Cost Reduction Case Interview: Framework, Worked Examples, and Common Traps (2026)

A cost reduction case asks where a company can cut costs without damaging revenue or competitive position. The framework: build a MECE cost tree (fixed vs. variable or by value chain), identify the 2-3 largest buckets, benchmark against industry averages, then recommend specific cuts with quantified savings and timelines. Cost reduction cases appear in approximately 15-20% of first-round MBB interviews, often embedded within profitability or operations cases (My Consulting Offer).

Two Cost Tree Approaches

Choose one approach based on industry — using both simultaneously creates overlapping categories.

Fixed vs. Variable (default for services and SaaS)

Value Chain (best for manufacturing, retail, CPG)

The value chain approach is more powerful for manufacturing because it maps directly to operational processes (Hacking the Case Interview).

The 4-Step Method

Step 1 — Map the cost base. Request a cost breakdown by category as a percentage of revenue. If total costs are $200M, quantify each bucket immediately: Procurement $80M (40%), Production $50M (25%), Distribution $30M (15%), SG&A $25M (12.5%), Overhead $15M (7.5%).

Step 2 — Benchmark. Compare each category to competitors or to the client's own performance 3 years ago (My Consulting Coach). Common benchmarks: COGS as % of revenue is 50-65% for manufacturing, 15-25% for SaaS; SG&A is 15-25% across most industries.

Step 3 — Identify reduction levers. For each over-indexed category, propose 2-3 specific levers with typical savings:

Step 4 — Prioritize. Rank by impact (dollar savings), feasibility (execution difficulty), and speed (time to realize savings). Recommend the "high impact, high feasibility" initiatives first.

Worked Example: Manufacturing Cost Reduction

Prompt: An auto parts manufacturer has $400M revenue and 6% operating margin versus the 10% industry average. Close the gap.

Cost baseline and gaps:

Savings needed: $16M (from 6% to 10% margin on $400M)

Recommendations:

1. Procurement consolidation — Reduce from 23 steel suppliers to 8-10 with competitive bids. Savings: $16-19M. Timeline: 6-9 months.
2. Production automation — $5M investment in robotic welding for 3 highest-volume lines. Savings: $6.4M/year (8% labor reduction). Payback: under 12 months.
3. Energy optimization — Shift 40% of production to off-peak hours. Savings: $1.7M. Timeline: 3 months.

Total potential: $24-27M (exceeds $16M target, providing execution buffer). Sequence by speed: energy first (3 months), procurement second (6-9 months), automation third (12 months).

Worked Example: SaaS Cost Reduction

Prompt: A B2B SaaS company has $120M ARR and a -5% operating margin. The board wants profitability within 12 months.

Cost baseline and gaps vs. profitable SaaS benchmarks:

Minimum savings needed: $6M (from -$6M loss to breakeven)

Recommendations:

1. Engineering rationalization — Pause 2 of 5 product initiatives serving less than 5% of customers. Reduce headcount 15% via attrition and selective layoffs. Savings: $6.3M minus $1.5M severance = $4.8M net year-1.
2. Cloud optimization — Migrate to reserved pricing (30-40% savings per instance), right-size databases. Savings: $4-5M. Timeline: 3-6 months.
3. G&A consolidation — Outsource payroll and basic accounting, reduce headcount 20%. Savings: $3.6M.

Total net year-1: $12-13M (2x the minimum). Do not cut customer success — if 12% annual churn rises even 2 points, that destroys $2.4M in recurring revenue.

Common Traps

Advanced Levers

Zero-based budgeting (ZBB): Require every department to justify every dollar from zero, rather than adjusting last year's budget. ZBB typically surfaces 10-25% in "zombie costs" that persist without scrutiny (Highbridge Academy).

Shared services consolidation: Centralize finance, HR, and IT across business units. Saves 20-30% on back-office costs by eliminating duplication.

Demand management: Reduce demand for internal services rather than cutting supply. Example: cutting financial reports from 47 to 12 saves more analyst time than hiring fewer analysts.

Related Guides

• Profitability Framework — cost reduction is one half of the profit equation
• Operations Cost Framework — deeper dive on supply chain and process optimization
• Value Chain Framework — maps cost leaks across the value chain
• M&A Case Framework — cost synergies in acquisition cases
• Consulting Math Formulas — break-even and contribution margin calculations

Test Your Understanding

Test yourself

1 / 3

Question 1 of 3

A manufacturing client spends $80M on raw materials using 23 suppliers. You recommend consolidating to 8 suppliers. What is the most likely savings range?

• A1-3% ($0.8M-$2.4M)
• B10-15% ($8M-$12M)
• C30-40% ($24M-$32M)

Sources

• My Consulting Offer — Cost Reduction Case Interview (accessed March 20, 2026)
• Hacking the Case Interview — Cost Reduction Case Interview (accessed March 20, 2026)
• Highbridge Academy — Master Cost Reduction Cases (accessed March 20, 2026)
• My Consulting Coach — Implications of Cost Structure (accessed March 20, 2026)
• Roger Martin — Dangerous Cost Reduction Projects (accessed March 20, 2026)
• PrepLounge — Fixed & Variable Costs (accessed March 20, 2026)