How to prevent double-booking employees
A double booking wastes a wage, leaves a gap somewhere else or sends home a person who made the trip for nothing. It is almost always a process problem rather than a people problem. Here are the ways double bookings happen, the checks that catch them before the roster goes out, and the rules that stop them creeping back in through swaps, cover and second venues.
Double booking covers three different mistakes, and it helps to name them because each has a different fix. A person can be booked for two shifts that overlap. A shift can be given to two people. Or a person can be rostered while they are on approved leave or outside the availability they gave. All three usually happen for the same reason: more than one version of the roster, or more than one person changing it.
The weekly checks for any roster are in how to create a weekly roster in Excel, and rotations have traps of their own, covered in how to create a rotating roster without double-booking staff. This article is about the day to day: keeping a roster free of double bookings as it is built and changed.
The three kinds of double booking
| Kind | Example | What it costs |
|---|---|---|
| One person, two shifts at once | Mia is rostered at the cafe from 7:00 to 11:00 and at the second site from 10:30 to 15:00 on the same Saturday | One site starts short, and cover is found at the last minute |
| One shift, two people | A Saturday close offered in a group chat is accepted by two casuals within a minute of each other | Two people turn up, and one is sent home or paid for time that was not needed |
| Booked while unavailable | Sam is rostered on a Tuesday in a week of approved annual leave | A no show that was never a no show, and a gap found on the morning |
The second kind has a cost the award sets. Under clause 11.3 of both the Hospitality and Restaurant awards, a casual must be engaged and paid for at least 2 consecutive hours each time they are required to attend work, so a casual sent home because the shift was already filled is still owed those 2 hours. Under the General Retail award, the casual minimum engagement is 3 hours (clause 11.2). Rules differ between awards, so check yours with the Fair Work Ombudsman’s Find my award tool.
Where double bookings come from
- More than one copy. A printed roster on the wall, a spreadsheet on the laptop and screenshots in a group chat drift apart, and each change reaches only one of them.
- More than one person making changes. Two supervisors each fill the same gap without knowing the other has.
- Offers that stay open. A shift offered to everyone is taken by the first person to reply, and the second person never hears it has gone.
- Leave and availability kept somewhere else. Leave is approved in a text message and never reaches the roster.
- Swaps agreed between staff. Two people swap, one of them already has a shift that overlaps, and nobody checks.
- Two venues or two teams. Each roster is right on its own, but the same person appears on both.
- Shifts that cross midnight. A close that finishes at 1:00 belongs to two dates, so a check that only compares shifts on the same date can miss a clash in the early hours of the next day.
One roster and one set of hands
- Keep one master rosterDecide where the real roster lives, whether that is a spreadsheet, a board or an app, and treat every printout, screenshot and message as a copy. Changes are made on the master first and copied out after.
- Name who can change itGive one person, or one person for each shift, the job of approving changes. Other supervisors can suggest a change, but it is not real until it is on the master.
- Put availability and leave on the rosterRecord approved leave and each person’s availability where the roster is built, so a clash shows up as you place the shift rather than on the day.
- Close every offerWhen a shift is offered to a group, say who has taken it as soon as it is filled, in the same place it was offered.
- Check before you publishRun the overlap check below on the whole roster before it goes out, and again after any change.
The staff availability template and the leave request template give you a written record of both, so neither lives only in a message thread.
A spreadsheet check for overlapping shifts
If your roster is a spreadsheet with one row for each shift, one formula can flag anyone booked into two shifts that overlap on the same date. It assumes the date is in column A, the name in column C, the start time in column E and the finish time in column F, with shifts in rows 2 to 200 and times entered as times. In a spare column on row 2, enter this and fill it down:
=SUMPRODUCT(($C$2:$C$200=C2)*($A$2:$A$200=A2)*($E$2:$E$200<F2)*($F$2:$F$200>E2))>1For each shift, it counts the shifts for the same person on the same date that start before this one finishes and finish after this one starts. Every shift overlaps itself, so a count above 1 means a second, overlapping shift, and the cell shows TRUE. Shifts that end exactly when the next begins are not flagged. The formula does not handle shifts that cross midnight, so split those into two rows, one each side of midnight, or check them by eye.
| Name | Start | Finish | Result |
|---|---|---|---|
| Mia | 7:00 | 11:00 | TRUE |
| Mia | 10:30 | 15:00 | TRUE |
| Sam | 7:00 | 11:00 | FALSE |
| Sam | 11:00 | 15:00 | FALSE |
Mia’s shifts overlap from 10:30 to 11:00, so both rows are flagged. Sam’s shifts meet at 11:00 without overlapping, so neither is. If Sam’s two shifts are at different venues, though, back to back shifts leave no time to travel, which is worth a check of its own.
