How do I estimate first-pass yield for a new ramp?

Use the closest proven product and line, then hold the figure low for the first weeks. First-pass yield counts only units that pass without rework, so a line with rework loops scores worse than its total good output suggests.

Why is yield applied after uptime?

Defects only afflict units the line actually builds. If uptime removes 18%, 5,040 gross units become 4,132 started units, and a 4% yield loss then costs about 165 units, not 202. Applying both rates to gross capacity overstates both losses.

What counts as peak-season demand?

The good units the plan must ship during the peak window, after any channel inventory you already hold. Use the forecast for the same weeks the ramp covers. A full-season total hides whether the peak weeks alone can be served.

Should the ramp plan include overtime?

This page measures the line as entered, so add overtime hours as extra planned cycles rather than raising the cycle count. If overtime is not yet approved, keep it out and let the shortfall warning show the exposure the peak carries.

Consumer Goods & Durable Products Manufacturing calculator

Seasonal Ramp Capacity Calculator

Size a seasonal ramp before the holiday build: gross cycles times units per cycle, then uptime and first-pass yield losses, then the gap to peak demand. Enter the line's demonstrated numbers, not the rates you hope for.

What this calculator does

Good units a seasonal ramp can build after uptime and yield losses, with each loss priced and the gap to peak demand.

Formula used

Gross ramp capacity = units per cycle × planned cycles
Uptime capacity = gross capacity × line uptime ÷ 100
Good ramp capacity = uptime capacity × first-pass yield ÷ 100
Lost to downtime = gross − uptime; lost to defects = uptime − good
Capacity gap versus peak demand = good ramp capacity − peak demand

Inputs explained

Finished Units per Line Cycle: Finished units one line cycle produces at the demonstrated pace.
Planned Ramp Cycles: Ramp cycles planned for the season or peak window.
Seasonal Ramp Line Uptime: Share of planned cycles the line actually runs.
Seasonal Ramp First-Pass Yield: Share of produced units that pass without rework.
Peak-Season Demand: Good units the peak season must ship.

How to use the result

Best suited to planning a holiday appliance build, sizing overtime before a seasonal peak, checking a line before a peak season.
Changeover, ramp-up learning and overtime are not modeled; a new line rarely hits the entered rates at first. The two loss rates compound, so remeasure both after a reliability or quality fix.

Common questions

How do I estimate first-pass yield for a new ramp? Use the closest proven product and line, then hold the figure low for the first weeks. First-pass yield counts only units that pass without rework, so a line with rework loops scores worse than its total good output suggests.
Why is yield applied after uptime? Defects only afflict units the line actually builds. If uptime removes 18%, 5,040 gross units become 4,132 started units, and a 4% yield loss then costs about 165 units, not 202. Applying both rates to gross capacity overstates both losses.
What counts as peak-season demand? The good units the plan must ship during the peak window, after any channel inventory you already hold. Use the forecast for the same weeks the ramp covers. A full-season total hides whether the peak weeks alone can be served.
Should the ramp plan include overtime? This page measures the line as entered, so add overtime hours as extra planned cycles rather than raising the cycle count. If overtime is not yet approved, keep it out and let the shortfall warning show the exposure the peak carries.

Last reviewed 2026-10-01.