Call Center Operations Case Interview: Capacity Case

Key facts for this case: type, industry, difficulty and firm style.
Case typeOperations
IndustryTravel / Customer Service
DifficultyHard
Firm styleBCG

The case prompt

Our client is TravelLine, an online travel booking platform. They recently centralized customer service from 12 regional offices into one national call center. The center is overwhelmed — customers face 20-plus minute wait times and satisfaction scores are dropping fast. The CEO needs to understand why and what to do about it.

TravelLine migrated 780,000 active customers from 12 regional offices to a single national call center over 50 weeks. The call center currently has 45 trained agents. Customers are experiencing 20+ minute wait times, and NPS has dropped 25 points. The CEO wants us to diagnose the root cause and recommend solutions.

The exhibits

Exhibit 1

Cumulative Customers Migrated to National Call Center (thousands)Cumulative customers migrated to the national call center (thousands), by week (weeks 0-50).

Cumulative Customers Migrated to National Call Center (thousands)

Cumulative customers migrated to the national call center (thousands), by week (weeks 0-50).

Show the data behind Exhibit 1
Cumulative Customers Migrated to National Call Center (thousands). Cumulative customers migrated to the national call center (thousands), by week (weeks 0-50).
Week05101520253035404550
Customers Migrated (K)050120200300420550650720760780

Exhibit 2

Call Center Capacity Driver TreeDriver tree linking weekly call volume and per-agent capacity to the number of required agents.

Call Center Capacity Driver Tree

Driver tree linking weekly call volume and per-agent capacity to the number of required agents.

Show the data behind Exhibit 2
Call Center Capacity Driver Tree. Driver tree linking weekly call volume and per-agent capacity to the number of required agents.
ComponentValueNotes
Average Call Time210 secondsTime on the phone with customer
Average Wrap-up Time90 secondsPost-call notes and system updates
Total Settlement Time300 seconds = 5 minCall time + wrap-up = 1/12 hour
Calls per Customer per Year2.5Average across all customer types
Weeks per Year52Used to convert annual customer calls to weekly calls
Working Hours per Week40 hoursStandard full-time schedule
Gross/Net Working Ratio78%Net of breaks, meetings, admin
Working Time Duration55%% of net time actually on calls
Effective Call Hours per Agent per Week17.16 hours40 x 78% x 55%
Seconds per Hour3,600Used to convert productive hours into call capacity
Calls Handled per Agent per Week~206 calls17.16 hrs x 12 calls/hr
Seasonal Peak Factor (Summer)1.3030% more calls June-August
TravelLine Call Center OptimizationBCG

Operations · hard

TravelLine Call Center Optimization

Travel / Customer Service

Practise this case free

How a strong candidate structures it

A strong call center operations framework

01
1.Demand analysis
a.Call volume drivers: customer base, call frequency, seasonality
b.Forecast demand growth as migration continues
02
1.Supply analysis
a.Agent capacity: hours, utilization, settlement time
b.Current vs required headcount
03
1.Gap diagnosis
a.Supply-demand mismatch quantification
b.Root cause of the gap
04
1.Solution levers
a.Demand reduction: self-service, IVR, chatbot, FAQ
b.Efficiency: reduce settlement time, better tools
c.Capacity: hiring, shift optimization, part-time agents
05
1.Prioritization and implementation

Question by question

  1. 1

    Case context

    Understand the Case

    Can you summarize the situation and what TravelLine needs from us?

  2. 2

    Clarifying

    Clarifying Questions

    What would you like to know before analyzing the problem?

  3. 3

    Structure

    Framework

    How would you structure your analysis of why the call center is overwhelmed?

    Drill the structure
  4. 4

    Analysis

    Driver Tree Setup

    Looking at Exhibit 2, walk me through the driver tree for calculating how many agents TravelLine needs. What are the key inputs?

    Drill the brainstorming
  5. 5

    Math

    Calculate Required Agents

    At Week 20, TravelLine had 300,000 customers migrated to the call center. Using the driver tree from Exhibit 2, calculate how many agents are needed at that point. Then calculate how many are needed at Week 50 with 780,000 customers. Compare both to the current 45 agents.

    Drill the math
  6. 6

    Analysis

    Gap Analysis and Constraints

    The call center has 45 agents but needs 182. Hiring takes 8 weeks per agent and the budget is limited. What are the key constraints, and what categories of solutions should TravelLine consider?

    Drill the brainstorming
  7. 7

    Math

    Quantify Solution Impact

    If self-service tools deflect 25% of calls and better CRM tools increase each agent's capacity by 10%, how many agents would TravelLine need at Week 50? How many do they still need to hire?

    Drill the math
  8. 8

    Synthesis

    Final Recommendation

    The CEO just walked in. Present your diagnosis and recommendations.