To catch a shift given to two people, count the names rostered for each role and start time and compare the count with the number you need. A COUNTIFS on date, role and start time that comes back higher than planned is a shift with one person too many.
Rules for swaps, cover and extra shifts
Most double bookings in a published roster arrive through changes, not the first draft. A few rules stop them.
- A swap is a request until it is approved. Check that the person taking the shift has nothing overlapping it and is available, then change the master. The shift swap request template keeps a record of who asked and who approved.
- Cover comes from one list. When someone calls in sick, one person works through a short list of people who can cover, so two supervisors do not each find someone. Managing hospitality roster changes and sick calls sets out an order for it.
- Open shifts are offered once and closed. Post the shift in one place with a closing time, and tell everyone when it has gone.
- Extra shifts are checked against the whole week. Before adding a shift, look at the person’s other shifts that week, including at any other venue.
Changes can also break award rules that an overlap check will not show. A shift that ends at 23:00 followed by one that starts at 7:00 the next morning is not a double booking, but it leaves only an 8 hour break. For employees other than casuals, the Restaurant award requires at least 10 hours between finishing one day and starting the next, or 8 at a changeover of rosters (clause 15.1), and the Hospitality award sets the same break for full-time and part-time employees (clause 15.5). The General Retail award requires 12 hours unless the employer and employee agree to 10 (clause 16.6). A part-time employee under the Restaurant or Hospitality award must also not be rostered outside their agreed availability (clause 10.7).
When the same person works at two venues
Businesses with more than one site double book people most often, because each site’s roster tends to be built on its own. Build both rosters in one place, or at least check everyone who works at both sites against both rosters before either is published. Allow travel time between sites, and total each person’s hours across both before checking them against the daily and weekly limits in the award. The glossary entry on multi-venue rostering covers the terms.
Check again after every change
Most rosters are checked once, when they are built, and then changed a dozen times. Run the same checks after every change that touches someone’s hours: overlapping shifts, availability and leave, breaks between shifts and the total for the week. Then send the updated roster to everyone, not only the people involved, so there is one current version. How far in advance to publish a staff roster covers the notice to give for changes once a roster is out.
Roster Flow keeps one roster for everyone: availability and leave from staff phones, the roster published to everybody at once, clock ins that become timesheets, and approved hours sent to Xero, MYOB or a CSV file.
A checklist against double booking
- There is one master roster, and every other copy is treated as a copy
- One named person approves changes for each shift
- Approved leave and current availability are on the roster
- The overlap check runs before publishing and after every change
- Every open shift has a closing time and is marked filled once taken
- Swaps are approved only after checking the person taking the shift
- Anyone working at two venues is checked across both rosters
- Breaks between shifts still meet the award after every change
Questions
What does double-booking an employee mean?
Rostering one person for two shifts that overlap, or giving one shift to two people. Rostering someone during approved leave causes the same problem and is caught the same way.
Do I have to pay a casual who turns up to a shift that was double booked?
Under the Hospitality and Restaurant awards, a casual must be engaged and paid for at least 2 consecutive hours each time they are required to attend work (clause 11.3), so sending them home does not avoid that. Other awards set different minimums, such as 3 hours in the General Retail award.
How do I find overlapping shifts in Excel?
Use SUMPRODUCT to count the shifts for the same person and date that start before a shift finishes and finish after it starts. A count above 1 means an overlap.
Is a late close followed by an early open a double booking?
No, but it may break the break between shifts: 10 hours under the Restaurant award for employees other than casuals, or 12 hours under the General Retail award unless 10 is agreed.
How do I stop two people accepting the same open shift?
Offer it in one place with a closing time, give it to the first person who accepts, and tell everyone straight away that it has been filled.
Who should be allowed to change the roster?
As few people as practical, with one named person approving changes for each shift, so the same gap is never filled twice.
Sources
- Fair Work Commission: Hospitality Industry (General) Award 2020 [MA000009]
- Fair Work Commission: Restaurant Industry Award 2020 [MA000119]
- Fair Work Commission: General Retail Industry Award 2020 [MA000004]
- Fair Work Ombudsman: find my award