You cannot plan and track your production program based on the number of units produced by using Project. But it is possible to achieve this based on resource’s time (that is, effort) in Project. Define the standard production rate, for example, x units per hour. And then determine your target volume, that is, the amount that you need to be produced per hour. Next define the task with the estimated duration corresponding to the target amount of production. You can also use custom fields to calculate the durations parametrically based on the standard production rate. Determine which one is the best for more accurate estimates, hours or days. Update the schedule based on how the production progress for each resource. The resource with low performance will need more time to produce the target amount, so the schedule will show delays for that resource’s schedule. In a nutshell, you can plan and track based on production time not the amount produced directly. I guess this is the simplest solution.