I likewise follow a similar process to Taylor (multi page PDF made in Illustrator).
I work in footwear and Excel is common however for end use by the factory. I have a format that I’ve made as a final spec cost breakdown I have all the factory complete for all final products. It allows a much easier review of each part supplier name, material, color, usage, cost, loss, etc. With so many components and as a costing tool this is easy to use.
Illustrator or a PDF is good for initial spec, but if the supplier can’t update it, they can’t ensure the spec is up to date following any revisions. After initial samples, the original spec is pretty much useless aside from a place for the supplier to write notes on and manually update on paper. There is normally very little point in updating a drawing or PDF spec after each round as the sample is the living spec.
The excel CBD is just for costing and reference. The CFM sample is the “spec”.
R