In an electric arc furnace, minutes are the unit of output. Every minute removed from tap-to-tap time is a minute of furnace capacity returned, yet most of the avoidable minutes are not in the melting itself. They sit in charging gaps, waiting for ladles, sampling delays and turnaround tasks done one after another. Because those delays are short and scattered, they vanish into averages and nobody owns them. A playbook that measures every phase, ranks the delays and fixes the largest ones first turns scattered minutes into a plan. Melt shops that want to see their own cycle broken down can watch a tap-to-tap breakdown built from their own heat records in a short session.
Find the Minutes Hiding Inside Every Tap-to-Tap Cycle
iFactory AI splits each heat into charging, melting, refining, tapping and turnaround, then ranks the delays that cost the most furnace time.
What a Minute Is Worth
Heats per day rise faster than the minutes removed, because the cycle is divided into a fixed day. The columns show an ideal twenty-four hour furnace, and real availability will be lower.
24.0 heats
26.2 heats
28.8 heats
32.0 heats
The Playbook, Phase by Phase
Each phase has its own usual delay and its own first fix. Work down the table and attack the phase with the largest avoidable time.
| Phase | Usual Delay | First Fix | Measure |
|---|---|---|---|
| Charging | Basket not ready, crane busy | Prepare the next basket during melting | Gap between baskets |
| Melting | Low power, unstable arc, waiting for scrap | Match profile to scrap mix | Power-on time per heat |
| Refining | Waiting on sample or temperature | Take readings early and in parallel | Time from end of melt to ready |
| Tapping | Ladle or tap-hole not ready | Stage the ladle ahead of the heat | Wait before tap |
| Turnaround | Tasks done in sequence | Do tasks in parallel | Time from tap to next charge |
See Which Phase Is Costing Your Furnace the Most Time
Book a 30-minute session and iFactory AI will rank phase delays for your own heats, with minutes lost per heat for each cause.
Where the Avoidable Minutes Hide
Once delays are coded and ranked, a few causes usually dominate. The bars show illustrative average minutes lost per heat, and your own ranking will differ. Teams can see a delay ranking on their own furnace in a short walkthrough.
Capturing Delays So They Can Be Ranked
A ranking is only as good as the delay codes behind it. Three steps keep the data honest without burdening the crew.
Turnaround: Parallel Beats Sequential
Between tap and the next charge, four tasks often run one after another. Most can overlap. The chart compares an illustrative window with tasks in sequence and in parallel.
Faster Is Not Always Cheaper
Shortening the cycle helps energy as well, because less time spent waiting means fewer hours of heat loss. But pushing power to gain minutes can raise kWh per tonne if the arc is exposed late in the heat. The cycle and the power profile should be tuned together, which is why both are tracked heat by heat.
A Composite Scenario: A Narrower, Faster Cycle
A melt shop compared tap-to-tap times for twenty heats before and after attacking the top delays. Each pair of columns is one range of minutes, using illustrative counts.
Keeping the Gain
Cycle time creeps back without a routine. Three habits hold the improvement.
Weekly Delay Review
Review the top three causes, agree actions and assign an owner and a due date.
Standard Work by Crew
Write down the fastest crew's sequence and use it as the shared standard.
Escalate Repeats
A delay that returns after a fix gets a deeper review, not another reminder.
Where iFactory AI Fits
Power data, door and charge signals, and heat records already contain the cycle. iFactory AI reads them and turns them into a delay ranking.
Automatic Phase Timing
Every heat is split into phases from signals already in your systems.
Delay Coding
Gaps are detected and confirmed by the crew in one step, then ranked.
Crew Comparison
Compare cycles by crew and shift to find the practice worth copying.
Energy and Time Together
See tap-to-tap and kWh per tonne side by side so neither is traded for the other.
Frequently Asked Questions
How many minutes can we realistically take out?
It depends on where you start. A shop with long, uncoded delays has more room than one already running tight, and a few minutes per heat is a common order of magnitude. The honest answer comes from your own delay ranking, not from a generic range. iFactory AI's team can size the opportunity from a sample of your heat records.
Is a shorter tap-to-tap always better?
Only if the rest of the line can use it. If the caster, ladle supply or scrap yard cannot keep pace, a faster furnace simply waits elsewhere. Shorter cycles also should not come from pushing power that wastes energy or from skipping safety checks. The target is the shortest cycle that the whole process can absorb at stable quality and safe practice.
How do we get reliable delay data without paperwork?
Let the system detect gaps from power, door and charging signals, then ask the crew to confirm the cause from a short list. One tap per delay is realistic, long forms are not. Keep the code list short and unambiguous. See a one-tap delay capture flow in a short walkthrough with your own shift pattern.
Which crews should we learn from?
Compare crews on the same furnace and a similar scrap mix, so differences reflect practice and not conditions. The fastest crew's sequence for turnaround and charging is usually the best source of standard work. Share the comparison openly and ask the crews to explain the differences, since they often know reasons that the data alone cannot show.
How does tap-to-tap connect to kWh per tonne?
Less power-off time means less heat lost between heats, so shorter cycles usually lower kWh per tonne when power is applied well. iFactory AI tracks both measures per heat, so you can see whether a time gain helped or hurt energy. Ask support how time and energy are reported together in the EAF view.
Win Back the Minutes Your Furnace Is Waiting On
iFactory AI ranks every tap-to-tap delay so the biggest minutes get fixed first. Book a walkthrough to see it on your own heat records.
