Clearly, the more you know about your product, the better your model becomes. A product bill of materials (BOM) is a great starting point. Other valuable considerations include supply chain, environmental regulation, transportation, and warehousing information.
LCA databases include many variations on factors that can help fine-tune your analysis. For example, valuable metals (like iron) used in industry exist in many states. A company may buy high-quality ingots for casting its flagship product. During production, machining operations may generate waste filings or shavings.
In an LCA, the ingots and the waste would occupy separate categories. Though the two materials have the same chemical composition, they have different flows and costs associated with their processes. Therefore, they must occupy different roles within the analysis.