Most spreadsheets show #N/A or #DIV/0! . Daniel T. Li hates this. His spreadsheets never produce errors; they produce graceful degradation . Using nested IFERROR and IFNA functions, his sheets display user-friendly text like "Data pending" or "Check vendor ID." This ensures that decision-makers never panic when a cell breaks—they simply know what action to take.

: Many of the spreadsheets, such as those for two-story moment frames or discontinuous shear walls, utilize finite element analysis to provide precise structural results. Code Compliance