Have you learned about PCOS yet? PCOS is an old-style, C DLL invoked by the so-called WFC Totalizer Hook. The Totalizer Hook, implemented it in WFC 4.1 or 4.2, was a way to hook in some C processing in the Smalltalk totalizer. The Custom group at Kronos used the hook to perform three different alterations to totals, and it uses "configuration parameters" from one or more special database tables to control how it does this.
PCOS is a great utility but cannot be scoped given the numerous versions. There is no way to tell how it was programmed. There is no way to tell what it does. You can just pray the Kronos team in place when they made it for you did a decent job of documenting. One PCOS guy says, “It is wonderful, it lets you do all kinds of crazy moves after the totalizer is done.”
It was written originally because prior to WFC 6.0 there was no way to stop one kind of overtime (say, weekly) from being counted toward the other kinds (say, daily). You could change the order in which they piled up on each other, but you couldn't prevent one from being paid. Australia was the well-known place where this was considered unacceptable, so there are many PCOS DLLs floating around that country which are undoing the work of the WFC Sequencer Rule.
The intention of WFC 5.2 (the port to Java of the totalizer, but also the first introduction of external Java hooks for the totalizer) was to replace PCOS. It didn't work completely, because the Java hooks for the totalizer in 5.2 weren't sufficiently comprehensive to duplicate all of what PCOS can do. I don't know--but I rather doubt--whether Kronos has beefed up the totalizer and/or its Java extensibility framework to obviate PCOS.
It is possible that the counts-to feature of 6.0 is sufficient--along with using the Java hooks--to make PCOS unnecessary. But does anyone know this? I understand that there were many different versions of PCOS, so just because a Kronos customer says they have it, doesn’t mean you know what it does! My "Master Kronos AC" Luis recently dealt with replacing some PCOS code with clever configuration in 6.x. So far so good I hear!
Thanks to several unnamed sources in this article. It’s really hard to find good information about this very cool beast!