22.10 Manufacturing

By Ravindra Bagale Last updated: 6 October 2026

Plant interviews around Chakan (Pune) and Ambad (Nashik) ask scrap and whether the line was actually available. "We ran 1,000 pieces" is not a KPI when 300 of them are scrap. These plants are fictional labels for class, not a company's shift report.

OEE (Overall Equipment Effectiveness) needs availability, performance, and quality. This table has the first and the third. Do not invent a performance factor to make OEE look complete.

KPI	What the number means	Who uses it	Action it drives
Availability	(Planned minutes minus down minutes) divided by planned minutes.	Production lead	A long down time is maintenance or material. Do not ask the line for more pieces that hour.
Scrap %	(Total pieces minus good pieces) divided by total pieces.	Quality and production	High scrap stops the line. More output with the same scrap rate wastes material.
Good pieces	Count that passed.	Dispatch	This is what can be shipped. Total pieces cannot.

Fictional sample rows. One shift. Every line was planned for 480 minutes and counted 1,000 pieces so the vanity metric is obvious. Type these rows into a new sheet from cell A1, press Ctrl + T, and name the table tblLines (Table Design › Table Name).

Line	Plant	Planned min	Down min	Good pcs	Total pcs
Line A	Chakan, Pune	480	48	900	1,000
Line B	Chakan, Pune	480	120	700	1,000
Line C	Ambad, Nashik	480	24	950	1,000
Line D	Ambad, Nashik	480	96	800	1,000
Line E	Kolhapur	480	60	850	1,000
Line F	Nagpur	480	30	920	1,000

Excel formulas for the whole file (type them in empty cells below or beside the table):

KPI	Excel formula	Result	Number format
Availability	`=(SUM(tblLines[Planned min])-SUM(tblLines[Down min]))/SUM(tblLines[Planned min])`	86.9%	`0.0%`
Scrap %	`=(SUM(tblLines[Total pcs])-SUM(tblLines[Good pcs]))/SUM(tblLines[Total pcs])`	14.7%	`0.0%`

Calculated columns (one result per row). Click the first empty column of the table, type the header, then the formula. The Table fills every row by itself.

New column	Formula in the first row
Availability	`=([@[Planned min]]-[@[Down min]])/[@[Planned min]]`
Scrap %	`=([@[Total pcs]]-[@[Good pcs]])/[@[Total pcs]]`

Expected result per row:

Line	Availability	Scrap %
Line A	90.0%	10.0%
Line B	75.0%	30.0%
Line C	95.0%	5.0%
Line D	80.0%	20.0%
Line E	87.5%	15.0%
Line F	93.8%	8.0%

Always calculate the file-level KPI as a ratio of totals (SUM ÷ SUM). Do not take the AVERAGE of the per-row percentages; a small row would count as much as a big one.

	Good KPI	Vanity metric
From the same rows	Line B scrap 30.0% and availability 75.0%	Every line's 1,000 pieces
Why	Line B and Line C "produced the same". They did not.	A dashboard of total pieces is a flat bar. It cannot start a maintenance job.

What the manager does. The Pune (Chakan) manager stops Line B and reads the 120 down minutes before the next shift starts. The Nashik (Ambad) manager uses Line C as the standard and looks at Line D, where scrap is 200 ÷ 1,000 = 20.0% and availability is (480 − 96) ÷ 480 = 80.0%. Do not congratulate Nagpur only because 920 good pieces is close to 1,000. Say the scrap: 8.0%.

Ravindra Bagale's Tip

If the file has no performance data, do not write OEE. Show availability and scrap % separately; that is more honest.