Final answer:
The Reserves to Production (R/P) ratio blends the issues of processing time and due date by dividing the estimated reserves by the current usage rate to forecast a timescale for resource availability.
Step-by-step explanation:
The ratio that blends the issues of processing time and due date is the Reserves to Production (R/P) ratio. This ratio is akin to forecasting how long resources will last given a constant rate of consumption. To illustrate, if you have a fixed amount of resource in reserves and you know the rate at which you are processing (or using) that resource, dividing the reserves by the production rate gives you a timescale for how long those reserves will last. Applying the earlier example, if you have $10,000 in savings and you spend $1,000 monthly, you can last for ten months without additional income. Similarly, for processing times and due dates, if you know the estimated resource available and current usage rate, you simply divide to find out for how long you can sustain that activity before running out of resources.