This page is for anyone who has to answer a line-level question: how many pieces could this specific line make in a day, if everything went to plan. Lesson 7.1.3 already showed that a factory can only promise what its remaining capacity allows. This lesson goes one level deeper: it shows how to calculate what that capacity actually is, one line at a time, in minutes and pieces, using the SMV (Standard minute value) already fixed in Track 7. It mainly teaches a decision: whether a manager can answer a capacity question with the figures already at hand, or must calculate more first.
This matters most to a production manager at a factory like Delta Garments, where dozens of lines run different operations, operator counts and shift lengths on a given day. Guessing a line's output from memory, or borrowing a figure from a different line, produces a number unrelated to the line being planned.
Without this calculation, a person mixes up a line's maximum with what it can really deliver, confirming a date the line was never capable of meeting. This lesson gives the method: operators, multiplied by minutes, divided by SMV.
You need: the SMV of the operation a line runs, already introduced as a term in Track 7 (T07-C03-L02). You do not need to have built a capacity booking sheet before.
By the end of this lesson you can:
Not covered here: applying an efficiency percentage to get actual daily capacity (lesson 8.2.2), booking a line's capacity against real orders (lesson 8.2.3), and what happens when a line is booked beyond its capacity (lesson 8.2.4).
| Term | Meaning |
|---|---|
| Standard minute value (SMV) | The standard time, in minutes, a trained operator needs to complete one operation on one piece, used to calculate a line's expected output and workload. |
| Available minutes | The total working minutes a line or an operator has in a given period, before any efficiency loss is applied, calculated as operators multiplied by working minutes per operator. |
| Theoretical daily capacity | The number of pieces a line could produce in a day if every available minute converted directly into output at the operation's SMV, before any efficiency loss is applied. |
| Bottleneck | The one stage in a production flow whose limited output slows down every stage after it, even when every other stage has spare capacity. |
| Capacity | The maximum quantity a factory, a line or a department can produce in a given time, given its current people, machines and hours. |
A line's theoretical daily capacity in pieces is its total available minutes for the day, divided by the SMV of the operation. Total available minutes come from the number of operators on the line multiplied by the working minutes each operator has that day. Dividing that total by the SMV converts minutes of available work into a count of pieces the line could produce if every available minute converted directly into standard output.
Line 1's total available minutes for the day: 60 operators × 480 minutes each.
Line 1's theoretical daily capacity, in pieces: total available minutes divided by the operation's SMV.
A person who has only calculated capacity for one simple line should not assume every line looks the same. The calculation does not change; what feeds into it does.
| What can differ | The shapes you meet | Why it matters |
|---|---|---|
| Single-operation line versus a line running several operations | A line making one simple operation, for example a straight seam, uses one SMV for the whole calculation; a line running a full garment through several operations must use the SMV of its slowest, bottleneck operation. | The bottleneck operation, not any faster operation on the same line, sets the line's real output rate. |
| A shorter shift for a part-day booking | Available minutes per operator falls when a line is booked for only part of a day, for example a half shift, instead of a full day. | Theoretical capacity falls proportionally, even though operator count and SMV stay the same. |
| Export order versus domestic order SMV needs | An export order shaped like Order A needs an accurate SMV per operation to quote a believable delivery date to a buyer such as Northline Apparel; a domestic Make to Stock order for a buyer like Cedar & Co. needs the same calculation, since Cedar & Co.'s own production plan against its sales forecast depends on knowing daily line output. | The calculation does not change between export and domestic; only who is asking for the figure changes. |
| A line with fewer operators than usual | Illness, a transfer, or training removes operators from a line for the day. | Total available minutes, and therefore theoretical capacity, falls, even though the SMV of the operation has not changed at all. |
Karim, production manager at Delta Garments, is asked by Mona whether Line 1 could theoretically produce enough pieces in one day to help cover part of a new enquiry, before either of them checks what is already committed to Order A. Line 1's operator count, available minutes per operator and SMV are illustrative teaching figures, since no line-level headcount or SMV is fixed in the master cast; only Delta Garments' factory-wide total of 600 sewing operators and Order A's own fixed 2-week sewing window are fixed facts.
| Fact | What it tells Karim |
|---|---|
| 60 operators on Line 1 (illustrative) | The headcount to multiply by available minutes, not yet a capacity figure on its own |
| 480 available minutes per operator (illustrative) | A full shift's worth of working minutes for each of those 60 operators |
| SMV of 12.5 minutes for the operation (illustrative) | The standard time one piece takes; needed to convert minutes into pieces |
| What Karim has checked so far | Only the theoretical figure — not Line 1's efficiency, and not its existing bookings against Order A |
This example is illustrative, not a claimed fixed academy fact: with 60 operators on Line 1, each with 480 available minutes in a day, and an SMV of 12.5 minutes for the operation, total available minutes for the day are 60 × 480 = 28,800 minutes. Dividing by the SMV, 28,800 ÷ 12.5 = 2,304 pieces is Line 1's theoretical daily capacity, before any efficiency loss is applied — efficiency is lesson 8.2.2's subject, not calculated here.
