This page teaches how a utility submeter on a specific line or department gives its own consumption baseline and consumption intensity, where a single monthly bill covering an entire factory cannot. This is mainly a process decision, made whenever an order's own environmental footprint must be reported or verified rather than assumed. An agent or buyer that accepts a factory's guessed share of its own whole-factory bill, based on floor space or headcount, risks reporting a figure that understates or overstates the true energy or water cost of a specific order's own line.
A factory that never installs a submeter can only guess how its own overhead, including energy and water, splits between an export line running Make to Order and a domestic line running Make to Stock. A guess based on floor space assumes energy use tracks floor space evenly, which is rarely true once machine type, shift pattern and line speed differ between lines.
You need: a factory's own whole-factory utility bill, and either a submeter reading for the specific line in question or a stated basis for a guessed allocation.
By the end of this lesson you can:
Not covered here: identifying a genuine automation candidate (Lesson 4.1) and comparing its own cost against labour cost (Lesson 4.2), and building the complete decision tool (Lesson 4.4).
| Term | Meaning |
|---|---|
| Overhead | A factory's running costs that are not fabric, trims or direct labour: rent, electricity, management salaries and similar costs, shared across all the pieces it makes. |
| Utility submeter | A separate meter installed on one line, department or machine group, measuring its own electricity or water use apart from the factory's single main meter. |
| Consumption baseline | The energy or water use a submeter records for a line over a stated period, used as the starting figure for tracking or comparison. |
| Consumption intensity | A line's own energy or water use divided by the pieces it produced over the same period, giving a per-piece figure comparable across orders. |
| Guessed allocation | An estimate of how much of a whole-factory utility bill belongs to one line, based on an indirect measure such as floor space or headcount, not a direct reading. |
A utility submeter installed on one line gives its own consumption baseline directly, the actual energy or water it used over a stated period. Dividing that baseline by the pieces the line produced in the same period gives its own consumption intensity, a per-piece figure that can be tracked over time or compared against another order. A guessed allocation, based on an indirect measure like floor space, is not the same figure and can differ from the true submetered reading by a meaningful margin.
| What can differ | The shapes you meet | Why it matters |
|---|---|---|
| Export MTO line vs. domestic MTS line | An export MTO line like Order A's own line can run intensive equipment at a steady pace for a long unbroken run; a domestic MTS line restocked in smaller batches can start and stop more often, using energy less evenly across the month | Floor-space or headcount guesses assume even use, but MTO and MTS lines within the same hybrid factory rarely use energy at the same steady rate |
| Hybrid model, shared utility connections | A factory like Delta Garments running MTO and MTS lines side by side often shares one electricity connection and one water main, making a single whole-factory bill the only figure available unless submeters are installed line by line | Without submeters, a hybrid factory has no reliable way to state which of its own lines is responsible for how much of its total energy or water use |
| Wet processing vs. dry processing stages | A stage using wet processing, such as dyeing or washing, uses far more water per piece than a dry stage like cutting or sewing | Guessing water allocation by floor space badly understates a wet-processing area's own true water use relative to its physical size |
| Season and shift pattern | A factory running extra shifts during a peak season draws more energy per day than its own off-season baseline, even on the same line | A consumption baseline recorded once, without noting the season or shift pattern behind it, can mislead a later comparison |
| Product families | The same submeter, consumption baseline and consumption intensity method applies whether the goods are apparel, socks and hosiery, knit-to-garment, terry and towels, or home textiles and bedding | An agent new to this method applies the same direct-reading approach regardless of product family |
Delta Garments runs Order A's own export line, 15,000 T-shirts made to order for Northline Apparel, alongside its own domestic Make to Stock lines, a hybrid model. Before this lesson, Delta Garments had only ever guessed the export line's own share of its single whole-factory electricity bill, estimating it at 30% of the total based on the export line's own share of floor space. Meridian Sourcing, the agent representing Northline Apparel, asks Karim to install a utility submeter on the export line to check whether that 30% guess was close to the line's own true use.
Delta Garments' whole-factory electricity bill is USD 8,000 a month for 10,000 kWh across all lines combined, giving an electricity price of about USD 0.80 per kWh. The new submeter on the export line records 4,000 kWh for the month, its own direct consumption baseline, once installed.
