How is SCAR cycle time calculated here?

By Little's law: average time in queue equals queue length divided by throughput. Forty-six open actions closing at twelve a month is 3.83 months, about 115 days at the stated 30-day month.

What is a good SCAR closure cycle time?

Automotive and aerospace supplier manuals commonly expect containment within 24 to 48 hours and full 8D closure inside 30 to 60 days. An average of 115 days breaches that commitment in bulk, because the tail sits far above the average.

Why does the arrival rate matter?

Because Little's law assumes a steady queue, and arrivals versus closures tests that. Arrivals above closures grow the queue, so today's cycle time is a floor that worsens monthly; arrivals below closures drain it.

Should I raise the closure rate or cut arrivals?

They fix different things. Closure capacity moves level and direction: raising twelve to twenty cuts the average from 115 to 69 days and turns growth into drain. Arrival reduction fixes direction without adding reviewers.

Supplier Quality, Development & Audits calculator

Supplier Corrective Action Cycle Time Calculator: Queue Math

Read a corrective-action queue with the arithmetic queues obey. Enter open SCARs, monthly closure and arrival rates and your target; average days, backlog and net growth come back.

What this calculator does

Read a SCAR queue with Little's law: average days, queue direction and the gap to target.

Formula used

Backlog in months = open SCARs ÷ SCARs closed per month (Little's law)
Average days to close = backlog months × 30
Net queue growth = new SCARs − closed SCARs per month
Gap to target = average days to close − closure target

Inputs explained

Open Supplier Corrective Actions: Live SCARs and 8Ds awaiting closure in the quality system.
SCARs Closed per Month: Actions actually closed per month over recent months.
New SCARs Opened per Month: New actions opened per month over the same window.
Closure Target: The closure window customers or your procedure expects.

How to use the result

Best suited to sizing review capacity after an escape wave, setting a closure commitment from real rates, spotting a structurally growing SCAR queue.
Little's law gives the average, not the tail: stalled actions sit far above it. Supplier response delay is inside the closure rate, not separated from reviewer capacity.

Current U.S. benchmarks

U.S. manufacturing runs at 75.7% of capacity (Federal Reserve, Aug 2026). New factory orders are up 8.5% year over year (Census).

Common questions

How is SCAR cycle time calculated here? By Little's law: average time in queue equals queue length divided by throughput. Forty-six open actions closing at twelve a month is 3.83 months, about 115 days at the stated 30-day month.
What is a good SCAR closure cycle time? Automotive and aerospace supplier manuals commonly expect containment within 24 to 48 hours and full 8D closure inside 30 to 60 days. An average of 115 days breaches that commitment in bulk, because the tail sits far above the average.
Why does the arrival rate matter? Because Little's law assumes a steady queue, and arrivals versus closures tests that. Arrivals above closures grow the queue, so today's cycle time is a floor that worsens monthly; arrivals below closures drain it.
Should I raise the closure rate or cut arrivals? They fix different things. Closure capacity moves level and direction: raising twelve to twenty cuts the average from 115 to 69 days and turns growth into drain. Arrival reduction fixes direction without adding reviewers.

Last reviewed 2026-10-01.