A common mistake is using a single operator's SMV-based output rate and simply multiplying it by the number of operators, without first converting to a shared total-minutes figure. This produces the right number only by coincidence, and breaks down the moment operators have different available minutes on the same day, for example a late start, an early finish, or a part shift mixed with full shifts on the same line.
A line's theoretical daily capacity is the most pieces it could make in a day if every minute went perfectly to plan. To find it, count the operators on the line, find how many minutes each one works that day, and multiply the two together to get total available minutes. Then divide total available minutes by the SMV, the standard time one piece takes. If the line runs several operations, use the slowest one's SMV, since that is the one that sets the real pace. This figure is a ceiling, not a promise: it says nothing yet about efficiency losses or about what is already booked to the line.
Karim, production manager at Delta Garments, is asked by Mona, the merchandiser, whether Line 1 could theoretically produce enough pieces in one day to help cover part of a new enquiry, before either of them checks what is already committed to Order A.
Mona's question to Karim:
Can Karim answer Mona's question about theoretical daily capacity using only the operator count, available minutes and SMV, without yet knowing the line's efficiency percentage or its existing bookings?
Yes, for the theoretical figure only. Theoretical daily capacity (2,304 pieces here) is exactly what operators × available minutes ÷ SMV gives, and it needs no efficiency or booking data to calculate.
First, total available minutes must be found before dividing by the SMV. 60 operators × 480 minutes = 28,800 minutes is the figure the SMV divides into, not the operator count or the SMV on its own.
Second, this theoretical figure is not yet the line's real, deliverable output. Efficiency (lesson 8.2.2) and existing bookings (lesson 8.2.3) still have to be applied before Karim or Mona can tell Sara anything about a real delivery date.
Karim can answer Mona's narrow question today. He cannot yet tell her whether Line 1 has spare capacity for the new enquiry.
Skipping the minutes-based calculation and instead guessing a line's daily output from memory, or from a different line's figures, risks a theoretical capacity number that does not match this line's actual operator count or SMV.
If Karim's guess overstates Line 1's theoretical capacity by 10%, the resulting shortfall on a 2,304-piece theoretical day is about 230 pieces (illustrative).
A shortfall of this size surfaces only once the line is already running and committed, when a delivery promise built on the guess falls behind. Against Order A's own FOB price of USD 3.20 per piece, used here only as a benchmark for scale, 230 pieces of unplanned shortfall is a real, avoidable share of a single day's output, not a rounding error a schedule can absorb quietly.
This lesson uses the "Line Daily Capacity" sheet of the course's Capacity booking calculator. Enter operators, available minutes per operator and SMV for the line being checked. The sheet calculates available minutes and theoretical daily capacity automatically in its own columns, ready for lesson 8.2.2 to apply an efficiency percentage to the same row. Download link: the course tool, `templates/T08-C02-capacity-booking-calculator.xlsx`.
1. How is a line's theoretical daily capacity calculated?
2. A line runs several operations end to end. Whose SMV should be used to calculate the line's theoretical daily capacity?
3. A line has 40 operators with 480 available minutes each, and an SMV of 15 minutes. What is its theoretical daily capacity?
| EN | AR | FR | TR | Meaning |
|---|---|---|---|---|
| Standard minute value (SMV) | قيمة الدقيقة المعيارية (SMV) | Valeur minute standard (SMV) | Standart dakika değeri (SMV) | The standard time, in minutes, a trained operator needs to complete one operation on one piece, used to calculate a line's expected output and workload. |
| Available minutes | الدقائق المتاحة | Minutes disponibles | Mevcut dakika | The total working minutes a line or an operator has in a given period, before any efficiency loss is applied, calculated as operators multiplied by working minutes per operator. |
| Theoretical daily capacity | الطاقة اليومية النظرية | Capacité journalière théorique | Teorik günlük kapasite | The number of pieces a line could produce in a day if every available minute converted directly into output at the operation's SMV, before any efficiency loss is applied. |
| Bottleneck | عنق الزجاجة | Goulot d'étranglement | Darboğaz | The one stage in a production flow whose limited output slows down every stage after it, even when every other stage has spare capacity. |
| Capacity | الطاقة الإنتاجية | Capacité | Kapasite | The maximum quantity a factory, a line or a department can produce in a given time, given its current people, machines and hours. |
You now know how to calculate a line's theoretical daily capacity from operators, available minutes and SMV. The next lesson applies an efficiency percentage to that theoretical figure, so it stops being a ceiling and becomes a real, deliverable number. Back to the course map