By the time the bricklayers are there to start on the project, most of the time the choice of cement mixture is already made. For most projects, a standard cement mixture is used and a custom one isn't even needed.

When issues do arise during the project, an expert is brought in/consulted. Standard cement formula's might change over time, for varied reasons, but it's not the bricklayers that keep themselves busy with that.

The same hold true for most IT projects.