How to staff for a spike, a campaign or a product launch
A known uplift on an existing line: size it in contacts, give it a shape, see what it does to the requirement, and choose between overtime, borrowing and delay.
Published
A spike is a forecast with a known cause: a bill run, a campaign, a launch, an outage. Because the cause is known, the shape is usually knowable too, and the staffing question becomes a choice between covering it and accepting the service level it costs. This guide is the method, with the calculators that carry the numbers.
Size the uplift in contacts, not per cent
“Twenty per cent more” hides the question. Twenty per cent of what, over what period, with what shape? Get to a number of extra contacts and when they arrive. For a campaign: audience reached times response rate times the share who contact, spread over the days after each burst. For a bill run: bills sent times the contact rate from the last run, landing over three days with the first heaviest. For an outage: the customers affected times a contact rate that starts high and decays.
Write the driver and the contact rate down separately, as with any forecast without history, so you can see which was wrong afterwards.
Give it a shape
Spikes rarely follow the normal day. A television advert at 19:30 puts its contacts in the 19:30 to 21:00 intervals, when the normal curve is falling. An email at 09:00 lands in the morning peak, on top of it. Add the spike’s contacts to the intervals it lands in, not to the day’s total, and paste the resulting intervals into the planner. The requirement will show the spike as its own peak, and it is that peak that has to be covered.
Run the requirement with and without it
Two planner runs: the normal day, and the day with the spike’s intervals added. The difference in agents per interval is what the spike costs; the difference in agent-hours is what covering it costs. Save both as scenarios in the calculators and the deltas do the sums.
Decide how to cover it
- Move shrinkage first. Coaching, training, meetings and flexible breaks out of the spike’s intervals. Free, and often enough for a modest uplift.
- Overtime for the peak intervals only. The shortfall calculator prices it against agency cover and borrowed agents. Overtime for the whole day pays for hours the spike does not need.
- Borrow from a quieter team for the days of the spike. The pooling arithmetic works in your favour here: a borrowed agent who can take the spike’s contacts is worth more than a new hire who cannot.
- Accept the service level cost and say so in advance. An outage response with a 60 per cent service level for two hours, announced, is a plan; the same thing unannounced is a failure.
- Move the cause. Sometimes the cheapest option is a bill run on a Tuesday instead of a Monday, or a campaign that goes out at 14:00 instead of 09:00. The requirement curve is the evidence for that conversation.
During the spike
The estimate will be wrong in one direction or the other. Run the intraday reforecast after the first two or three intervals of the spike, with heavy damping, and adjust the afternoon before it arrives.
Try it
Paste a normal day’s intervals, then add the spike to the intervals it lands in and compare.
90% of rostered hours land on the curve.
- On the phones
- Shrinkage allowance
- Theoretical FTE
- 59.3
- Agent-hours per week
- 2,225.0 h
- Agent-hours per day
- 445.0 h
- Peak interval
- 53 at 11:00
- Average scheduled
- 37.1
- Contacts per day
- 3,000
Weekly scheduled agent-hours ÷ contracted hours.
5 open days.
37 on the phones for 187 contacts.
Across the open day.
15,000 a week.
Show the working
- 3000 contacts per day is the average open day: 15000 a week across 5 open days, spread over 8:00 to 20:00 in 30-minute intervals using the "Morning and afternoon peaks" shape.
- The day-of-week split is even, so every open day carries 3000 contacts.
- Each interval runs Erlang C for 80% within 20 s, adds agents until occupancy is at or below 85%, then divides by (1 − 30%) and rounds up.
- Mon's peak is 11:00: 187 contacts need 37 on the phones and 53 scheduled.
- Agent-hours per day = Σ scheduled × 30 ÷ 60 = 445.0 h; × 5 days = 2225.0 h a week.
- FTE = 2225.0 ÷ 37.5 contracted hours = 59.3. Shrinkage is already in the per-interval numbers, so contracted hours are the right divisor.
- At 90% roster efficiency, 59.3 ÷ 0.90 = 65.9 FTE to cover the curve with real shifts.
This is one typical day. Pebble WFM does every day from your forecast, then builds and publishes the roster. Free month, no card needed.
Where next
- How to forecast with no history: the same method when the whole line is new.
- Where to put breaks against the curve: the free option, in detail.
Frequently asked questions
- Marketing says the campaign will add 20 per cent to volume. What do I do with that?
- Ask what it is 20 per cent of and when it lands. A 20 per cent uplift on the day spread evenly is manageable; the same volume in the two hours after a television advert is not. The shape of the spike matters more than its size, and marketing usually knows it.
- How much notice do I need?
- Two weeks to move breaks and coaching, three to arrange overtime, six to borrow agents from another team, twelve to recruit. Anything shorter than two weeks is managed on the day with the intraday reforecast, and the campaign should be told what that will cost in service level.
Stop doing this one interval at a time
Pebble WFM forecasts your demand, computes the staffing requirement for every interval, builds the roster and publishes it, with self-service for agents and a copilot that can do what a planner can. Explore a sample organisation on day one.