Substitutes

A part runs out, gets discontinued, or costs too much this week. Substitutes keep the work moving. PartsBox carries them through pricing, purchasing, and builds, so a shortage on one part never blocks an order or a build. It gives you three levels of substitution, matched to how sourcing actually works. Most tools offer a single flat list.

• Meta-parts group interchangeable parts under one name that you use in a BOM. The meta-part shows the combined stock of all its members, and low-stock alerts work at the group level. Use it for parts that are equivalent everywhere, such as the same component in two package variants.
• Part substitutes give one part its own list of approved replacements. The substitution applies in every project, BOM, and purchase list, but each part keeps its own stock. This suits passive components with many functional equivalents.
• BOM substitutes set an alternate on a single BOM line, for a substitution that applies to one project and nowhere else.

When you price, purchase, or build, PartsBox combines all three and treats the main part and its substitutes as equally valid. Offers are gathered across the whole group and the best one is chosen from the combined pool, so a substitute can lower the price, not only cover a shortage. When the same part carries different substitutes in different places, PartsBox uses only the common ones, so a purchase list never assumes a substitution you did not intend.

A substitute must share the part's unit category: a part measured by length can be replaced only by another measured by length, and a part counted in pieces only by another counted in pieces.

Meta-parts and part substitutes are in every plan, including the free Maker plan.