The engineering question
Common failures include using part footprint instead of projected area, comparing a PS shot rating as if it were material-neutral, mixing solid and melt density, omitting runner/cushion, and using unmatched time windows for output or scrap.
What to document
A calculator should preserve the input source and definition so a second engineer can reproduce the estimate.
Practical workflow
Cross-check Shot Size, Cycle Time, and Material Cost with their related guides.
Validation boundary
Use manufacturer documentation, grade-specific supplier data, controlled process records, and trials for any equipment, quality, material, or commercial commitment. A static calculator is a transparent starting point, not a simulation or approval.