Use Primary Production as a Local Variable

Most worksheets will typically contain a labor or equipment component that has a time-related unit of measure, per day/per hour, which means that in order to transform that time-related unit of measure to a physical unit of measure like yd2 we need to apply a production rate, i.e. how many square yards can be produced per day?

We always divide by the production rate, as we need to determine what is our per yd2 cost, so if you think back to our Plastering example, if a general construction worker is paid $20 per hour of labor, work for an 8-hour shift and can plaster 30 yd2 per shift, then it costs us $5.33 (160/30) per laborer per yd2 of plaster.

This is why the transform calculations in the Plaster worksheet looked like this:

However, imagine that the general laborers are only mixing mortar and making sure the plasterer has it to hand. And they could actually mix enough mortar for 60 yd2 per day. Would it make sense to use a production rate of 50 for the general laborers?

No, because the plasterer can only plaster at a rate of 30 yd2 per day, so he is the constraining resource that ultimately determines the output and speed at which the item can be completed.

Thus, we can use the production rate of our plasterer to define our primary production rate {@p} as 30 and a better way to model our worksheet is then as follows:

Using the {@p} variable also allows us to easily update the ...