Traditionally data modeling is done using ERD diagrams using tools like `Erwin` (Proprietary) and pipeline design is captured in Data Flow diagram using tool li

Traditionally data modeling is done using ERD diagrams using tools like `Erwin` (Proprietary) and pipeline design is captured in Data Flow diagram using tool like `MS Visio` Opensource alternative are available for both tools. In my experience BA's generally prefer to documents requirements using Excel.