This page is for a merchandiser or production manager who already knows a line's own target pace but has never turned a real shift's own output log into an actual efficiency figure. At work, a manager who plans against an assumed efficiency figure, quoted from memory rather than the shift that just ran, has no way of knowing whether the line is actually behind, on pace, or ahead until a deadline is already close. This lesson mainly teaches the money flow: it shows how to calculate a line's own real efficiency from its own target and actual output.
Cedar & Co. reorders 5,000 T-shirts from Delta Garments against its own forecast, on 60-day open account, similar in construction to Order A's own range. Delta Garments assigns the reorder to a line with its own target pace of 150 pieces per hour across an 8-hour shift, giving a target output of 1,200 pieces. Karim, the production manager, has quoted the line's own efficiency as "around 85%" from memory for weeks. Without calculating the actual figure from a real output log, nobody at Delta Garments can say whether that assumption is still true.
You need: no previous lesson from this track, though lesson T26-C03-L01's own habit of naming one real question is useful background for deciding when an efficiency figure needs checking.
By the end of this lesson you can:
Not covered here: building a dashboard around one real question, covered in lesson T26-C03-L01, and deciding which shop-floor metric predicts a late shipment, covered in lesson T26-C03-L03.
| Term | Meaning |
|---|---|
| Line efficiency | A line's own actual output in a period, divided by its own target output for the same period, expressed as a percentage. |
| Target pace | The number of pieces a line is expected to produce per hour, set from its own known operations and staffing. |
| Target output | A line's own target pace multiplied by its own run time, giving the output the line is expected to reach over a shift or period. |
| Actual output | The real number of pieces a line produced in a period, counted from its own output log rather than assumed. |
| Assumed efficiency | An efficiency figure quoted from memory or habit, not calculated from a specific period's own real output data. |
| Efficiency gap | The difference between a line's own target output and its own actual output for the same period. |
| Run time | The hours a line actually operates in a period, used with target pace to calculate target output. |
The general rule is to calculate a line's own efficiency directly from two real figures for the same period: its actual output, counted from the shift's own output log, divided by its target output, calculated from its own target pace multiplied by its own run time. An efficiency figure quoted from memory, without this calculation behind it, is an assumption, not a measurement, and should never be treated as one.
| What can differ | The shapes you will meet | Why it matters |
|---|---|---|
| Domestic Make to Stock reorder on a familiar style | Cedar & Co.'s reorder runs on a line already trained on a similar style to Order A's own range, so its own target pace is set from established data. | A familiar style gives a reliable target pace to calculate target output from, unlike a brand-new style with no run history. |
| Export Make to Order with a fixed shipment date | A line producing Order A itself for Northline Apparel has its own target pace set tightly against the order's own 16-week timeline, since a shortfall has a fixed port cut-off behind it. | The same efficiency formula applies, but the consequence of a gap is more urgent when a fixed date, not just a forecast, sits behind the target. |
| Hybrid line switching between two styles in one shift | A line producing Cedar & Co.'s reorder for part of a shift and an export style for the remainder needs its own target output split by style, not one blended figure for the whole shift. | Blending two styles' own target paces into one shift-wide figure hides which style is actually running below its own target. |
| New line or new operator group with no run history | A line newly assigned to a style, without an established target pace, has to use a provisional target pace until enough real shifts confirm it. | A provisional target treated as final can make a genuinely improving line look permanently inefficient, or a genuinely struggling line look acceptable. |
Karim assigns Cedar & Co.'s 5,000-piece reorder to a line with a target pace of 150 pieces per hour over an 8-hour shift. Mona asks for the line's own actual efficiency on yesterday's shift before Cedar & Co.'s next planning call, rather than the "around 85%" figure Karim has been quoting from memory.
The line's own actual efficiency works out to 79.2%, 5.8 percentage points below the 85% Karim had been quoting from memory. On this real figure, the line is producing 250 fewer pieces than its own target output for the shift, a gap that stayed invisible as long as the assumed figure went unchecked against an actual output log.
