Checking NCE Licenses' prorated usage

The following is a short recon check performed for ANS on their Customer Creative Car Park Ltd. They purchases two licenses with an Annual BillingCycle and wanted us to check whether the costs in CloudBilling were actually correct.

"I will start with two disclaimers. First of all, I will use the word 'usage' to indicate what should be more aptly described as 'the license being active'. Thus, 'three days of NCE License usage' means three days in which the license had an active status. Secondly, we will compare Cost in CloudBilling with Cost in the reconciliation file, since the cost remains consistent throughout price rule calculations. This while the value can still receive an uplift or discount.

We first looked at October. The calculation is shown in the red box. Since the license has been active all throughout the month and there was no change in quantity, we expect to see a full month's worth of usage and thus cost in CloudBilling. Since the Subtotal in the recon file is the cost for a full year, we divided it by 12 to get the cost per month. Whether this month runs from October 1st to 31st, or from October 2nd to November 1st (or any other full-month range) does not impact the Subtotal per month. If we divide both Subtotals in the recon file by 12 we get 1074 and 226.5. Adding these up, we would expect to see a Cost Total of 1300.5 in CloudBilling for October, which is exactly the number we see as costs in CloudBilling on the October invoice (see second image).

September is a little more complex. Since the license does not become active until the 27th, we do not expect a full month of usage. As such, we begin by calculating which part of the full month's usage we expect to see in CloudBilling in September. In the green box you can follow the calculation. The purchase date for NCE License purchases is 09:00 GMT. Therefore, this product is active for 3 days and 15 hours in September (Sep 30th we only count the usage from 09:00 to 24:00), or 3.625 days. To calculate it as a % of the full month we divide 3.625 by 30 and get 0.1208333. To find out which cost total we expect per product, we multiply the Subtotal per month we calculated in the red box by this 0.1208333 (blue box). When we sum the result, we get 157.14, which is exactly the Cost Total in Cloudbilling for September.

Therefore, we can conclude that the Cost total in CloudBilling is complete and correct."