It is fair to say that's one of the most important management roles in a call center is ensuring that there are enough agents to respond with the minimum amount of delay. The process of performing this is described as workforce planning. The process concentrates on estimating the “right” number of employees to work in different periods of time with the aim of achieving the required levels of service taking into account the cost and the quality of service. The workforce planning process in call centers is considered a complex task, as it depends heavily on the accuracy of forecasting that is heavily influenced by the customer’s decision. likewise, the outgoing calls are also affected by the customer availability and willingness to proceed with the response.

The Erlang-C formula is effective method used for workforce planning in call centers that was developed by the Danish mathematician Agner Erlang in 1917 , in the purposes of facilitating the decision of recruiting the right numbers of operators for the telephone system that was flourishing at the time . However, call centers nowadays are still performing workforce planning accordingly with few minor modifications. The formula measures the required staff by estimating of the expected call volume, required response times and average time to handle call.

Let's suppose a call center handle fifty calls per hour and each call takes about five minutes on average to be handled, and the SLA is requiring to respond to 90% of customers within one minute, then you will need ten agents working in that hour with an average occupancy of at least 60% of the time, this means we're assuming a 30% of staff shrinkage, which is perfectly ideal - the indicator of employee occupancy measures time spent on breaks, meetings, or any activities that don't involve direct interaction with the customer.

Scheduling shall take into consideration, the know-how skills of agents and other skill sets, and the adoption of an advanced workforce management system in which the group of agents are divided into several groups in order to match the company's requirements with the skills of agents. The number of groups should be extended when a multimedia environment is brought into the operation, which usually requires multiple skills to deal with media, email, live-chat, or high marketing capabilities to conduct sales activities. However, scheduling needs the availability of historical data that demonstrates the volume of calls and handling times, with consideration of the seasonal changes in workload such as campaigns, official holidays, times allocated for meetings or training, in addition, to adopting the flexibility in changing or developing schedules as Inaccurate forecasts combined with fixed schedules may cause significant failures in the quality of service.

The most common improper practice In the KSA is determining the number of agents required in the contractual phase with call centers instead of stating the service level of agreement and provide the vendors with the data shows the expecting volume of calls so that the vendors, in turn, propose the optimal number of agents to meet the service expectation. These practices have limited the competition as the monthly cost of the agent in most of the local call centers is almost identical, in addition, this practice may lead to recruiting less or more than the right number of agents if it is not estimated according to appropriate methodology.