A common mistake is a production manager repeating a round efficiency figure, such as "around 85%", across weeks or months without recalculating it from each shift's own actual output log. The figure feels safe precisely because it has already been said before, many times, which is exactly why nobody stops to check it carefully against a real output log until a deadline forces the question. What this costs is real: Delta Garments' planning for Cedar & Co.'s reorder assumed a target output that the line, at its own real 79.2% efficiency, cannot actually reach, a gap of 250 pieces per shift that compounds daily until someone calculates the actual figure and discovers the reorder is running behind its own forecast.
A line's own efficiency is simply how much it actually produced compared to how much it was expected to produce over the same hours, and the only reliable way to know that figure is to calculate it from a real shift's own output count, not to repeat a number remembered from an earlier period. Multiplying a line's own target pace by its own run time gives the target it should have reached; dividing what it actually produced by that target gives the real efficiency figure. A round number quoted from habit can drift a long way from that real figure without anyone noticing, until someone finally checks it against an actual shift.
Cedar & Co.'s planning call is tomorrow, and Karim is preparing his usual update, "the line's running at about 85%, we're on track", the same line he has used in every update for the past two months. Mona asks him to check yesterday's own output log before repeating that figure.
Should Karim send this update without first calculating yesterday's own actual efficiency? Decide before opening the answer.
No, not without calculating the real figure first. An efficiency figure repeated from memory across two months of updates is an assumption, not a measurement of any specific shift.
First, yesterday's own actual output log gives a real efficiency of 79.2%, not 85%, a gap of 5.8 percentage points that changes whether the reorder is genuinely on track.
Second, at 79.2% efficiency the line is producing 250 fewer pieces per shift than its own target output, a shortfall that, left uncorrected, will make Cedar & Co.'s reorder late against its own forecast even though every previous update called it on track.
Karim should calculate the actual efficiency from yesterday's own output log before sending any update, and if the real figure is genuinely below what the reorder's own timeline needs, report the gap honestly rather than repeating the familiar 85% figure out of habit.
At the line's own real rate of 950 pieces per shift, Cedar & Co.'s 5,000-piece reorder needs about 5.3 shifts, not the roughly 4.2 shifts the assumed 85% figure would have implied. That extra shift, uncaught until someone calculates the actual efficiency, is exactly the kind of gap lesson T26-C03-L03 shows how to catch before it turns into a late shipment.
Open the course workbook's "Line efficiency" sheet. Enter the line's own target pace, run time, and actual output for the period; the sheet calculates target output and real efficiency with a live formula, and flags any gap against an assumed figure entered for comparison.
[Download the Dashboards and shop-floor analytics worksheet](../../templates/T26-C03-dashboards-and-shop-floor-analytics-worksheet.xlsx)
Download the Dashboards and shop-floor analytics worksheet (Excel)
1. A line has a target pace of 150 pieces per hour and runs an 8-hour shift, producing 1,020 pieces. What is its own line efficiency?
2. A production manager has quoted a line's own efficiency as 'around 85%' for two months without recalculating it. What is the most likely risk?
| EN | AR | FR | TR | Meaning |
|---|---|---|---|---|
| Line efficiency | كفاءة الخط | Efficacité de la ligne | Hat verimliliği | A line's own actual output in a period, divided by its own target output for the same period, expressed as a percentage. |
| Target pace | الوتيرة المستهدفة | Cadence cible | Hedef tempo | The number of pieces a line is expected to produce per hour, set from its own known operations and staffing. |
| Target output | الناتج المستهدف | Production cible | Hedef üretim | A line's own target pace multiplied by its own run time, giving the output the line is expected to reach over a shift or period. |
| Actual output | الناتج الفعلي | Production réelle | Gerçek üretim | The real number of pieces a line produced in a period, counted from its own output log rather than assumed. |
| Assumed efficiency | الكفاءة المفترَضة | Efficacité supposée | Varsayılan verimlilik | An efficiency figure quoted from memory or habit, not calculated from a specific period's own real output data. |
| Efficiency gap | فجوة الكفاءة | Écart d'efficacité | Verimlilik farkı | The difference between a line's own target output and its own actual output for the same period. |
| Run time | زمن التشغيل | Temps de fonctionnement | Çalışma süresi | The hours a line actually operates in a period, used with target pace to calculate target output. |
You now know how to calculate a line's own real efficiency. The next lesson shows which shop-floor metric, efficiency included, actually predicts a late shipment before it happens. Back to the course map