the product. For example, a Postcard may be run on a Speedmaster 74 press or on a CD 102 press.
You normally don't tie both presses to the engine or job, but would choose one press instead.
Option 1. After creating a "Postcards Speedmaster" product engine based on the Speedmaster 74, duplicate the product engine, rename it "Postcards CD" and edit the assigned press to use the CD 102. Of course, you can use a different naming convention if you don't want a press name.
Now PrintJobManager will have 2 product engines for postcard jobs, Postcards Speedmaster and Postcards CD .  When you create a new Job (or Estimate) you can choose whichever product engine is appropriate at the time. If it runs on that press you are done. It is already assigned to the correct press and you can use the Scheduling by Resource section to schedule the Speedmaster 74 jobs.
If after the job is created it is decided to run on the CD 102 press instead, the user can edit job, select the Postcards CD product engine and save the job (now assigned to the CD 102 press). Now that job will show up on the CD 102 schedule in the Scheduling by Resource section.
Option 2. You can create a product engine with a question asking which press to run on, with a list of applicable presses. The user selects a press, or it could be left to a default. Later, if the job is to be run on a different press, the user can edit the order, select a different press from the list. A product engine like this would normally be for internal use, rather than connected to a Pressero store. Scheduling on whichever press is selected would work as above. 
Option 3. A hybrid approach. Let's say you have 10 identical presses to choose from, some perhaps in a different location and you want the product engine to be used in a Pressero store. Follow Option 1 above based on a press, but when duplicating the product engine, make a version that has the press drop-down menu selection (press 1, press 2, press 3, etc.). When the order arrives, edit the job, select the "multipress" version of the product engine with the press list and make your press selection.