Build worksite site plan & show process flows in CAD

We are a manufacturing/project based company with warehouse/workshop - 4000m2, and movement of varying materials. We have a DXF file of site plan that we need updated.
Need to develop different layers of the plan highlighting different flows, etc. We require details such as racking layout, dimensions, yard layout, workshop/warehouse divisions, walkways etc.
As a future step we want to apply rendering and produce a 3D model of premises, including inside.