|
If you're thinking about
adopting a different shift length, there are five things you should be familiar
with: (1) the impact on days off, (2) the impact on weekends off, (3) the
staffing requirements, (4) the distribution of the workload, and (5) health and
safety issues.
Days Off
Many workers prefer to work more hours each day in order to get more days off.
They may hate working the longer shifts, but they love the extra days off. The
graph below shows the annual scheduled days off associated with the three most
common shift lengths:
Supporting information:
8-hour shifts: Days off are based on 4-crew schedules (91 days
off/year).
10-hour shifts: Days off are based on 5-crew schedules (146
days off/year).
12-hour shifts: Days off are based on 4-crew schedules (182 days
off/year)
Weekends Off
Increasing the number of weekends off is a common reason for adopting longer
shifts, though there are other schedule features that also affect weekends off.
The graph below shows the maximum possible number of weekends off per year with
the three common shift lengths:
 .
Supporting information:
8-hour shifts: Weekends off are based on 4 crews working 7 consecutive days
(13 weekends off/year).
10-hour shifts: Weekends off are based on 5 crews working 3 and 4 days in a
row (21 weekends off/year).
12-hour shifts: Weekends off are based on 4 crews under a variety of
configurations (26 weekends off/year).
Notes on days and weekends off:
(1) All schedules average 42 hours of work per week.
(2) Figures are based on level coverage (the same number of employees
working on every shift).
(3) The actual number of weekends off depends on more than just shift length. Other
factors are the number of days worked in a row, the pattern of on-off
work days, and the day the pay week begins.
Staffing Requirements
For 24/7 operations that require the same number
of workers on every shift, 8-hour and 12-hour schedules have identical
staffing requirements. Most 10-hour shift schedules require 25 percent more personnel
because you are staffing for 30-hour days (three 10-hour shifts).
The graph below shows the staffing requirements for one person working on every
shift. If you need 5 people on each shift, you simply multiply these figures by
5.
|
Supporting calculations:
8-hour shifts: 1 employee * 3 shifts * 8 hours/shift * 7 days/week / 40
hours/week = 4.2 total employees
10-hour shifts: 1 employee * 3 shifts * 10 hours/shift * 7 days/week /
40 hours/week = 5.25 total employees
12-hour shifts: 1 employee * 2 shifts * 12 hours/shift * 7 days/week / 40
hours/week = 4.2 total employeesNotes
on staffing requirements:
Staffing requirements (e.g., the 4.2 people needed for 8-hour shifts) can be handled
by either of the following:
(1) 4 full-time employees plus an average of 2 hours of overtime per employee
every week. The overtime is built into the schedule to ensure proper coverage at
all times.
(2) 5 full-time employees
with no built-in overtime. The "extra" person would be
used to eliminate overtime and to cover for absences such as vacations, illness,
training, etc.
Workload Distribution
If your workload is relatively constant
throughout the day, you need the same number of employees working at all
times. A steady workload distribution like this is best suited for
8-hour or 12-hour shifts. 10-hour shifts would only work if you could
get by working 20-hours a day (two 10-hour shifts). The 4-hour gap could
be used for maintenance or down time. If you tried to cover the entire
day with 10-hour shifts, you would have 6 hours of overlap. This means
double coverage for 6 hours every day of the week and a 25% increase in
your staffing requirements.
On the other hand, if your work volumes are not constant
throughout the day, the best shift length depends on the magnitude and
duration of your busy periods. Many organizations define the workload
according to their current shift length. For example, "We need two
people from 7 a.m. to 3 p.m., four people from 3 p.m. to 11 p.m., and
one person from 11 p.m. to 7 a.m." A preferable approach is to look at
the workload in one-hour increments to identify the actual duration of
the busy and slow periods. It may turn out that a combination of
different shift lengths is the best match with your workload.
Health and Safety Issues
Anyone who has spent time researching the impact of longer shifts on
employee health and safety will surely be confused by the conflicting
results. Some articles say that after 8 hours alertness and
productivity start to decline. Others say that productivity increased
after workers changed to 12-hour shifts.
The confusion stems from comparing dissimilar situations. Researchers
may have compared one group on an 8-hour fixed shift schedule
with another group on a 12-hour rotating shift schedule. They
didn't factor in different schedule variables,
such as the on-off work pattern, the amount of overtime, shift start
times, and so on. They also did not consider worker characteristics or
the work environment. Problems they attribute to working longer shifts
may be the result of these other factors in combination with the shift
length.
Based our experience with organizations that have adopted longer shifts, we have not found problems as long as the schedule is well designed, with sufficient time off
and reasonable limits on the number of consecutive days worked. There
are some jobs that are not suited to longer shifts (such as tedious
detail inspections). Jobs with exposure to extreme heat, loud noises,
toxins or heavy physical labor may simply be too much to endure for more
than 8-hours.
While longer shifts are certainly popular nationwide, they are not the
unanimous preference of all shiftworkers.
Shiftworkers that are
older, have childcare concerns, are going to school, have second jobs,
or participate in other non-work activities on workdays often prefer
8-hour and 8&12-hour shift schedules. For your employees to make the
right choice on shift length, they should be given a clear understanding
of what they are getting into and what patterns are available. When
employees are involved in the decision to adopt longer shifts, they are
much more likely to support the change.
Here are a couple of research citations for those of you inclined to
read these things:
Caruso CC (2006) Possible broad impacts of long work hours.
Industrial Health 44 (4): 531-36.
Dembe AE, Erickson JB, Delbos RG, and Banks SM (2005) The impact of
overtime and long work hours on occupational injuries and illness: new
evidence from the United States. Occupational Environmental Medicine
62: 588-97.
Folkard S and Lombardi DA (2006) Modeling the impact of the components
of long work hours on injuries and "accidents." American Journal of
Industrial Medicine 49: 953-63.
Folkard S and Lombardi DA (2004) Toward a "risk index" to assess work
schedules, Chronobiology International 21: 1063-72.
Knauth P (2007) Extended work periods. Industrial Health 45 (1):
125-36.
Smith L, Folkard S, Tucker P, and Macdonald I (1998) Work shift
duration: a review comparing either hour and 12 hour shift systems.
Occupational Environmental Medicine 55: 217-29.
Tucker P (2006) Compressed working weeks.
Conditions of Work and Employment Series No. 12. International
Labour Office - Geneva.
Vila B (2006) Impact of long work hours on police officers and the
communities they serve. American Journal of Industrial Medicine
49: 972-80.
Summary
The number of days off will vary in direct proportion to the length of
the shift. 12-hour shifts will provide twice as many scheduled days off
per year as 8-hour shifts.
The number of
weekends off will also increase with longer shifts, though other factors
such as the number of days worked in a row can have a larger impact.
For a given level of coverage, 8 and 12-hour shifts require the same
number of personnel (unless you offer fixed shifts). 10-hour shifts
usually take more personnel because you're scheduling for 30-hour days
(three 10-hour shifts).
10-hour shifts are not advised for level coverage requirements. They are
best suited for workloads that are higher for part of the day.
Printable Page (PDF)
|
