Keep stock quantities, purchase records and the takeoff together.
Illustrative estimating scene. Use the source drawing, stated dimensions and calculation method for quantities.
- Hypothetical source A lists 12 pieces and source B lists 14 for the same mark.
- Do not merge the two into 26; retain both references and resolve the discrepancy.
- Source revision, scope and reviewer decision belong with the quantity record.
Define a stock group
A stock group should share material identity, grade, treatment or finish, actual cross-section and required appearance characteristics. The one-dimensional planner assumes every stock board within a run can produce any part in that run. If that assumption is false, the mathematical schedule can be unusable even when every length fits.
Avoid hidden substitutions
Do not let a label like “rail” conceal a different thickness or supplied profile. List the exact stock group on the exported record. When two boards have the same nominal label but different actual widths, preserve those dimensions independently. The general tool does not resolve product substitutions or assess compatibility.
- Make a separate run for each non-interchangeable group.
- Keep stock length availability specific to that group.
- Combine only the final purchasing summary.
Reconcile totals by unit
Linear footage can be added for logistics, but that aggregate cannot describe the full purchase specification. Board count, face area and physical volume should remain traceable to the individual stock groups. A combined number is useful only when its purpose is clear; it must not replace the detail needed to order the right material.
Keep incompatible stock out of the same pool
Group parts by the attributes that determine whether stock can serve them: material, actual section, profile, finish, grade or acceptance basis, and any required orientation. A total length across unlike boards is a reporting total, not a usable cutting pool.
Assign each part a group key before optimizing lengths. If two parts can share stock only after additional machining, record that as a separate operation and review the resulting profile. Do not silently assume the conversion.
A fictional project needs three material groups
| Group | Role | Why it stays separate |
|---|---|---|
| A | Pregrooved field boards | Requires the accepted field interface |
| B | Perimeter boards | Edge condition differs from field |
| C | Fascia | Section and application differ |
A leftover from Group A should not automatically reduce the purchase quantity for Group B. It may have an exposed groove or another mismatch. Keep the proposed reuse unresolved until the actual part requirements permit it.
Export the grouping fields with the purchase list. A supplier receiving only a combined linear-foot total cannot reconstruct the distinctions. Review quantities within each group before adding a project-wide summary.
Worked planning example
An assembly needs 5/4 appearance boards and 2-inch framing members. Even if both are available in 12-foot lengths, they belong in separate cut plans. Combining them could assign a framing part to appearance stock solely because a remainder looks large enough.
Common questions
Can I mix widths in the cut planner?
No. Run each cross-section separately. It does not model ripping or two-dimensional nesting.
What if two species have identical dimensions?
Keep them separate unless the design and purchase requirements explicitly make them interchangeable.
Evidence & limits
- Calculation method: dimensional arithmetic and conservative first-fit packing
- NIST PS 20-25 — measurement, tally and softwood size basis
Reviewed September 13, 2026. Sources support their stated technical principles; this site's workflows and hypothetical examples are not product tests, supplier approvals or independently reviewed project records.