The worked numberThe floor-space guess understated the export line's own true electricity cost by USD 800 a month, because the export line's own equipment and steady MTO run pace use more electricity per square metre than the domestic MTS lines it shares floor space with. The submeter's own consumption baseline, 4,000 kWh, gives a consumption intensity of 0.267 kWh per piece on Order A, a figure that can now be tracked or compared against future orders on the same line.
A common mistake is keeping an old guessed allocation in a report because it is already familiar, even after a submeter's own direct reading shows a different, more accurate figure. This under-reports or over-reports a specific line's own true energy or water footprint, which can matter when a buyer or auditor relies on that figure. The fix is replacing the guessed allocation with the submetered reading as soon as it becomes available, and noting the change rather than quietly keeping the old figure.
A single electricity or water bill covering a whole factory cannot say how much of it belongs to one specific line, especially when that factory runs more than one kind of order side by side. A separate meter on just that line gives its own real number, which can then be divided by how many pieces it made to give a per-piece figure worth tracking. At Delta Garments, guessing the export line's own share by floor space alone said USD 2,400 a month, but a real meter on the line showed USD 3,200, a gap of USD 800 a month that guessing alone would never have caught.
Sara, the buyer at Northline Apparel, sees Delta Garments' sustainability report still showing the export line's electricity use as 30% of the whole-factory bill, USD 2,400 a month, and asks Meridian Sourcing whether that figure can still be reported now that a submeter has been installed. The facts in front of Meridian Sourcing:
The question relayed to Meridian Sourcing:
Should the old 30% floor-space guess still be reported now that a submeter reading is available? Decide before you open the decision.
No, the old 30% floor-space guess should not still be reported; the submetered reading of USD 3,200 is the export line's own true figure.
Two facts decide this. First, this lesson's rule states a submeter's own direct consumption baseline is the true figure, and a guessed allocation should be replaced once a submetered reading is available, not kept for familiarity. Second, the USD 800 gap between the guessed USD 2,400 and the submetered USD 3,200 is not small relative to the guessed figure itself, understating the export line's own true electricity cost by exactly a third.
Continuing to report a guessed allocation once a more accurate submetered reading exists ignores exactly the gap this lesson exists to catch.
An USD 800 monthly understatement, if never corrected, compounds to USD 9,600 understated across a full reporting year, a gap that could affect how Northline Apparel reports its own supply chain's energy footprint to its retail customers, including Fairway Stores. Correcting the figure once the submeter is installed avoids this recurring understatement entirely.
Use the T26-C04 Automation and environmental monitoring decision tool. Enter the whole-factory bill, the submeter's own reading and the pieces produced; the sheet calculates the consumption intensity and flags the gap against any guessed allocation already on file.
[Download the Automation and environmental monitoring decision tool](../../templates/T26-C04-automation-and-environmental-monitoring-decision-tool.xlsx)
Download the Automation and environmental monitoring decision tool (Excel)
1. Why did Delta Garments' 30% floor-space guess understate the export line's own true electricity cost?
2. A submeter records 6,000 kWh on a line that produced 20,000 pieces in the same period. What is that line's own consumption intensity?
| EN | AR | FR | TR | Meaning |
|---|---|---|---|---|
| Overhead | التكاليف العامة | Frais généraux | Genel giderler | A factory's running costs that are not fabric, trims or direct labour: rent, electricity, management salaries and similar costs, shared across all the pieces it makes. |
| Utility submeter | عداد فرعي للمرافق | Sous-compteur d'utilité | Yardımcı hizmet alt sayacı | A separate meter installed on one line, department or machine group, measuring its own electricity or water use apart from the factory's single main meter. |
| Consumption baseline | خط أساس الاستهلاك | Référence de consommation | Tüketim referans değeri | The energy or water use a submeter records for a line over a stated period, used as the starting figure for tracking or comparison. |
| Consumption intensity | كثافة الاستهلاك | Intensité de consommation | Tüketim yoğunluğu | A line's own energy or water use divided by the pieces it produced over the same period, giving a per-piece figure comparable across orders. |
| Guessed allocation | تخصيص تقديري | Allocation estimée | Tahmini dağıtım | An estimate of how much of a whole-factory utility bill belongs to one line, based on an indirect measure such as floor space or headcount, not a direct reading. |
You now know how to identify a genuine automation candidate, compare its own cost against the labour cost it replaces, and monitor a factory's own energy and water use accurately. The final lesson brings all three decisions together into one complete tool. Back to the course map