What do your changeovers cost a year?

A changeover is the time between the last good part of one job and the first good part of the next: die change, mould change, SKU change, colour change, style change. The machine and its crew are paid for but nothing sellable comes out. Twenty-five changeovers a week at 55 minutes each add up to more than 1,100 machine-hours a year. This calculator turns your changeover count and average duration into hours and rupees a year, and shows what a target reduction would free up.

How the calculator works

The calculator takes five inputs:

• Changeovers per week. Count every job, SKU, die, mould, colour or style change on the machine or line.
• Average changeover (minutes). From the last good part of the old job to the first good part of the new one, including first-piece approval and adjustment, not just the time the tool is being swapped.
• Machine or line hour rate incl. crew (₹/h). What an hour of the machine or line costs, plus the setter and helpers who work on the change. The machine hour rate calculator shows how to build the machine part.
• Target cut (%). How much shorter you think each changeover could be. This is your own estimate.
• Working weeks a year.

The formulas:

Changeover hours per year = changeovers per week × average minutes ÷ 60 × working weeks
Changeover cost per year = changeover hours × hour rate
Freed by the target cut = changeover cost × target cut

Worked example (India)

A power-press and moulding shop in Haryana running short batches. All figures are assumptions for illustration and match the calculator's defaults, except the wage floor, which comes from Haryana's minimum wage order.

Where ₹1,200 an hour comes from. We assume ₹900 an hour for the machine itself (see the machine hour rate calculator for how to build it) plus a crew of three on the change. Haryana's semi-skilled basic minimum from 1 April 2026 is ₹16,780.74 a month (₹645.41 a day; Haryana Labour Department notification No. 2/25/26-2 Lab of 9 April 2026, Haryana Government Gazette copy), about ₹81 an hour over 208 hours (26 days × 8 hours). With an assumed 25% on top for employer contributions and bonus, each crew member costs about ₹100 an hour, and three cost about ₹300. ₹900 + ₹300 ≈ ₹1,200 an hour. Setters are usually paid above the floor, so use your own payroll figure.

A 30% cut takes the average change from 55 to about 38.5 minutes and returns roughly 344 machine-hours a year. On a shop running two 8-hour shifts six days a week (96 hours a week, an assumption), 22.9 hours of changeover is almost a quarter of the week.

The SMED method behind the "target cut"

SMED (single-minute exchange of die) was developed by Shigeo Shingo in Japan in the 1950s and 1960s. The Lean Enterprise Institute defines it as "a process for changing over production equipment from one part number to another in as little time as possible", with a target of a single-digit number of minutes, under 10. The core idea is to separate internal work, which can only be done with the machine stopped, from external work, which can be done while it is still running, and then to move as much as possible to external: dies pre-heated and staged, tools and bolts ready on a cart, settings recorded instead of found by trial.

You do not need to reach single minutes for the method to pay. In practice, the first gains usually come from external preparation that costs almost nothing: the next die waiting at the press, the crane booked, the first-piece inspector told in advance.

What typical numbers look like

• Published SMED results. A peer-reviewed action-research study of SMED in three garment factories in developing countries reports changeover time cut by 50% to 64% (Mohammad, Hamja and Hasle, International Journal of Lean Six Sigma, 2024). A case study from a small-scale unit in northern India describes the same approach, removing unnecessary steps and moving internal work to external, but its abstract gives no single percentage (Singh, Singh and Singh, Benchmarking, 2018). These are individual case studies, not industry averages, and published cases tend to be the successful ones. Against them, the calculator's 30% default is deliberately conservative.
• Typical changeover times in Indian plants. We found no credible public survey of average changeover duration or changeovers per week by industry in India. They depend heavily on the product mix. Measure your own over two or three weeks.

What this number does not tell you

• Whether freed hours become money. The ₹ figure is real only if the freed hours turn into output you can sell, or into shorter overtime. On a machine that already waits for orders or for the bottleneck, shorter changeovers save little cash. Often the better use is to run smaller batches and hold less stock, which is worth money in a different way.
• Material lost at start-up. Scrap and trial parts made while the new job is being adjusted are not counted. On presses, moulding machines and printing lines they can be a large share of the real cost; the rework cost calculator can price them as scrap.
• Whether your average is right. Changeovers are rarely timed end to end. Logbooks often record the tool swap and miss the waiting for the crane, the die, the setter or first-piece approval, which is where a lot of the time goes.
• How the crew's time is spent. A rupee total does not say which steps are internal and could be done in advance. That needs a video of real changeovers or a stopwatch study.
• What a camera can and cannot see. A camera can show when a machine stopped for a change and when it started making parts again, and how long it stood waiting with nobody at it. It cannot tell whether the first part is within tolerance or why a setter was called away. Mama looks at machines and changeover duration, not at individual workers; any camera use on the floor needs a worker notice under DPDP.

Related guides

• Die Change Time on Power Presses: What a 70-Minute Change Costs an Indian Press Shop (₹)
• SKU Changeover on Indian Packing Lines: Where the Hours Go
• Cameras in Injection-Moulding Units: Short Shots, Cycle Drift and Mould Changes
• Cameras in Packaging and Printing Plants: Waste, Make-Ready and Job Changeovers
• OEE Explained for Indian Factories (with a Rupee Example)
• OEE calculator

FAQ

How do you calculate the cost of changeover time? Multiply changeovers per week by the average minutes, divide by 60 and multiply by working weeks to get hours a year. Multiply that by the hourly cost of the machine and crew. For 25 changeovers of 55 minutes over 50 weeks at ₹1,200 an hour, that is 1,146 hours and ₹13.75 lakh a year.

What counts as changeover time? From the last good part of the old job to the first good part of the new one. That includes waiting for the die or mould, adjustment and first-piece approval, not only the time spent swapping tools.

What is SMED? Single-minute exchange of die, developed by Shigeo Shingo. It aims to bring changeovers under 10 minutes by moving as much work as possible to while the machine is still running and simplifying what remains.

How much can SMED reduce changeover time? Published case studies report large cuts; one peer-reviewed study of three garment factories reports 50–64%. Results vary by machine and starting point, so the calculator's 30% default is a conservative assumption, not a promise.

Should I include the crew's wages in the changeover cost? Yes. The setter and helpers are paid for the whole change while the machine produces nothing. In the worked example above the machine part (₹900 an hour) is three times the crew part (₹300), but in labour-heavy changeovers the crew share can be larger, so use your own figures.

Want this measured on your own floor instead of estimated? Leave an email or phone in the form below.