This one is under the floor rather than on the surface. Order processing has been rebuilt so that each part of an order is calculated by one piece of code, consistently.
One Path for Every Order
Customer, dates, items, prices, promotions, order number, rounding and tax each have a single processor, whether the order came from the counter, the website or an agent.
Rounding and Tax, Once
Company rounding and tax are applied in one place, which is what keeps a total from differing by a cent between two screens.
Work Orders Follow Automatically
Work orders and their tasks are derived from the order as it is processed, rather than assembled separately afterwards.