Every mission starts the same way. Someone creates a spreadsheet. Column A is the requirement ID. Column B is the text. Column C is the parent. Maybe there is a Column D for status. It works for the first 30 requirements.
Then someone inserts a row. The parent references shift. Someone copies a tab for a new subsystem and forgets to update the cross-references. By PDR, the spreadsheet has 400 rows, six tabs, and no one trusts the traceability links.
The core problem is that spreadsheets do not understand relationships. A cell reference is not a traceability link. When you change a requirement, the spreadsheet does not know which downstream requirements are affected. There is no suspect link detection. There is no coverage analysis. There is no way to ask "show me every requirement that traces to this mission objective" without manual filtering that takes 20 minutes and might miss something.
This is not a criticism of Excel. It is a recognition that traceability is a graph problem, and spreadsheets are a table tool. The right answer is a tool that understands requirement hierarchies natively, maintains links as first-class objects, and flags downstream impacts automatically when something changes.
SMAD Portal builds the traceability matrix as you work. When a requirement changes, every downstream link is flagged as suspect. Coverage gaps are visible in real time. The RTM is always current because it is generated from the live data, not maintained by hand.