The Math of Contact Center Staffing

Transcription

1 3/14/ Annual Conference The Math of Contact Center ing Session Overview In this session, you will learn to: Outline the implications of overstaffing and understaffing. Identify the unique characteristics and requirements for inbound call center staffing. Identify staffing models for inbound call centers. Calculate staff requirements to meet service goals. Identify basic call center staffing tradeoffs. Identify small versus large group size considerations. Outline steps for staffing for outbound calls, s, and chat contacts. 1

2 Call Center ing Call center success depends on getting the right number of people for each period of the day to answer incoming contacts at a desirable level of service while minimizing cost Implications of Getting it Wrong Overstaffing Understaffing When considering the impact of adding or subtracting staff, consider the impact on three main stakeholder groups: Customers Frontline Management 2

3 Impact on The Customer Overstaffing Faster service Expectation of future service Understaffing Long delays Reduced quality of service Abandoned calls Service Implications Think about the wait in queue from the customer s perspective. 3

4 Queue Perspectives In-Person Queue See the queue Select a queue Watch progress Estimate time Queue Perspectives Telephone Queue Invisible queue Limited choices No sign of progress No idea of time 4

5 Impact on Frontline Overstaffing More idle time Less productive Boredom Understaffing Less idle time More stress Angry callers Impact on Management Overstaffing Excessive costs Lower productivity Understaffing Unhappy callers Unhappy staff Higher phone costs Abandoned calls 5

6 Calculating Contact Center Workload Workload = Call Volume x Average Handle Time (AHT) (expressed in hours of work in a one-hour period) For AHT in minutes, divide by 60 / For AHT in seconds, divide by 3600 Example: 400 calls per hour, AHT = 180 seconds 400 x 180 / 3600 = 20 hours or erlangs Workload Arrivals 20 Hours Sequential Versus Random Workload How many staff? 6

7 Workload Arrivals 20 Hours Sequential Versus Random Workload 20 staff > 20 staff Defining Speed of Answer Goals Service level x% of calls answered in y seconds Average speed of answer (ASA) (Average delay of all calls including calls with no wait) 7

8 A Discussion About Setting Service Goals What is your service goal? When did you set the goal? How do you measure success? How do you compare to others? A View of Service Level Time of Day Call Volume Daily % SL (in 20 sec) 6:00 7: % 100% 7:00 8: % 95% 8:00 9: % 95% 9:00 10: % 90% 10:00 11: % 75% 11:00 12: % 70% 12:00 1: % 80% 1:00 2: % 80% 2:00 3: % 65% 3:00 4: % 70% 4:00 5: % 80% 5:00 6: % 85% 8

9 ing for Service Goal with Erlang C 1. Calculate staff workload. Call volume: 400 calls Talk time: Wrap-up time: AHT: 150 sec 30 sec 180 sec Workload = 400 x 180 / 3600 sec/hour = 20 hours 2. Define service goal. Desired speed of answer = ASA <30 seconds 3. Determine staff to meet service objective. ing Calculations Need model to predict what will happen in simple incoming call situation with: Erlangs of workload Varying staffing levels Erlang C assumptions Random call arrivals Infinite queue Other traffic models Erlang-Engset (smooth workload) Equivalent Random Theory (peaked traffic) 9

10 ing Calculations Erlang C will fit most simple call center staffing scenarios Erlang C Formula: where:" A is the total traffic offered in units of erlangs! N is the number of servers! PW is the probability that a customer has to wait for service ing with Erlang C Workload Hours Number of ASA Service Level (30 sec) Occupancy sec 35% sec 59% sec 75% sec 85% sec 91% sec 94%.77 10

11 ing Tradeoffs Evaluate staffing decisions with these tradeoffs in mind: Customer Impact What is delay time with +/- one agent? Frontline Impact What is occupancy rate with +/- one agent? Management Impact What are the financial implications? Service Tradeoffs Workload Hours Number of ASA Service Level (30 sec) Occupancy sec 35% sec 59% sec 75% sec 85% sec 91% sec 94%.77 What is the impact on service when staff are added or subtracted? 11

12 Productivity Tradeoffs Workload Hours Number of ASA Service Level (30 sec) Occupancy sec 35% sec 59% sec 75% sec 85% sec 91% sec 94%.77 What is the impact on occupancy when staff are added or subtracted? Financial Tradeoffs Workload Hours Number of ASA Occupancy sec seconds sec sec sec sec sec.77 What is the impact on revenues and costs when staff are added or subtracted? 12

13 Telephone Costs 1. Determine additional queue time with missing staff. ASA of 137 versus 51 seconds = 86 seconds per call 2. Multiply by number of calls. 400 calls x 86 seconds per call = 34,400 seconds 3. Calculate number of minutes. 34,400 / 60 = 573 minutes of additional queue time 4. Apply average cost per minute of telephone service per minute = $ per hour Impact of Size Calls /Hour Workload Number of Occupancy Level Service Level hours 23 87% 75% hours 24 83% 85% hours 25 80% 91% hours 44 91% 78% hours 45 89% 85% hours 46 87% 90% hours 85 94% 79% hours 86 93% 85% hours 87 92% 89% 13

14 ing for Other Contacts Communications with customers occurs over many channels: Inbound phone calls Outbound phone calls Chat Calculating Contact Center Workload Workload = Contact Volume x Average Handle Time (AHT) (expressed in hours of work in a one-hour period) Incoming Call Example: 400 calls per hour, AHT = 180 seconds 400 x 180 / 3600 = 20 hours or erlangs Workload calculations be different for: Outbound calls Chat 14

15 Calculating AHT for Outbound Calls In addition to talk time and after-call work, consider front-end set-up time for outbound calls. Components of Set-Up Time: Looking up number Dialing Waiting for network connect Waiting for customer connect Time on non-connects Calculating Set-Up Time Call Volume Type of Call Set-up Time Talk Time 40 Answered call 40 Voice mail 15 Busy signal 5 No Answer 32 sec 135 sec 34 sec 0 sec 22 sec 0 sec 46 sec 0 sec 100 calls All Calls 3200 sec 5400 sec 15

16 Call Set-up Time Manual Dialing Results: 3200 seconds set-up 5400 seconds talk time 8600 seconds total time In this example, 37% of staff time has been spent in just placing the calls. Don t forget to include this in handle time calculations. Calculating Workload for Other Contacts Considerations for Handle Time: Is history available? When does begin and end? Considerations for Chat Handle Time: Is history available? How many simultaneous chats? 16

17 Selecting a ing Model Contact Type Work Pattern Model Outbound calls Sequential Ratio Sequential Ratio Chat Random Erlang C (modified) Session Review In this session, you learned to: Outline the implications of overstaffing and understaffing. Identify the unique characteristics and requirements for inbound call center staffing. Identify staffing models for inbound call centers. Calculate staff requirements to meet service goals. Identify basic call center staffing tradeoffs. Identify small versus large group size considerations. Outline steps for staffing for outbound calls, s, and chat contacts. 17