Daniel T. Li, Ph.D., S.E., is a prominent figure in the field of structural engineering, best known for developing an extensive library of professional structural design spreadsheets through his company, Engineering International Inc. .
to prevent accidental formula alterations, which can limit customization. specific structural template
: DTL typically sells licenses for the entire package rather than individual spreadsheets because many tools are linked to a shared database for full functionality.
Daniel T. Li teaches us that a spreadsheet is not just a grid of cells. It is a contract between the past (raw data), the present (transformations), and the future (decisions). By mastering his principles of referential integrity, layer separation, and functional purity, you stop being a user and become an engineer.
While these tools are highly regarded for their "in-house" feel and robustness, users should note they are often password-protected
Li rejects simple dropdown lists. Instead, he builds using INDIRECT only once (he makes an exception here with a warning). More often, he uses FILTER to create dynamic arrays: