Predictability is often cited as the most desired and valuable characteristic of a color managed workflow. It's also been one of the most difficult to achieve. A widely recommended approach involves sticking with a single CMM (Color Management Module) and using color profiles created with a single profile creation tool. Even then, getting a color workflow working remains a trial-and-error process.
We have little or no insight into the algorithms used by the profile creation tools: these are usually proprietary. You may generally like the way a particular CMM works, but when it lets you down, there is no easy way to find out why. The internals of most CMMs are also, proprietary. Current color management systems tend to be collections of black boxes. We can create new black boxes, or swop others in and out in an effort to make our workflow produce the output we want... but, we are fundamentally juggling black boxes.
This situation lead to our policy of complete transparency with respect to WCS internals. We fully documented all of the algorithms used in WCS's device models, gamut mapping models, and color translation pipeline. Our actual internal design documents for WCS have been available under NDA since June of 2004. Further, we are committed to make the WCS documentation public prior to the market release of Windows Vista.
Because WCS provides a well documented set of baseline device models, baseline gamut mapping models, and a fully documented processing pipeline, color workflows that rely on these baseline models are assured of understandable, consistent, and predictable color processing.