Input variables
| Variable | Meaning | Unit |
|---|---|---|
| stitches | Stitches per design | stitches |
| speed | Effective stitching speed | stitches/min |
| changes | Color changes per design | changes |
| change | Seconds per color change | s |
| handling | Handling per item | minutes |
| items | Items | items |
Equations
Sewing per item · minutes
sew = stitches/speed
Total per item · minutes
each = sew+changes*change/60+handling
Whole run duration · hours
run = each*items/60
Notation
PI means π. ** means a power, sqrt means square root, and abs gives the absolute value. Trigonometric functions use radians. min and max select the smallest or largest argument.
ceil rounds upward, floor rounds downward, and round rounds to the nearest integer with halves toward positive infinity. roundup(value, step) rounds upward to the next multiple of the step; a zero step leaves the value unchanged.
Assumptions
- Use observed effective speed rather than the machine’s advertised maximum.
- Thread trims, breaks, bobbin changes and dense stitch areas create extra downtime.
- Multi-head production requires a different model; this estimates sequential item processing.
- Test sewouts are additional to the requested production quantity.
Precision and verification
The tool uses ordinary double-precision numeric arithmetic. Output is displayed to at most four decimal places; measurement precision is usually much lower. Check the worked examples, your project’s specifications, and a real sample before committing material.