From BOM spreadsheets to a reviewed model

What spreadsheets do well

They hold the tables engineers trust, the deductions learned over years and the special cases nobody else remembers. That knowledge is the valuable part, and it moves across.

Where they struggle

• Formulas hidden in cells, copied between versions and edited without review.
• No record of which version calculated a unit that has already been made.
• Floating-point arithmetic and silent rounding.
• Nothing stopping a size outside the range anyone has checked.

What moves, and how

• Tables import from CSV as values, with their keys and columns checked for duplicates.
• Calculations are rebuilt as named steps in the model, where each one can be tested.
• Conditions can be written in plain English and turned into precise rules.
• Known answers from your spreadsheets become worked examples that the model must reproduce exactly.

FactorySpec does not run spreadsheet formulas or link to a live workbook. The model becomes the reviewed source, and the spreadsheet becomes evidence.

Start with one family

Pick one product family where the spreadsheet is relied on every day and the outputs are clear. Its existing answers make the first set of worked examples.

Read next

• How FactorySpec worksFrom a modelled product family and worked examples to an approved release, an evaluated unit and its engineering pack.
• BOM rule examplesExample product rules in plain English, and what each does to a unit’s bill of materials: include a part, allow an option or block a combination.
• For made-to-measure manufacturersFor manufacturers of made-to-measure products such as frames, blinds, panels and enclosures: every unit’s parts, cut lengths and panel sizes from approved rules.