Yield analysis: usable output versus production inputs

Yield analysis compares usable manufacturing output with the production inputs that produced it. The useful answer separates units accepted immediately, units recovered through rework, final scrap, and work still awaiting a decision. This page measures physical production yield for a plant review.

Start with one product and a clear boundary

Choose a batch cohort: units started on identified production orders, followed through their recorded disposition. An October report can include batches started in October, but their final yield stays provisional until unfinished work closes. Do not mix October starts with all October completions if those completions include September work.

Use one unit throughout. For discrete parts, count pieces of the same product. For a material process, use comparable pounds and document conversion losses, moisture, and byproducts. Different products need their own measures unless an approved conversion makes them comparable.

Keep these definitions beside the export:

First-pass yield = Units accepted without rework / Units started

Current accepted-output yield = (First-pass good units + Good units recovered through rework) / Units started

Final scrap rate = Final scrapped units / Units started

Rework is an overlapping activity count: a reworked unit ultimately becomes accepted output, scrap, or open work. Adding the rework count as another physical disposition double counts those units. The EPA's Six Sigma guide distinguishes the material and energy wasted through scrapping defective products from the resources used to repair them.

Build a balanced production table

An illustrative US manufacturer makes the same bracket at two plants. Each input blank represents one potential finished bracket. All units that fail first inspection enter rework in this example; that is a local assumption, not a requirement for other plants.

Put these columns in A:G in Google Sheets. Keep the underlying production-order IDs in your actual file even though the table combines plant and batch for readability.

These are mutually exclusive disposition columns C:F. Recovered good means additional units accepted after rework; it excludes first-pass good. The rework column counts distinct units entering rework, once per unit, rather than every repair operation.

Calculate the measures with exact formulas

Create H:L with the headings below. Enter these formulas in row 2 and fill through row 4:

H2  Accepted output: =C2+D2
I2  First-pass yield: =IF(B2=0,"",C2/B2)
J2  Accepted-output yield: =IF(B2=0,"",H2/B2)
K2  Scrap rate: =IF(B2=0,"",E2/B2)
L2  Rework entry rate: =IF(B2=0,"",G2/B2)

Format I:L as percentages. A blank for zero starts means the rate is undefined, rather than a measured zero. Show two decimal places in the review; retain full precision in the cells.

Calculate total yield from total quantities:

=SUM(H2:H4)/SUM(B2:B4)

The result is 3,850 / 4,000 = 96.25%. Averaging the three displayed batch yields gives 96.00%, which assigns the smaller batches as much weight as Texas B.

For larger exports, sum quantities by plant, product, and batch-start period before dividing. Google documents SUMIFS for sums that meet multiple criteria; use it to select matching rows rather than averaging their percentages. Covirage is not affiliated with Google.

Prove the result before ranking plants

Add a reconciliation column M:

M2  Disposition difference: =B2-SUM(C2:F2)

Each example row returns zero. The company check is:

4,000 started = 3,720 first-pass good + 130 recovered good + 130 final scrap + 20 open work.

Accepted output, scrap, and open work are therefore 96.25%, 3.25%, and 0.50% of starts. Together they account for every input unit. Rework recovery adds 130 / 4,000 = 3.25 percentage points to first-pass yield, while the 20 unfinished units keep the final result provisional.

Texas B has the highest recorded first-pass and accepted-output yields. Ohio A recovers more output through rework than Ohio C, but this table does not contain the hours or costs needed to judge that recovery's economics. Use scrap cost analysis for the financial effect and production analytics to bring recorded labor into the review.

Where it goes wrong

• Counting repair attempts as new units. Multiple repair operations on one bracket do not create additional starts or accepted pieces.
• Calling open work a loss. Ohio C still has unfinished units. Keep them visible and update the batch as dispositions arrive.
• Changing acceptance rules. A relaxed inspection threshold can improve measured yield without improving the product. Quality owns the acceptance definition.
• Comparing different routes. Different products, material grades, or processing steps can explain plant differences. Compare matching cohorts before assigning causes.

Yield measures physical conversion. Overall equipment effectiveness also considers time and speed losses, so a high yield alone cannot establish efficient equipment use.

Do this on your own file in Covirage

Bring a sample of your own production export with starts, accepted quantities, scrap, rework, and open work by plant and product. Covirage maps the columns, and its tools compute and check the figures; the external AI model explains the results with every figure traced to its rows. Create a free Covirage account, which takes about a minute, then set up your business and bring your file.

See Covirage for industrial manufacturers for the wider business context.