# Shop Order Lead Time Calculator (IFS Manufacturing)

> Source: https://netray.co/tools/ifs-shop-order-lead-time-calculator
> Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems.
> Section: Free Tools

## Short answer

Estimate how long a shop order really takes through its routing, and what share of that time is actual work, as a check on lead times stored in IFS.

## Category

other-erp

## Erp

IFS Cloud

## Industry

Discrete Manufacturing

## Audience

- Production planner
- Scheduler
- Manufacturing engineer

## Tool

**Kind:** calculator

**Inputs:**

#### Order quantity

**Key:** qty

**Type:** slider

**Default:** 250

**Min:** 1

**Max:** 2000

**Step:** 1

**Unit:** units

#### Number of operations

**Key:** ops

**Type:** number

**Default:** 3

**Min:** 1

**Max:** 20

**Step:** 1

**Unit:** ops

**Help:** This model assumes similar setup and run per operation.

#### Setup time per operation

**Key:** setup_hours

**Type:** number

**Default:** 2.5

**Min:** 0

**Step:** 0.25

**Unit:** hours

#### Run time per unit per operation

**Key:** run_min

**Type:** number

**Default:** 4.2

**Min:** 0

**Step:** 0.1

**Unit:** minutes

#### Run efficiency

**Key:** eff

**Type:** number

**Default:** 85

**Min:** 10

**Max:** 120

**Step:** 1

**Unit:** %

**Help:** Actual speed relative to standard.

#### Available hours per working day

**Key:** hours_per_day

**Type:** number

**Default:** 7.5

**Min:** 1

**Max:** 24

**Step:** 0.5

**Unit:** hours

**Help:** Productive hours at the work center, per day.

#### Average queue time per operation

**Key:** queue_days

**Type:** number

**Default:** 2

**Min:** 0

**Step:** 0.5

**Unit:** days

#### Move and wait time per operation

**Key:** move_days

**Type:** number

**Default:** 0.5

**Min:** 0

**Step:** 0.25

**Unit:** days

**Outputs:**

#### Run hours per operation

**Key:** run_hours

**Expr:** qty * run_min / 60 / (eff / 100)

**Format:** hours

#### Total hours per operation

**Key:** op_hours

**Expr:** setup_hours + run_hours

**Format:** hours

#### Touch time in working days

**Key:** touch_days

**Expr:** ops * op_hours / hours_per_day

**Format:** days

#### Total lead time

**Key:** lead_time

**Expr:** touch_days + ops * (queue_days + move_days)

**Format:** days

**Primary:** true

**Description:** Touch time plus queue and move across all operations.

#### Touch time share of lead time

**Key:** touch_pct

**Expr:** touch_days / lead_time * 100

**Format:** percent

**Primary:** true

**Description:** Low values show that waiting, not work, drives lead time.

#### Lead time per unit

**Key:** per_unit_days

**Expr:** lead_time / qty

**Format:** decimal

**Chart:**

#### Lead time vs order quantity

**Type:** line

**X:** qty

**From:** 10

**To:** 1000

**Steps:** 30

**Series:**

- lead_time
- touch_days

**Disclaimer:** Simplified single-resource model with no overlap between operations. Real scheduling depends on finite capacity, calendars and priorities.

## Content

**Intro:** Planned lead time in an ERP routing is only as good as its inputs. This calculator breaks a shop order into touch time and waiting so you can test whether the lead time your system assumes is credible.

**Sections:**

#### How to use it

**Body:** Enter the order quantity, the number of operations, and the setup and run time for a typical operation. Add run efficiency to reflect how fast people and machines actually work compared with standard. Then enter the available hours per working day at the work center, and the average queue and move times per operation. The result is total lead time in working days and the share of that time that is real work. Use the chart to see how larger lots lengthen lead time.

**Bullets:**

- Take queue times from actual order history
- Use one shift's productive hours unless you run more
- Average operations if routings differ greatly
- Compare the answer with the lead time on the item

#### The calculation

**Body:** Run hours per operation equal quantity times run minutes per unit divided by 60, then divided by efficiency. Setup is added without an efficiency adjustment. Touch days are operations times hours per operation divided by available hours per day. Lead time is touch days plus operations times queue and move days. Touch share is touch days divided by lead time. The model assumes each operation waits for the previous one to finish completely, with no overlap or splitting.

#### Reading the result

**Body:** In many job shops the touch share is in single digits to low double digits, meaning an order spends most of its life waiting. That finding changes where you act: shaving run time by five percent barely changes lead time, while cutting queues through load levelling or smaller releases changes it a lot. If the answer is far from the lead time held on the item, material planning is working from the wrong number and will release orders too early or too late.

#### Common mistakes

**Body:** Using calendar days instead of working days mixes units. Treating standard run time as actual ignores efficiency loss, scrap and rework. Forgetting that large quantities lengthen the run, so one fixed lead time per item hides a quantity effect. Finally, queue time is not a constant: it grows sharply as work center utilization approaches full, so test a busy-period queue as well as an average one.

**Cta:** Netray can help compare lead times stored in your ERP with what shop orders actually took, using your own order history. Ask if you would like to see how.

**Faq:**

#### Does this match IFS scheduling?

**Answer:** No, it is a simplified estimate for sense-checking. IFS scheduling can use finite capacity, calendars and overlap, which this model ignores. Use it to test whether stored lead times are reasonable, not to replace scheduling.

#### What is a good touch time share?

**Answer:** It varies by process. Highly flow-oriented lines show high shares, job shops often show low ones. The useful comparison is your own trend over time and against the share you would need to hit delivery promises.

#### How do I get queue time?

**Answer:** Compare order release or previous operation completion dates with the start of the next operation across a sample of recent shop orders. Average by work center, and separate busy and quiet periods.

#### Why does lead time grow with quantity?

**Answer:** Because run hours scale with units while setup is fixed. Larger orders amortize setup better per unit but occupy each work center longer, which is why lot sizing and lead time are linked.

## Search terms

shop order lead time calculator, manufacturing lead time formula, IFS shop order lead time, routing lead time calculation, queue time setup time run time, touch time ratio, production lead time calculator, MRP lead time accuracy

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