Contact-centre staffing with productivity and absence
The customer service centre handles 18,000 calls in a typical week. Average handling time is 6.5 minutes. Each agent is paid for 36 hours a week, but only 85% of paid time is productive; the rest is taken by breaks, team meetings and training. Absence averages 8% of paid hours. Management's service-level rule requires productive capacity equal to the forecast workload plus 20% spare capacity. For next year, planners forecast a 12% rise in call volume, while a new script is expected to cut average handling time by 8%. The centre currently employs 84 agents. The operations manager says: 'A 12% rise in calls means we need 12% more agents, so about 94.' A union representative argues that the 20% spare-capacity rule is unnecessary and that the centre could run with the bare workload figure. Assess both positions and calculate the staffing requirement before and after the forecast change.
1. Calculate the current staffing requirement with and without the 20% spare-capacity rule.
Read the worked answer
Current workload = 18,000 × 6.5 = 117,000 minutes = 1,950 hours. Productive hours per paid agent = 36 × 0.85 = 30.6. After 8% absence = 30.6 × 0.92 = 28.152 productive hours. Bare workload: 1,950 ÷ 28.152 = 69.27 → 70 agents. With the 20% rule: 1,950 × 1.2 = 2,340 productive hours needed; 2,340 ÷ 28.152 = 83.12 → 84 agents. The current 84 therefore matches the rule almost exactly. The union representative's bare-workload position would imply about 70 agents, 14 fewer, and would leave no planned cover beyond the 8% average absence. The 20% buffer is not the same as absence: it covers forecast error, call-arrival variability and the difference between average and peak workload.
2. Calculate the requirement for next year and assess the operations manager's 'about 94' figure.
Read the worked answer
Next year calls = 18,000 × 1.12 = 20,160. New handling time = 6.5 × 0.92 = 5.98 minutes. Workload = 20,160 × 5.98 = 120,556.8 minutes = 2,009.28 hours. With the 20% rule: 2,009.28 × 1.2 = 2,411.136 hours; ÷ 28.152 = 85.65 → 86 agents.
The manager's 94 is a volume-only calculation: 84 × 1.12 = 94.08. It ignores the 8% reduction in handling time. If the script change were not delivered, the requirement would be 20,160 × 6.5 = 131,040 minutes = 2,184 hours; × 1.2 = 2,620.8; ÷ 28.152 = 93.1 → 94 agents. So 94 is a contingency figure for no productivity gain, not the central forecast.
3. If only half of the expected handling-time reduction is achieved, what staffing is needed, and does 86 agents still satisfy the spare-capacity rule?
Read the worked answer
Half the reduction means handling time falls by 4%: 6.5 × 0.96 = 6.24 minutes. Workload = 20,160 × 6.24 = 125,798.4 minutes = 2,096.64 hours. With 20% buffer: 2,096.64 × 1.2 = 2,515.968 hours; ÷ 28.152 = 89.37 → 90 agents.
At 86 agents, available productive hours = 86 × 28.152 = 2,421.07. Against the central workload of 2,009.28, spare capacity = (2,421.07 − 2,009.28) ÷ 2,009.28 = 20.5%, so the rule is just met. But if only half the productivity gain materialises, 86 agents would be understaffed by about four. A staged plan-hire toward 86, with a trigger to add up to 90 if the handling-time reduction is not realised-is more defensible than fixing either number now.