Shift scheduling for manufacturing plants

Rotating across A, B and C

The usual pattern moves a worker from A to B to C, one week or one fortnight at a time. Weekly rotation spreads the night shift evenly; fortnightly rotation gives the body clock longer to settle. The rule that matters most is where the changeover falls. Put a weekly off at every change, so no one finishes a C shift at 6 am and is expected back for an A shift the same morning. Publish the roster at least a week ahead, in the app and on the time office notice board.

Worked example: a 21-day cycle for one line

A machining line needs 6 operators on each of the A, B and C shifts. Each operator follows a 21-day cycle: 6 A shifts, a day off, 6 B shifts, a day off, 6 C shifts, a day off. Staff the line with 21 operators and start each one a day later in the cycle than the last. On any day, 6 operators are on A, 6 on B, 6 on C and 3 are off. Each operator works 18 shifts of 8 hours, which is 144 hours in 21 days or 48 hours a week, and every shift change comes after a rest day. The trade-off is that crews mix a little each day; plants that want fixed crews move groups together instead.

Weekly offs: plant day or personal day

Some industrial estates keep a fixed weekday off instead of Sunday, and the whole plant rests that day. Continuous sections such as heat treatment, paint shops and furnaces cannot stop, so their operators get personal weekly offs spread across the week. Mark clearly which lines follow the plant day and which follow a personal day. When that is left to a supervisor's memory, the same worker ends up working 13 days in a row before anyone notices.

Swaps, cover and minimum operators

Swaps are part of plant life. A worker needs a morning free for a child's school admission and trades with a colleague on the B shift. Allow swaps only between people with the same skill, so a CNC setter is not replaced by a helper, and let the roster change only after the supervisor and HR approve. Fix a minimum for each line and shift, including at least one trained first-aider, and check it before approving any swap.

How to set it up in ZeniaHR

1. In Shifts & Roster, set A 6 am to 2 pm, B 2 pm to 10 pm, C 10 pm to 6 am and General, each with its break, full-day and half-day hours.
2. Create a rotation template for each line, such as the 21-day cycle above, and stagger it per person so coverage stays even.
3. Set weekly off patterns per shift for lines that follow the plant day off, and personal weekly offs for continuous sections.
4. Assign rosters in bulk for up to 92 days and check the day grid for thin shifts before publishing.
5. Turn on Shift Swaps so workers ask colleagues in the app, and the roster changes only after supervisor and HR approval.
6. At each shift start, open the live board filtered by department and shift to spot empty machines before the line starts.

Read more about shifts and rosters in ZeniaHR.

Roles this applies to

Frequently asked questions