Buyer/Customer demand is not always even flow. Sometimes they ask for a lot at once and other times they slowly decide while we have people on the bench waiting for a go signal. Let’s discuss a few heuristics.
One way of dealing with that is only using 85% of your capacity to leave a 15% reserve. This reserve can act as a buffer for the shocks to your system that come from a sudden surge of work demand.
You have to request management support for this to be a survivable approach because the cost for this "reserve" will be noticed and because the historical focus on maximizing staff utilization may prompt leaders to ask you to increase staff utilization from say 85% to 95%, or worse, 100%, leaving little to no reserve capacity. Reserves help even out demand spikes.
The other possible solution is to hire temporary staff as needed for the brief surges and keep your core staff from being overburdened. Also, try to reduce the delay time for hiring to as low as possible. If normal hiring cycle time is 50 days, try to reduce it. A hiring delay of only 15 days has less impact on your labor capacity than 50 days hiring cycle time. You may need a good relationship with the recruiter you use too.