Overtime, double shifts and fatigue: setting limits that hold

A double shift rarely looks dangerous at the start. The operator agrees, the supervisor is relieved, the dispatch date is saved. The risk arrives in the last hours. That is when the wrong compound gets weighed, the light curtain is bypassed to save a few seconds, or a tired hand reaches under a press ram.

Overtime itself is not the problem. Plants need it for breakdown recovery, sudden call-offs and seasonal rushes. The problem is overtime that has become the normal way to run the plant, with no limit per person and nobody looking at who is working how long.

• No absence buffer in the manning plan. Every absence is covered by asking someone to stay on.
• Workers depend on it. Once overtime is part of the monthly budget at home, people ask for it.
• It is easier than calling relief. A supervisor at the end of a shift will ask whoever is standing nearby.
• Dispatch dates are fixed, schedules are not. A late casting or a delayed mould trial is recovered on the last two nights.
• Nobody owns the total. Production sanctions it, payroll pays it, and nobody adds it up per person.

Look for patterns, not single events. Near misses and scrap tags bunch up in the closing hours of stretched shifts. The same names appear on the overtime register every week. Weekly offs are swapped so often that some people go many days without one. Overtime stays high even in months when orders are slack. That last sign means the plant is short-staffed and using overtime to hide it.

The pressure looks different by trade. Foundries run furnace campaigns that ignore the calendar, as our melting and moulding page explains. Food plants stretch dawn and night shifts through harvest and festival weeks, covered in our notes on food processors. Module and inverter makers lean on thin night cover for burn-in, described for solar equipment plants.

• Foundries. Relining weekends, furnace campaigns, knockout crews held back to clear a heat.
• Forge shops. Die-change nights and urgent re-forging of rejected batches.
• Rice and flour mills. Paddy arrival weeks when the dryer and sorter run round the clock.
• Snack and sweet units. Frying and packing lines before Diwali gifting orders.
• Pharma. Validation batches and stock-out rushes on the compression floor.
• Corrugation. Festival-season double runs on the corrugator and stitcher.

Fatigue also hides in the time office data. A gate punch at six in the morning and another after midnight on the same card is a double shift, whatever the roster says. Biometric logs, canteen coupons and bus manifests often show long days that the overtime register never captured. Reconcile them once a month for the heaviest sections.

1. 1

   Measure first

   From the overtime register and attendance data, list hours per person per week for the last three months. Sort by the highest totals.

2. 2

   Write the plant's own caps per person

   Set a weekly hours ceiling and a minimum rest gap between shifts. Limit the days in a row without a weekly off. Never let a double shift run into the next morning shift.

3. 3

   Mark the stations where doubles are never allowed

   Furnace tapping and pouring, reactor charging, manual-feed presses, overhead crane and forklift driving, solvent handling. Anyone on these goes home at the end of a full shift.

4. 4

   Sanction before the hours, not after

   Overtime beyond the normal shift needs a slip signed before it starts. Retrospective sanction becomes a rubber stamp.

5. 5

   Offer by rotation

   Keep a list per section and offer overtime in order. It spreads both the money and the tiredness.

6. 6

   Review weekly outside production

   HR or the plant head looks at the top names and any breach of the caps, and asks why.

Date, section and shift: ________.
Name, gate pass number and station: ________.
Reason: breakdown / absence cover / dispatch / other: ________.
Hours requested: from ________ to ________.
Hours already worked this week, including this request: ________.
Last weekly off taken on: ________.
Is the station on the no-double list? Yes / No.
Sanctioned by, before start: ________. Checked by HR or time office: ________.

Caps alone push the problem around unless the plant carries enough people. Build an absence buffer into manning norms for each line, and train a small relief pool to level 2 on the stations that most often need cover. Our roster and time office work writes the rules for rotation, swaps and overtime sanction. The welfare and safety side looks at heat, rest breaks and the stations where fatigue does the most harm.

For the first two months, check three things weekly. Look at breaches of the caps, near misses by hour of shift, and complaints that overtime is shared unfairly. Expect grumbling from people whose household budget leaned on the extra money. A clear rota and honest talk about why help more than exceptions. For night work specifically, see our answer on keeping the night shift productive.

Print last month's overtime by person and circle every name above your intended cap. That list is your first conversation with production. Our plant HR method ties overtime to the manning plan and the skill matrix. For help setting caps and a relief pool, brief us on your sections.