Modeling Multi-Item Packaging: Fitting a Bottle and Two Flutes in One Case

This article, the third in a series on packaging data modeling, examines how to design a single case that holds three objects of differing shapes and tolerances. The author argues that adding fixed fields for each cavity breaks as soon as the configuration changes, so cavities should instead be represented as a list within a shared spec. A validator is proposed that sums cavity widths, clearances, dividers and outer walls against the envelope width. Because each cavity is often specified by a different engineer, this additive check is frequently skipped until tooling is quoted. The author recommends that validators return the specific millimetre shortfall rather than a simple pass or fail, which makes the problem easier to fix quickly.