    Drill the synthesis

The worked path

The numbers that decide it

  • At Week 20 with 300K customers, TravelLine needs approximately 70 agents but only has 45
  • The agent gap of 25 (36% shortfall) explains the 20+ minute wait times
  • By Week 50 with 780K customers, the need grows to approximately 182 agents at baseline
  • Summer peak season adds 30% more call volume, requiring ~236 agents at peak
  • Three levers exist: reduce call volume, reduce settlement time, increase agent productivity
  • Self-service tools (IVR, chatbot, FAQ) could deflect 20-30% of simple calls
  • Reducing wrap-up time through better tools could cut settlement time by 15-20%
  • Part-time agents during peaks could increase effective capacity 10-15%
  • Long-term solution requires combination of all three levers plus strategic hiring

Analysis Flow

  1. 1

    Set up the demand equation

    Weekly call volume = (Customers / 52 weeks) × Calls per customer per year

    At Week 20 (300K customers): 300,000 / 52 × 2.5 = 14,423 calls/week

    At Week 50 (780K customers): 780,000 / 52 × 2.5 = 37,500 calls/week

  2. 2

    Calculate agent capacity

    Settlement time = 210 + 90 = 300 sec = 5 min = 1/12 hour

    Effective hours per agent = 40 × 78% × 55% = 17.16 hrs/week

    Calls per agent per week = 17.16 × 12 = ~206 calls/week

  3. 3

    Calculate required agents

    Week 20: 14,423 / 206 = ~70 agents needed

    Week 50: 37,500 / 206 = ~182 agents needed

    Week 50 peak season: 37,500 × 1.30 / 206 = ~236 agents needed

    Current staff: 45 agents

    • Gap at Week 20: 25 agents (36% shortfall)
    • Gap at Week 50: 137 agents (75% shortfall)
  4. 4

    Three solution levers

    Lever 1 — Reduce demand (call volume)

    • Implement IVR system to handle simple queries (booking confirmation, status checks)
    • Build self-service FAQ and chatbot for common issues
    • Estimated deflection: 20-30% of calls
    • Impact: reduces required agents by 20-30%

    Lever 2 — Reduce settlement time

    • Better CRM tools to reduce wrap-up time from 90 to 60 seconds
    • Pre-built response templates for common issues
    • Impact: settlement drops from 300 to 270 sec, ~10% more calls per agent

    Lever 3 — Increase capacity

    • Hire and train additional agents (8-week ramp)
    • Add part-time agents for peak hours and peak season
    • Cross-train back-office staff for overflow support
  5. 5

    Combined impact estimate

    Self-service deflects 25% of calls: 37,500 × 0.75 = 28,125 calls/week

    Better tools increase calls/agent by 10%: 206 × 1.10 = 227 calls/agent/week

    Required agents: 28,125 / 227 = ~124 agents (vs 182 without improvements)

    • Still need to hire ~79 additional agents beyond current 45

Recommendation

"The root cause is a massive supply-demand mismatch: TravelLine needs 182 agents at full migration but only has 45. Three actions in priority order: First, immediately deploy self-service tools (IVR, chatbot) to deflect 25% of calls — this is the fastest lever. Second, invest in better CRM tools to reduce settlement time by 10%. Third, begin hiring and training 80+ additional agents in waves, starting immediately given the 8-week training cycle. Combined, these reduce the requirement to ~124 agents, making the hiring target achievable."

TravelLine Call Center OptimizationBCG

Operations · hard

TravelLine Call Center Optimization

Travel / Customer Service

Practise this case free

Why this case

This travel customer-service case tests capacity planning after centralization, a trap generic operations cases often miss. The 20-plus-minute waits are not just a staffing problem: demand rises with customer migration, call time includes a 90-second wrap-up, and summer adds 30% volume. The industry-specific issue is protecting service quality while scaling a seasonal, distributed customer base.

FAQ

How do I calculate required agents in this call center case?
Estimate weekly calls from customers, calls per customer, and 52 weeks, then divide demand by weekly calls handled per agent. At Week 50, 780,000 customers create 37,500 weekly calls. With about 206 calls per agent per week, TravelLine needs approximately 182 agents before seasonal or operational improvements.
Why is hiring alone not the best answer?
Hiring addresses capacity but leaves demand and productivity unchanged. TravelLine can deflect 20% to 30% of simple calls through IVR, chatbots, and FAQs, while better tools can reduce wrap-up time and raise calls per agent by about 10%. Those levers reduce the number of agents needed and improve response times.
What are the three operational levers in this case?
Reduce call volume through self-service, reduce settlement time through better CRM tools and response templates, and increase capacity through hiring, part-time peak coverage, or cross-training. A strong answer ranks the levers by speed and impact, then combines them rather than presenting staffing as the only fix.
What should the recommendation say at Week 50?
State that TravelLine needs about 182 baseline agents but has 45, creating a 137-agent gap. Prioritize self-service, reduce wrap-up time, and hire in waves because training takes 8 weeks. With 25% call deflection and 10% productivity improvement, the requirement falls to about 124 agents, before the 30% summer peak.
TravelLine Call Center OptimizationBCG

Operations · hard

TravelLine Call Center Optimization

Travel / Customer Service

Practise this case free