Here is a spreadsheet to show some examples of calculating patronage. "Patronage", as you may know, is the amount of work performed as a member of a worker cooperative, measured in accordance with the certificate of incorporation and by-laws. But how do you measure the amount of work performed?
The spreadsheet gives four examples, from simpler (with the greatest equality) to more complex. The first example uses hours worked as the measurement, and labor hours remain the building block through the examples. The second amplifies the amount of work performed by some hours by adding a "skill factor" to certain workers. This may be used where some labor contibutes a greater amount work, including special skills. The third example follows that format, but uses wage differentials as an index of skill, essentially assuming that pay is already measuring the amount of work performed (which may not be true - pay may measure seniority, for instance, but not greater skill). The last example is of a worker cooperative where there are different worker membership classes, and amplifies the work performed by some "special" class. This is the most unequal, but there may be cases in which it is useful to recognize a special contribution by some member classes if they are not recognized in other ways.
The best system should be fair, transparent and understandable, and agreed upon democratically - and enshrined in your bylaws before the fiscal year in which the work is performed.
There are surely other models, for example adding a skill factor for certain tasks or labor hours, rather than for certain laborers. I would interested to hear about your model in the comments if you have one to offer.