Semi Additive Measures in SQL Server Standard Edition

A few years ago, Alex Whittles wrote a very detailed explanation about semi additive measures in a SQL Server Standard Edition. For my post today I'm concentrating on some other ideas, especially on dynamic sets in SQL Server 2008. Semi additive measures are measures that have a different way of aggregation over time (or other specific dimensions). For example, thinking of stock values you want to sum them up by product, location, country etc. but not by time (here you may want to see the last value, the average, the minimum/maximum or whatever).